Rev.4.1_00
SUPER-SMALL PACKAGE PWM CONTROL,
PWM/PFM SWITCHING CONTROL
STEP-UP SWITCHING REGULATOR S-8355/56/57/58 Series
Seiko Instruments Inc. 1
The S-8355/56/57/58 Series is a CMOS step-up switching regulator
which mainly consists of a reference voltage source, an oscillation
circuit, an error amplifier, a phase compensation circuit, a PWM
control circuit (S-8355/57) and a PWM/PFM switching control circuit
(S-8356/58). With an external low-on-resistance Nch Power MOS,
this product is ideal for applications requiring high efficiency and a
high output current.
The S-8355/57 Series realizes low ripple, high efficiency, and
excellent transient characteristics due to a PWM control circuit whose
duty ratio can be varied from 0% to 83% (from 0% to 78% for 250 kHz,
300 kHz, and 600 kHz models), an excellently designed error amplifier
and a phase compensation circuit.
S-8356/58 Series operation can be switched under a light load to a
PFM control circuit with a duty ratio of 15% via a PWM/PFM switching
control circuit to prevent a decline in the efficiency due to the IC
operating current.
Features
• Low voltage operation: Startup is guaranteed from 0.9 V (IOUT = 1 mA)
• Low current consumption: During operation: 25.9 µA (3.3 V, 100 kHz, typ.)
During shutdown: 0.5 µA (max.)
• Duty ratio: Built-in PWM/PFM switching control circuit (S-8356/58)
15 to 83% (100 kHz models), 15 to 78% (250 kHz, 300 kHz, and 600 kHz models)
• External parts: Coil, diode, capacitor, and transistor
• Output voltage: Can be set between 1.5 and 6.5 V (for VDD/VOUT separate types) or 2.0 and 6.5 V (for other than
V
DD/VOUT separate types) in 0.1 V steps. Accuracy of ±2.4%.
• Oscillation frequency: 100 kHz, 250 kHz, 300 kHz, 600 kHz
• Soft start function: 6 ms (100 kHz, typ.)
• Shutdown function
Packages
• SOT-89-3 (Package code: UP003-A)
• SOT-23-3 (Package code: MP003-A)
• SOT-23-5 (Package code: MP005-A)
• 6-Pin SNB(B) (Package code: BD006-A)
Applications
• Power supplies for portable equipment such as digital cameras, electronic notebooks, and PDAs
• Power supplies for audio equipment such as portable CD/MD players
• Constant voltage power supplies for cameras, video equipment, and communications equipment
• Power supplies for microprocessors
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
2 Seiko Instruments Inc.
Block Diagram
(1) S-8357/58 Series B, H, F Type
(
Without shutdown function)
(2) S-8357/58 Series B, H, F, N Type (With shutdown function)
Figure 1 Figure 2
(3) S-8357/58 Series E, J, G, P Type
(
VDD/VOUT separate type)
(4) S-8355/56 Series K, L, M, Q Type
Figure 3 Figure 4
-
+
EXT
VOUT
VSS
VDD
IC internal
power
supply
PWM or PWM
/PFM switching
control circuit
Phase
compensation
circuit
Soft start
built-in reference
power supply
Oscillation
Circuit
-
+
Soft start
built-in reference
power supply
IC internal
power
supply
VOUT
EXT
VSS
Phase
compensation
circuit
VDD
Oscillation
Circuit
ON/OFF
PWM or PWM
/PFM switching
control circuit
-
+
IC internal
power supply
VOUT
EXT
VSS
PWM or PWM
/PFM switching
control circuit
Soft start
built-in reference
power supply
Phase
compensation
circuit
Oscillation
Circuit
-
+
IC internal
power supply
VOUT
VSS
PWM or PWM
/PFM switching
control circuit
Soft start
built-in reference
power supply
EXT
Oscillation
Circuit
ON/OFF
Phase
compensation
circuit
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
3
Selection Guide
• The control types, product types, output voltage, and packages for the S-8355/56/57/58 Series can be
selected at the user’s request. Please refer to the “Product name selection guide” for the definition of
the product name and “Product Name List” for the full product names.
1. Function List
1-1. PWM control products
Table 1
Product Name
Switching
Frequency
(kHz)
Shutdown
Function
VDD/VOUT
Separate
Type
Package Application
S-8355KxxMC 100 Yes Yes SOT-23-5 Applications requiring variable output voltage and a shutdown function
S-8355LxxMC/BD 250 Yes Yes SOT-23-5/6-Pin SNB(B) Applications requiring variable output voltage, a shutdown function, and a thin coil
S-8355MxxMC/BD 300 Yes Yes SOT-23-5/6 Pin-SNB(B) Applications requiring variable output voltage, a shutdown function, and a thin coil
S-8355QxxMC/BD 600 Yes Yes SOT-23-5/6-Pin SNB(B) Applications requiring variable output voltage, a shutdown function, and a thin coil
S-8357BxxMC 100 Yes SOT-23-5 Applications requiring a shutdown function
S-8357BxxMA 100 SOT-23-3 Applications not requiring a shutdown function
S-8357BxxUA 100 SOT-89-3 Applications not requiring a shutdown function
S-8357ExxMC 100 Yes SOT-23-5 Applications in which output voltage is adjusted by external resistor
S-8357FxxMC/BD 300 Yes SOT-23-5/6-Pin SNB(B) Applications requiring a shutdown function and a thin coil
S-8357GxxMC/BD 300 Yes SOT-23-5/6-Pin SNB(B) Applications requiring variable output voltage and a thin coil
S-8357HxxMC/BD 250 Yes SOT-23-5/6-Pin SNB(B) Applications requiring a shutdown function and a thin coil
S-8357JxxMC/BD 250 Yes SOT-23-5/6-Pin SNB(B)
Applications requiring variable output voltage with an external resistor and a thin
coil
S-8357NxxMC/BD 600 Yes SOT-23-5/6-Pin SNB(B) Applications requiring a shutdown function and a thin coil
S-8357PxxMC/BD 600 Yes SOT-23-5/6-Pin SNB(B)
Applications requiring variable output voltage with an external resistor and a thin
coil
1-2. PWM/PFM switching control products
Table 2
Product name
Switching
Frequency
(kHz)
Shutdown
Function
VDD/VOUT
Separate
Type
Package Application
S-8356KxxMC 100 Yes Yes SOT-23-5 Applications requiring variable output voltage and a shutdown function
S-8356LxxMC/BD 250 Yes Yes SOT-23-5/6-Pin SNB(B) Applications requiring variable output voltage, a shutdown function, and a thin coil
S-8356MxxMC/BD 300 Yes Yes SOT-23-5/6-Pin SNB(B) Applications requiring variable output voltage, a shutdown function, and a thin coil
S-8356QxxMC/BD 600 Yes Yes SOT-23-5/6-Pin SNB(B) Applications requiring variable output voltage, a shutdown function, and a thin coil
S-8358BxxMC 100 Yes SOT-23-5 Applications requiring a shutdown function
S-8358BxxMA 100 SOT-23-3 Applications not requiring a shutdown function
S-8358BxxUA 100 SOT-89-3 Applications not requiring a shutdown function
S-8358ExxMC 100 Yes SOT-23-5 Applications in which output voltage is adjusted by external resistor
S-8358FxxMC/BD 300 Yes SOT-23-5/6-Pin SNB(B) Applications requiring a shutdown function and a thin coil
S-8358GxxMC/BD 300 Yes SOT-23-5/6-Pin SNB(B) Applications requiring variable output voltage and a thin coil
S-8358HxxMC/BD 250 Yes SOT-23-5/6-Pin SNB(B) Applications requiring a shutdown function and a thin coil
S-8358JxxMC/BD 250 Yes SOT-23-5/6-Pin SNB(B)
Applications requiring variable output voltage with an external resistor and a thin
coil
S-8358NxxMC/BD 600 Yes SOT-23-5/6-Pin SNB(B) Applications requiring a shutdown function and a thin coil
S-8358PxxMC/BD 600 Yes SOT-23-5/6-Pin SNB(B)
Applications requiring variable output voltage with an external resistor and a thin
coil
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
4 Seiko Instruments Inc.
2. Package and Function List by Product Type
Table 3
Series Name Type Package Name
(Abbreviation)
Shutdown
Function
Yes/No
VDD/VOUT
Separate Type
Yes/No
S-8355 Series
S-8356 Series
K, L, M, Q
(Shutdown function + VDD/VOUT separate type)
K = 100 kHz, L = 250 kHz, M = 300 kHz, Q = 600 kHz
MC/BD Yes Yes
MA/UA No
B, H, F
(Normal product)
B = 100 kHz, H = 250 kHz, F = 300 kHz
MC/BD Yes
No
N
(Normal product)
N = 600 kHz
MC/BD Yes No
S-8357 Series
E, J, G, P
(VDD/VOUT separate type)
E = 100 kHz, J = 250 kHz, G = 300 kHz, P = 600 kHz
MC/BD No Yes
MA/UA No
B, H, F
(Normal product)
B = 100 kHz, H = 250 kHz, F = 300 kHz
MC/BD Yes
No
N
(Normal product)
N = 600 kHz
MC/BD Yes No
S-8358 Series
E, J, G, P
(VDD /VOUT separate type)
E = 100 kHz, J = 250 kHz, G = 300 kHz, P = 600 kHz
MC/BD No Yes
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
5
3. Product Name
S-835 x x xx xx - xxx - Tx
IC direction in tape specifications*1
T2: SOT-89-3, SOT-23-3, SOT-23-5
TF: 6-Pin SNB(B)
Product name (abbreviation)*2
Package name (abbreviation)
UA: SOT-89-3
MA: SOT-23-3
MC: SOT-23-5
BD: 6-Pin-SNB(B)
Output voltage 15 to 65 (Ex. When the output voltage is 1.5 V, it is expressed as 15.)
Product type
B: Normal product, fOSC = 100 kHz (S-8357/58)
H: Normal product, fOSC = 250 kHz (S-8357/58)
F: Normal product, fOSC = 300 kHz (S-8357/58)
N: Normal product, fOSC = 600 kHz (S-8357/58)
E: VDD/VOUT separate type, fOSC = 100 kHz (S-8357/58)
J: VDD/VOUT separate type, fOSC = 250 kHz (S-8357/58)
G: VDD/VOUT separate type, fOSC = 300 kHz (S-8357/58)
P: VDD/VOUT separate type, fOSC = 600 kHz (S-8357/58)
K: Shutdown function + VDD/VOUT separate type, fOSC = 100 kHz (S-8355/56)
L: Shutdown function + VDD/VOUT separate type, fOSC = 250 kHz (S-8355/56)
M: Shutdown function + VDD/VOUT separate type, fOSC = 300 kHz (S-8355/56)
Q: Shutdown function + VDD/VOUT separate type, fOSC = 600 kHz (S-8355/56)
Control system
5 or 7: PWM control
6 or 8: PWM/PFM switching control
*1. Please refer to the taping specifications at the end of this document.
*2. Please refer to the product name list.
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
6 Seiko Instruments Inc.
4. Product Name List
4-1. S-8355 Series
Table 4
Model
Output Voltage
S-8355KxxMC Series S-8355LxxMC Series S-8355MxxMC Series S-8355MxxBD Series S-8355QxxBD Series
1.5 V S-8355Q15BD-OWA-TF
1.8 V S-8355K18MC-NAD-T2 S-8355M18MC-MCD-T2 S-8355M18BD-MCD-TF
2.0 V S-8355K20MC-NAF-T2 S-8355L20MC-NCF-T2 S-8355M20MC-MCF-T2
3.1 V S-8355K31MC-NAQ-T2 S-8355M31MC-MCQ-T2
3.3 V S-8355K33MC-NAS-T2
3.4 V S-8355M34MC-MCT-T2
5.0 V S-8355K50MC-NBJ-T2 S-8355M50MC-MDJ-T2
5.5 V S-8355M55MC-MDO-T2
Remark Please consult our sales person for products with an output voltage other than those specified above.
4-2. S-8356 Series
Table 5
Model
Output Voltage
S-8356KxxMC Series S-8356MxxMC Series S-8355MxxBD Series S-8356QxxMC Series
1.8 V S-8356K18MC-NED-T2 S-8356M18MC-MED-T2 S-8356M18BD-MED-TF
3.0 V S-8356M30MC-MEP-T2
3.3 V S-8356K33MC-NES-T2 S-8356Q33MC-OYS-T2
5.0 V S-8356K50MC-NFJ-T2 S-8356M50MC-MFJ-T2 S-8356Q50MC-OVJ-T2
Remark Please consult our sales person for products with an output voltage other than those
specified above.
4-3. S-8357 Series (1)
Table 6
Model
Output Voltage
S-8357BxxMC Series S-8357BxxMA Series S-8357BxxUA Series S-8357ExxMC Series S-8357FxxMC Series
2.0 V S-8357E20MC-NKF-T2
2.5 V
2.6 V S-8357B26MC-NIL-T2
3.0 V S-8357B30MC-NIP-T2 S-8357B30MA-NIP-T2
3.1 V
3.2 V S-8357F32MC-MGR-T2
3.3 V S-8357B33MC-NIS-T2 S-8357B33MA-NIS-T2 S-8357B33UA-NIS-T2 S-8357F33MC-MGS-T2
3.5 V
3.6 V S-8357B36MC-NIV-T2
4.8 V S-8357B48MC-NJH-T2 S-8357B48UA-NJH-T2
5.0 V S-8357B50MC-NJJ-T2 S-8357B50MA-NJJ-T2 S-8357B50UA-NJJ-T2 S-8357E50MC-NLJ-T2 S-8357F50MC-MHJ-T2
5.2 V S-8357B52MC-NJL-T2
5.4 V S-8357B54MC-NJN-T2
6.0 V S-8357B60MC-NJT-T2
Remark Please consult our sales person for products with an output voltage other than those specified above.
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
7
4-4. S-8357 Series (2)
Table 7
Model
Output Voltage S-8357GxxMC Series S-8357HxxMC Series S-8357JxxMC Series S-8357NxxMC Series
2.0 V
2.5 V S-8357J25MC-NOK-T2
2.6 V
3.0 V
3.1 V S-8357H31MC-NMQ-T2
3.2 V
3.3 V S-8357N33MC-O2S-T2
3.5 V S-8357H35MC-NMU-T2
3.6 V S-8357H36MC-NMV-T2
4.8 V
5.0 V S-8357G50MC-MJJ-T2 S-8357J50MC-NPJ-T2 S-8357N50MC-O3J-T2
5.2 V
5.4 V
6.0 V
Remark Please consult our sales person for products with an output voltage other than those
specified above.
4-5. S-8358 Series (1)
Table 8
Model
Output Voltage S-8358BxxMC Series S-8358BxxMA Series S-8358BxxUA Series S-8358ExxMC Series S-8358FxxMC Series
2.0 V S-8358E20MC-NSF-T2
2.5 V S-8358B25MC-NQK-T2
2.6 V S-8358B26MC-NQL-T2
3.0 V S-8358B30MC-NQP-T2
3.1 V S-8358B31MC-NQQ-T2
3.2 V S-8357B32MC-NQR-T2
3.3 V S-8358B33MC-NQS-T2 S-8358B33UA-NQS-T2 S-8358F33MC-MKS-T2
3.5 V S-8358B35MC-NQU-T2
3.6 V S-8358B36MC-NQV-T2
3.8 V S-8358B38MC-NQX-T2
5.0 V S-8358B50MC-NRJ-T2 S-8358B50MA-NRJ-T2 S-8358B50UA-NRJ-T2 S-8358E50MC-NTJ-T2 S-8358F50MC-MLJ-T2
5.3 V S-8358F53MC-MLM-T2
6.0 V S-8358B60MC-NRT-T2
Remark Please consult our sales person for products with an output voltage other than those specified above.
4-6. S-8358 Series (2)
Table 9
Model
Output Voltage S-8357GxxMC Series S-8357HxxMC Series S-8358JxxMC Series
2.0 V
2.5 V
2.6 V
3.0 V S-8358H30MC-NUP-T2
3.1 V
3.2 V
3.3 V S-8358H33MC-NUS-T2 S-8358J33MC-NWS-T2
3.5 V
3.6 V
3.8 V
5.0 V S-8358G50MC-MNJ-T2 S-8358H50MC-NVJ-T2 S-8358J50MC-NXJ-T2
5.3 V
6.0 V
Remark Please consult our sales person for products with an output
voltage other than those specified above.
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
8 Seiko Instruments Inc.
Pin Assignment
Table 10
Products: S-8357/58 Series B, H, F Types
(Without shutdown function, VDD/VOUT non-separate type)
Pin No. Pin Name Functions
1 VSS GND pin
2 VOUT Output voltage pin and IC power supply pin
3 EXT External transistor connection pin
Table 11
Products: S-8357/58 Series B, H, F Types
(Without shutdown function, VDD/VOUT non-separate type)
Pin No. Pin Name Functions
1 VOUT Output voltage pin and IC power supply pin
2 VSS GND pin
3 EXT External transistor connection pin
SOT-89-3
Top view
3
2
1
Figure 5
Figure 6
3
2
1
SOT23-3
Top view
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
9
Table 12
Products: S-8355/56 Series K, L, M, Q Types
(With shutdown function, VDD/VOUT separate type)
Pin No. Pin Name Functions
1 VOUT Output voltage pin
2 VDD IC power supply pin
3 ON/OFF
Shutdown pin
“H”: Normal operation (Step-up operation)
“L”
: Stop step-up (Whole circuit stop)
4 VSS GND pin
5 EXT External transistor connection pin
Table 13
Products: S-8357/58 Series B, H, F, N Types
(With shutdown function, VDD/VOUT non-separate type)
Pin No. Pin Name Functions
1 ON/OFF
Shutdown pin
“H”: Normal operation (Step-up operation)
“L”
: Stop step-up (Whole circuit stop)
2 VOUT Output voltage pin and IC power supply pin
3 NC*1 No connection
4 VSS GND pin
5 EXT External transistor connection pin
*1. The NC pin indicates electrically open.
Table 14
Products: S-8357/58 Series E, J, G, P Types
(Without shutdown function, VDD/VOUT separate type)
Pin No. Pin Name Functions
1 VOUT Output voltage pin
2 VDD IC power supply pin
3 NC*1 No connection
4 VSS GND pin
5 EXT External transistor connection pin
*1. The NC pin indicates electrically open.
SOT23-5
Top view
3
2
1
5 4
Figure 7
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
10 Seiko Instruments Inc.
Table 15
Products: S-8355/56 Series K, L, M, Q Types
(With shutdown function, VDD/VOUT separate type)
Pin No. Pin Name Functions
1 ON/OFF
Shutdown pin
“H”: Normal operation (Step-up operation)
“L”
: Stop step-up (Whole circuit stop)
2 VOUT Output voltage pin
3 VDD IC power supply pin
4 EXT External transistor connection pin
5 NC*1 No connection
6 VSS GND pin
*1. The NC pin indicates electrically open.
Table 16
Products: S-8357/58 Series B, H, F, N Types
(With shutdown function, VDD/VOUT non-separate type)
Pin No. Pin Name Functions
1 NC*1 No connection
2 ON/OFF
Shutdown pin
“H”: Normal operation (Step-up operation)
“L”
: Stop step-up (Whole circuit stop)
3 VOUT Output voltage pin and IC power supply pin
4 EXT External transistor connection pin
5 NC*1 No connection
6 VSS GND pin
*1. The NC pin indicates electrically open.
Table 17
Products: S-8357/58 Series E, J, G, P Types
(Without shutdown function, VDD/VOUT separate type)
Pin No. Pin Name Functions
1 NC*1 No connection
2 VOUT Output voltage pin
3 VDD IC power supply pin
4 EXT External transistor connection pin
5 NC*1 No connection
6 VSS GND pin
*1. The NC pin indicates electrically open.
6-Pin SNB(B)
Top view
3
2
1
6 4
5
Figure 8
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
11
Absolute Maximum Ratings
Table 18
(Unless otherwise specified: Ta = 25°C)
Parameter Symbol Ratings Unit
VOUT pin voltage VOUT VSS − 0.3 to VSS + 12
ON/OFF pin voltage*1 VON/OFF VSS − 0.3 to VSS + 12
VDD pin voltage*2 VDD V
SS − 0.3 to VSS + 12
B, H, F, N type VSS − 0.3 to VOUT + 0.3
EXT pin voltage VEXT
Others VSS − 0.3 to VDD + 0.3
V
EXT pin current IEXT ±80 mA
SOT-89-3 500
SOT-23-3 150
SOT-23-5 250
Power dissipation PD
6-Pin SNB(B) 90
mW
Operating temperature Topr −40 to +85
Storage temperature Tstg −40 to +125
°C
*1. With shutdown function
*2. For VDD/VOUT separate types
Caution The absolute maximum ratings are rated values exceeding which the product could suffer physical
damage. These values must therefore not be exceeded under any conditions.
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
12 Seiko Instruments Inc.
Electrical Characteristics
(1) 100 kHz types (S-835xBxx, S-835xExx, S-835xKxx)
Table 19
(Unless otherwise specified: Ta = 25°C)
Parameter Symbol Conditions Min. Typ. Max. Unit
Test
Circuit
Output voltage VOUT VOUT(S)
× 0.976
VOUT(S) VOUT(S)
× 1.024 V 2
Input voltage VIN − − 10
Operation start voltage VST1 IOUT = 1 mA − − 0.9
Oscillation start voltage VST2 No external parts, voltage applied to VOUT − − 0.8 1
Operation holding
voltage VHLD IOUT = 1 mA, Measured by decreasing VIN voltage
gradually 0.7 − −
2
S-835xx15 to 19 − 14.0 23.4
S-835xx20 to 29 − 19.7 32.9
S-835xx30 to 39 − 25.9 43.2
S-835xx40 to 49 − 32.6 54.4
S-835xx50 to 59 − 39.8 66.4
Current consumption 1 ISS1 VOUT = VOUT(S) × 0.95
S-835xx60 to 65 − 47.3 78.9
S-835xx15 to 19 − 5.6 11.1
S-835xx20 to 29 − 5.8 11.5
S-835xx30 to 39 − 5.9 11.8
S-835xx40 to 49 − 6.1 12.1
S-835xx50 to 59 − 6.3 12.5
Current consumption 2 ISS2 VOUT = VOUT(S) + 0.5
S-835xx60 to 65 − 6.4 12.8
Current consumption
during shutdown
(with shutdown function)
ISSS VON/OFF = 0 V
− − 0.5
µA
S-835xx15 to 19 −4.5 −8.9 −
S-835xx20 to 24 −6.2 −12.3 −
S-835xx25 to 29 −7.8 −15.7 −
S-835xx30 to 39 −10.3 −20.7 −
S-835xx40 to 49 −13.3 −26.7 −
S-835xx50 to 59 −16.1 −32.3 −
IEXTH VEXT = VOUT − 0.4
S-835xx60 to 65 −18.9 −37.7 −
S-835xx15 to 19 9.5 19.0 −
S-835xx20 to 24 12.6 25.2 −
S-835xx25 to 29 15.5 31.0 −
S-835xx30 to 39 19.2 38.5 −
S-835xx40 to 49 23.8 47.6 −
S-835xx50 to 59 27.4 54.8 −
EXT pin output current
IEXTL VEXT = 0.4 V
S-835xx60 to 65 30.3 60.6 −
mA
1
Line regulation ∆VOUT1 V
IN = VOUT(S) × 0.4 to × 0.6 − 30 60
Load regulation ∆VOUT2 I
OUT = 10 µA to VOUT(S)/50 × 1.25 − 30 60
mV
Output voltage
temperature coefficient
∆VOUT
∆Ta • VOUT
Ta = −40°C to +85°C − ±50 − ppm/°C
2
Oscillation frequency fOSC VOUT = VOUT(S) × 0.95 85 100 115
kHz
Max. duty ratio MaxDuty VOUT = VOUT(S) × 0.95 75 83 90
PWM/PFM switching
duty ratio (S-8356/58) PFMDuty VIN = VOUT(S) − 0.1 V, no load 10 15 24
%
VSH Measured the oscillation at EXT pin 0.75 − −
VSL1 When VOUT ≥ 1.5 V − − 0.3
Shutdown pin input
voltage (with shutdown
function) VSL2
Judged the stop of
oscillation at EXT pin When VOUT < 1.5 V − − 0.2
V
ISH Shutdown pin = VOUT(S) × 0.95 −0.1 − 0.1
Shutdown pin input
current (with shutdown
function) ISL Shutdown pin = 0 V −0.1 − 0.1
µA
1
Soft start time tSS 3.0 6.0 12.0
ms
Efficiency EFFI − 86 − %
2
External parts
- Coil: CDRH6D28-470 of Sumida Corporation
- Diode: RB461F (Schottky type) of Rohm Co., Ltd.
- Capacitor: F93 (16 V, 47 µF tantalum type) of Nichicon Corporation
- Transistor : CPH3210 of Sanyo Electric Co., Ltd.
- Base resistor (Rb): 1.0 kΩ
- Base capacitor (Cb): 2200 pF (ceramic type)
VIN = VOUT(S) × 0.6 applied, IOUT = VOUT(S)/50 Ω
Shutdown function built-in type: ON/OFF pin is connected to VOUT
V
DD/VOUT separate type: VDD pin is connected to VOUT pin
Remarks 1. VOUT(S) specified above is the set output voltage value, and VOUT is the typical value of the output voltage.
2. VDD/VOUT separate type:
Step-up operation is performed from VDD = 0.8 V.
However, 1.8 ≤ VDD ≤ 10 V is recommended to stabilize the output voltage and oscillation frequency.
(VDD ≥ 1.8 V must be applied for products with a set value of less than 1.9 V.)
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
13
(2) 250 kHz types (S-835xHxx, S-835xJxx, S-835xLxx)
Table 20
(Unless otherwise specified: Ta = 25°C)
Parameter Symbol Conditions Min. Typ. Max. Unit
Test
Circuit
Output voltage VOUT VOUT(S)
× 0.976 VOUT(S) VOUT(S)
× 1.024 V 2
Input voltage VIN − − 10
Operation start voltage VST1 IOUT = 1 mA − − 0.9
Oscillation start voltage VST2 No external parts, voltage applied to VOUT − − 0.8 1
Operation holding
voltage VHLD IOUT = 1 mA, Measured by decreasing VIN voltage
gradually 0.7 − −
2
S-835xx15 to 19 − 28.9 48.2
S-835xx20 to 29 − 42.7 71.1
S-835xx30 to 39 − 58.0 96.7
S-835xx40 to 49 − 74.5 124.1
S-835xx50 to 59 − 92.0 153.4
Current consumption 1 ISS1 VOUT = VOUT(S) × 0.95
S-835xx60 to 65 − 110.5 184.2
S-835xx15 to 19 − 8.7 17.3
S-835xx20 to 29 − 8.8 17.6
S-835xx30 to 39 − 9.0 18.0
S-835xx40 to 49 − 9.2 18.3
S-835xx50 to 59 − 9.3 18.6
Current consumption 2 ISS2 VOUT = VOUT(S) + 0.5
S-835xx60 to 65 − 9.5 19.0
Current consumption
during shutdown
(with shutdown function)
ISSS VON/OFF = 0 V − − 0.5
µA
S-835xx15 to 19 −4.5 −8.9 −
S-835xx20 to 24 −6.2 −12.3 −
S-835xx25 to 29 −7.8 −15.7 −
S-835xx30 to 39 −10.3 −20.7 −
S-835xx40 to 49 −13.3 −26.7 −
S-835xx50 to 59 −16.1 −32.3 −
IEXTH VEXT = VOUT − 0.4
S-835xx60 to 65 −18.9 −37.7 −
S-835xx15 to 19 9.5 19.0 −
S-835xx20 to 24 12.6 25.2 −
S-835xx25 to 29 15.5 31.0 −
S-835xx30 to 39 19.2 38.5 −
S-835xx40 to 49 23.8 47.6 −
S-835xx50 to 59 27.4 54.8 −
EXT pin output current
IEXTL VEXT = 0.4 V
S-835xx60 to 65 30.3 60.6 −
mA
1
Line regulation ∆VOUT1 V
IN = VOUT(S) × 0.4 to × 0.6 − 30 60
Load regulation ∆VOUT2 I
OUT = 10 µA to VOUT(S)/50 × 1.25 − 30 60
mV
Output voltage
temperature coefficient
∆VOUT
∆Ta • VOUT
Ta = −40°C to +85°C − ±50 − ppm/°C
2
Oscillation frequency fOSC VOUT = VOUT(S) × 0.95 212.5 250 287.5
kHz
Max. duty ratio MaxDuty VOUT = VOUT(S) × 0.95 70 78 85
PWM/PFM switching
duty ratio (S-8356/58) PFMDuty VIN = VOUT(S) − 0.1 V, no load 10 15 24
%
VSH Measured the oscillation at EXT pin 0.75 − −
VSL1 When VOUT ≥ 1.5 V − − 0.3
Shutdown pin input
voltage (with shutdown
function) VSL2
Judged the stop of
oscillation at EXT pin When VOUT < 1.5 V − − 0.2
V
ISH Shutdown pin = VOUT(S) × 0.95 −0.1 − 0.1
Shutdown pin input
current (with shutdown
function) ISL Shutdown pin = 0 V −0.1 − 0.1
µA
1
Soft start time tSS 1.5 3.0 6.0
ms
Efficiency EFFI − 85 − %
2
External parts
- Coil: CDRH6D28-220 of Sumida Corporation
- Diode: RB461F (Schottky type) of Rohm Co., Ltd.
- Capacitor: F93 (16 V, 47 µF tantalum type) of Nichicon Corporation
- Transistor : CPH3210 of Sanyo Electric Co., Ltd.
- Base resistor (Rb): 1.0 kΩ
- Base capacitor (Cb): 2200 pF (ceramic type)
V
IN = VOUT(S) × 0.6 applied, IOUT = VOUT(S)/50 Ω
Shutdown function built-in type: ON/OFF pin is connected to VOUT
V
DD/VOUT separate type: VDD pin is connected to VOUT pin
Remarks 1. VOUT(S) specified above is the set output voltage value, and VOUT is the typical value of the output voltage.
2. VDD/VOUT separate type:
Step-up operation is performed from VDD = 0.8 V.
However, 1.8 ≤ VDD ≤ 10 V is recommended to stabilize the output voltage and oscillation frequency.
(VDD ≥ 1.8 V must be applied for products with a set value of less than 1.9 V.)
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
14 Seiko Instruments Inc.
(3) 300 kHz types (S-835xFxx, S-835xGxx, S-835xMxx)
Table 21
(Unless otherwise specified: Ta = 25°C)
Parameter Symbol Conditions Min. Typ. Max. Unit
Test
Circuit
Output voltage VOUT VOUT(S)
× 0.976
VOUT(S) V
OUT(S)
× 1.024 V 2
Input voltage VIN − − 10
Operation start voltage VST1 IOUT = 1 mA − − 0.9
Oscillation start voltage VST2 No external parts, voltage applied to VOUT − − 0.8 1
Operation holding
voltage VHLD IOUT = 1 mA, Measured by decreasing VIN voltage
gradually 0.7 − −
2
S-835xx15 to 19 − 33.8 56.4
S-835xx20 to 29 − 50.3 83.9
S-835xx30 to 39 − 68.6 114.4
S-835xx40 to 49 − 88.4 147.4
S-835xx50 to 59 − 109.4 182.4
Current consumption 1 ISS1 VOUT = VOUT(S) × 0.95
S-835xx60 to 65 − 131.6 219.3
S-835xx15 to 19 − 9.7 19.4
S-835xx20 to 29 − 9.9 19.7
S-835xx30 to 39 − 10.0 20.0
S-835xx40 to 49 − 10.2 20.4
S-835xx50 to 59 − 10.4 20.7
Current consumption 2 ISS2 VOUT = VOUT(S) + 0.5
S-835xx60 to 65 − 10.5 21.0
Current consumption
during shutdown
(with shutdown function)
ISSS VON/OFF = 0 V − − 0.5
µA
S-835xx15 to 19 −4.5 −8.9 −
S-835xx20 to 24 −6.2 −12.3 −
S-835xx25 to 29 −7.8 −15.7 −
S-835xx30 to 39 −10.3 −20.7 −
S-835xx40 to 49 −13.3 −26.7 −
S-835xx50 to 59 −16.1 −32.3 −
IEXTH VEXT = VOUT − 0.4
S-835xx60 to 65 −18.9 −37.7 −
S-835xx15 to 19 9.5 19.0 −
S-835xx20 to 24 12.6 25.2 −
S-835xx25 to 29 15.5 31.0 −
S-835xx30 to 39 19.2 38.5 −
S-835xx40 to 49 23.8 47.6 −
S-835xx50 to 59 27.4 54.8 −
EXT pin output current
IEXTL VEXT = 0.4 V
S-835xx60 to 65 30.3 60.6 −
mA
1
Line regulation ∆VOUT1 V
IN = VOUT(S) × 0.4 to × 0.6 − 30 60
Load regulation ∆VOUT2 I
OUT = 10 µA to VOUT(S)/50 × 1.25 − 30 60
mV
Output voltage
temperature coefficient
∆VOUT
∆Ta • VOUT
Ta = − 40°C to + 85°C − ±50 − ppm/°C
2
Oscillation frequency fOSC VOUT = VOUT(S) × 0.95 255 300 345
kHz
Max. duty ratio MaxDuty VOUT = VOUT(S) × 0.95 70 78 85
PWM/PFM switching
duty ratio (S-8356/58) PFMDuty VIN = VOUT(S) − 0.1 V, no load 10 15 24
%
VSH Measured the oscillation at EXT pin 0.75 − −
VSL1 When VOUT ≥ 1.5 V − − 0.3
Shutdown pin input
voltage (with shutdown
function) VSL2
Judged the stop of
oscillation at EXT pin When VOUT < 1.5 V − − 0.2
V
ISH Shutdown pin = VOUT(S) × 0.95 −0.1 − 0.1
Shutdown pin input
current (with shutdown
function) ISL Shutdown pin = 0 V −0.1 − 0.1
µA
1
Soft start time tSS 1.5 3.0 6.0 ms
Efficiency EFFI − 85 − %
2
External parts
- Coil: CDRH6D28-220 of Sumida Corporation
- Diode: RB461F (Schottky type) of Rohm Co., Ltd.
- Capacitor: F93 (16 V, 47 µF tantalum type) of Nichicon Corporation
- Transistor : CPH3210 of Sanyo Electric Co., Ltd.
- Base resistor (Rb): 1.0 kΩ
- Base capacitor (Cb): 2200 pF (ceramic type)
V
IN = VOUT(S) × 0.6 applied, IOUT = VOUT(S)/50 Ω
Shutdown function built-in type: ON/OFF pin is connected to VOUT
V
DD/VOUT separate type: VDD pin is connected to VOUT pin
Remarks 1. VOUT(S) specified above is the set output voltage value, and VOUT is the typical value of the output voltage.
2. VDD/VOUT separate type:
Step-up operation is performed from VDD = 0.8 V.
However, 1.8 ≤ VDD ≤ 10 V is recommended to stabilize the output voltage and oscillation frequency.
(VDD ≥ 1.8 V must be applied for products with a set value of less than 1.9 V.)
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
15
(4) 600 kHz types (S-835xNxx)
Table 22
(Unless otherwise specified: Ta = 25°C)
Parameter Symbol Conditions Min. Typ. Max. Unit
Test
Circuit
Output voltage VOUT VOUT(S)
× 0.976
VOUT(S) V
OUT(S)
× 1.024 V 2
Input voltage VIN − − 10
Operation start voltage VST1 IOUT = 1 mA − − 0.9
Oscillation start voltage VST2 No external parts, voltage applied to VOUT − − 0.8 1
Operation holding
voltage VHLD IOUT = 1 mA, Measured by decreasing VIN voltage
gradually 0.7 − −
2
S-835xx15 to 19 − 63.6 105.9
S-835xx20 to 29 − 96.4 160.6
S-835xx30 to 39 − 132.8 221.3
S-835xx40 to 49 − 172.2 286.9
S-835xx50 to 59 − 214.0 356.7
Current consumption 1 ISS1 VOUT = VOUT(S) × 0.95
S-835xx60 to 65 − 240.2 400.3
S-835xx15 to 19 − 15.9 31.8
S-835xx20 to 29 − 16.1 32.1
S-835xx30 to 39 − 16.2 32.4
S-835xx40 to 49 − 16.4 32.8
S-835xx50 to 59 − 16.6 33.1
Current consumption 2 ISS2 VOUT = VOUT(S) + 0.5
S-835xx60 to 65 − 16.7 33.3
Current consumption
during shutdown ISSS VON/OFF = 0 V − − 0.5
µA
S-835xx15 to 19 −4.5 −8.9 −
S-835xx20 to 24 −6.2 −12.3 −
S-835xx25 to 29 −7.8 −15.7 −
S-835xx30 to 39 −10.3 −20.7 −
S-835xx40 to 49 −13.3 −26.7 −
S-835xx50 to 59 −16.1 −32.3 −
IEXTH VEXT = VOUT − 0.4
S-835xx60 to 65 −18.9 −37.7 −
S-835xx15 to 19 9.5 19.0 −
S-835xx20 to 24 12.6 25.2 −
S-835xx25 to 29 15.5 31.0 −
S-835xx30 to 39 19.2 38.5 −
S-835xx40 to 49 23.8 47.6 −
S-835xx50 to 59 27.4 54.8 −
EXT pin output current
IEXTL VEXT = 0.4 V
S-835xx60 to 65 30.3 60.6 −
mA
1
Line regulation ∆VOUT1 V
IN = VOUT(S) × 0.4 to × 0.6 − 30 60
Load regulation ∆VOUT2 I
OUT = 10 µA to VOUT(S)/50 × 1.25 − 30 60
mV
Output voltage
temperature coefficient
∆VOUT
∆Ta • VOUT
Ta = −40°C to +85°C − ±50 − ppm/°C
2
Oscillation frequency fOSC VOUT = VOUT(S) × 0.95 510 600 690
kHz
Max. duty ratio MaxDuty VOUT = VOUT(S) × 0.95 65 78 85
PWM/PFM switching
duty ratio (S-8356/58) PFMDuty VIN = VOUT(S) − 0.1 V, no load 10 15 24
%
VSH Measured the oscillation at EXT pin 0.75 − −
VSL1 When VOUT ≥ 1.5 V − − 0.3
Shutdown pin input
voltage VSL2
Judged the stop of
oscillation at EXT pin When VOUT < 1.5 V − − 0.2
V
ISH Shutdown pin = VOUT(S) × 0.95 −0.1 − 0.1
Shutdown pin input
current ISL Shutdown pin = 0 V −0.1 − 0.1
µA
1
Soft start time tSS 1.5 3.0 6.0 ms
Efficiency EFFI − 85 − %
2
External parts
- Coil: CDRH6D28-100 of Sumida Corporation
- Diode: RB461F (Schottky type) of Rohm Co., Ltd.
- Capacitor: F93 (16 V, 47 µF tantalum type) of Nichicon Corporation
- Transistor: CPH3210 of Sanyo Electric Co., Ltd.
- Base resistor (Rb): 1.0 kΩ
- Base capacitor (Cb): 2200 pF (ceramic type)
VIN = VOUT(S) × 0.6 applied, IOUT = VOUT(S)/50 Ω, ON/OFF = VOUT
Remark VOUT(S) specified above is the set output voltage value, and VOUT is the typical value of the output voltage.
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
16 Seiko Instruments Inc.
(5) 600 kHz types (S-835xPxx, S-835xQxx)
Table 23
(Unless otherwise specified: Ta = 25°C)
Parameter Symbol Conditions Min. Typ. Max. Unit
Test
Circuit
Output voltage VOUT VOUT(S)
× 0.976
VOUT(S) V
OUT(S)
× 1.024 V 4
Input voltage VIN − − 10
Operation start voltage VST1 IOUT = 1 mA − − 0.9
Oscillation start voltage VST2 No external parts, voltage applied to VDD − − 0.8 3
Operation holding
voltage VHLD IOUT = 1 mA, Measured by decreasing VIN voltage
gradually 0.7 − −
4
Current consumption 1 ISS1 VDD = 3.3 V − 132.8 221.3
Current consumption 2 ISS2 VDD = 3.3 V − 16.2 32.4
Current consumption
during shutdown
(with shutdown function)
ISSS VON/OFF = 0 V − − 0.5
µA
IEXTH VDD = 3.3 V −10.3 −20.7 −
EXT pin output current
IEXTL VDD = 3.3 V 19.2 38.5 −
mA
3
Line regulation ∆VOUT1 V
IN = VOUT(S) × 0.4 to × 0.6 − 30 60
Load regulation ∆VOUT2 I
OUT = 10 µA to VOUT(S)/50 × 1.25 − 30 60
mV
Output voltage
temperature coefficient
∆VOUT
∆Ta • VOUT
Ta = −40°C to +85°C − ±50 − ppm/°C
4
Oscillation frequency fOSC VDD = 3.3 V 510 600 690
kHz
Max. duty ratio MaxDuty VDD = 3.3 V 65 78 85
PWM/PFM switching
duty ratio (S-8356/58) PFMDuty VIN = VOUT(S) − 0.1 V, no load 10 15 24
%
VSH Measured the oscillation at EXT pin 0.75 − −
VSL1 When VOUT ≥ 1.5 V − − 0.3
Shutdown pin input
voltage
(with shutdown function) VSL2
Judged the stop of
oscillation at EXT pin When VOUT < 1.5 V − − 0.2
V
ISH Shutdown pin = VOUT(S) × 0.95 −0.1 − 0.1
Shutdown pin input
current
(with shutdown function) ISL Shutdown pin = 0 V −0.1 − 0.1
µA
3
Soft start time tSS 1.5 3.0 6.0 ms
Efficiency EFFI − 85 − %
4
External parts
- Coil: CDRH6D28-100 of Sumida Corporation
- Diode: RB461F(Schottky type) of Rohm Co., Ltd.
- Capacitor: F93 (16 V, 47 µF tantalum type) of Nichicon Corporation
- Transistor: CPH3210 of Sanyo Electric Co., Ltd.
- Base resistor (Rb): 1.0 kΩ
- Base capacitor (Cb): 2200 pF (ceramic type)
V
IN = VOUT(S) × 0.6 applied, IOUT = VOUT(S)/50 Ω, ON/OFF = 3.3 V
Remarks 1. VOUT(S) specified above is the set output voltage value, and VOUT is the typical value of the output voltage.
2. VDD/VOUT separate type:
Step-up operation is performed from VDD = 0.8 V.
However, 1.8 ≤ VDD ≤ 10 V is recommended to stabilize the output voltage and oscillation frequency.
(VDD ≥ 1.8 V must be applied for products with a set value of less than 1.9 V.)
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
17
Test Circuits
1.
Figure 9
VSS
VOUT
(VDD)
EXT
(ON/OFF)
Oscilloscope
0.1
µ
F
−
+
A
2.
0.1
µ
F
V
−
+
−
+
(VDD)
VSS
VOUT
(ON/OFF)
EXT
Rb
Cb
Figure 10
3.
Figure 11
0.1 µF
VSS
VOUT
(VDD)
EXT
(ON/OFF)
Oscilloscope
−
+
A
4.
Figure 12
0.1
µ
F
V
−
+
−
+
(VDD)
VSS
VOUT
(ON/OFF)
EXT
Rb
Cb
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
18 Seiko Instruments Inc.
Operation
1. Switching control types
1-1. PWM control (S-8355/57 Series)
The S-8355/57 Series is a DC-DC converter using a pulse width modulation method (PWM) and
features a low current consumption.
In conventional PFM DC-DC converters, pulses are skipped when the output load current is low,
causing a fluctuation in the ripple frequency of the output voltage, resulting in an increase in the ripple
voltage.
In S-8355/57 Series, the switching frequency does not change, although the pulse width changes from
0% to 83% (78% for F, G, H, J, L, M, N, P, Q types) corresponding to each load current. The ripple
voltage generated from switching can thus be removed easily through a filter because the switching
frequency is constant.
1-2. PWM/PFM switching control (S-8356/58 Series)
S-8356/58 Series is a DC-DC converter that automatically switches between a pulse width modulation
method (PWM) and a pulse frequency modulation method (PFM), depending on the load current, and
features a low current consumption. This series is a particularly highly efficient DC-DC converter at an
output current of around 100 µA.
In conventional constant-duty PFM DC-DC converters, pulses are skipped when the output load
current is low, causing a fluctuation in the ripple frequency of the output voltage, resulting in an increase
in the ripple voltage. The S-8356/58 Series operates under PWM control with the pulse width duty
changing from 15% to 83% (78% for F, G, H, J, L, M, N, P, Q types) in a high output load current area.
On the other hand, the S-8356/58 Series operates under PFM control with the pulse width duty fixed at
15% in a low output load current area, and pulses are skipped when the low output load current is low
according to the load current and output to the switching transistor. The oscillation circuit thus oscillates
intermittently so that the resultant lower self-consumption can prevent a reduction in the efficiency at a
low load current. The switching point from PWM control to PFM control depends on the external
devices (coil, diode, etc.), input voltage and output voltage.
2. Soft start function
For this IC, the built-in soft start circuit controls the rush current and overshoot of the output voltage
when powering on or when the ON/OFF pin is switched to the “H” level.
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
19
3. Shutdown pin (Only for SOT-23-5 package products of B, H, F, K, L, M, N, and Q types and for 6-Pin
SNB(B) package products.)
Stops or starts step-up operation.
Switching the shutdown pin to the “L” level stops operation of all the internal circuits and reduces the
current consumption significantly.
DO NOT use the shutdown pin in a floating state because it has the structure shown in Figure 13 and is
not pulled up or pulled down internally. DO NOT apply voltage of between 0.3 V and 0.75 V to the
shutdown pin because applying such a voltage increases the current consumption. If the shutdown pin
is not used, connect it to the VOUT (VDD for K, L, M, Q types) pin.
The shutdown pin does not have hysteresis.
Table 24
Shutdown Pin CR Oscillation Circuit Output Voltage
“H” Operation Fixed
“L” Stop ≅ VIN
*1
*1. Voltage obtained by subtracting the voltage drop due to DC resistance of the inductor and
the diode forward voltage from VIN.
Figure 13 Shutdown Pin Structure
V
VSS
(VDD for K, L , M, Q types)
ON/OFF
VOUT
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
20 Seiko Instruments Inc.
4. Operation
The following are basic equations [(1) through (7)] of the step-up switching regulator (refer to Figure 14).
CL
M1
D
VOUT
CONT
VIN
L
+
−
EXT
VSS
Figure 14 Step-up Switching Regulator Circuit for Basic Equations
Voltage at the CONT pin at the moment M1 is turned ON (current IL flowing through L is zero), VA:
Change in IL over time:
Integration of the above equation :
IL flows while M1 is ON (tON). The time of tON is determined by the oscillation frequency of OSC.
Peak current (IPK) after tON:
The energy stored in L is represented by • • L (IPK)2 .
When M1 is turned OFF (tOFF), the energy stored in L is transmitted through a diode to the output capacitor.
Then, reverse voltage (VL) is generated:
The voltage at the CONT pin rises only by VOUT + VD.
Change in the current (IL) flowing through the diode into VOUT during tOFF:
Integration of the above equation is as follows:
= = ........................................................... (2)
I
L = • t ....................................................................... (3)
I
PK = • tON .................................................................. (4)
= = ...................................................... (6)
I
L = IPK − • t ..................................................... (7)
....................................................................... (5)
........................................................................................... (1)
*1. VS: Non-saturated voltage of M1
VA = VS
*1
dIL
dt
VL
L
VIN − VS
L
VIN − VS
L
VIN − VS
L
dIL
dt
VL
L
VOUT + VD − VIN
L
L
VOUT + VD − VIN
VL = (VOUT + VD
*2) − VIN
*2. VD: Diode forward voltage
1
2
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
21
During tON, the energy is stored in L and is not transmitted to VOUT. When receiving output current (IOUT)
from VOUT, the energy of the capacitor (CL) is consumed. As a result, the pin voltage of CL is reduced, and
goes to the lowest level after M1 is turned ON (tON). When M1 is turned OFF, the energy stored in L is
transmitted through the diode to CL, and the voltage of CL rises drastically. VOUT is a time function indicating
the maximum value (ripple voltage: VP−P) when the current flowing through into VOUT and load current (IOUT)
match.
Next, the ripple voltage is determined as follows:
IOUT vs t1 (time) from when M1 is turned OFF (after tON) to when VOUT reaches the maximum level:
When M1 is turned ON (after tOFF), IL = 0 (when the energy of the inductor is completely transmitted):
Based on equation (7),
When substituting equation (10) for equation (9),
Electric charge ∆Q1 which is charged in CL during t1 :
When substituting equation (12) for equation (9):
A rise in voltage (VP−P) due to ∆Q 1:
When taking into consideration IOUT to be consumed during t1 and ESR*1 of CL:
*1. Equivalent Series Resistance
= ............................................................................................(10)
t
1 = tOFF − • tOFF ................................................................................................... (11)
∆Q1 = IPK − (IPK − IOUT) • t1 = • t1 .............................................................. (13)
V
P-P = = • • t1 + • RESR − ............... (15)
I
OUT = IPK − • t1
.................................................................................. (8)
∴ t
1 = (IPK − IOUT) • .................................................................................. (9)
V
P-P = = • • t1 .................................................................... (14)
VOUT + VD − VIN
L
IPK
tOFF
IPK
IOUT
VOUT + VD − VIN
L
VOUT + VD − VIN
L
∆Q1 = ∫ ILdt = IPK • ∫ dt − • ∫ tdt = IPK • t1 − • t1
2 (12)
VOUT + VD − VIN
L 2
1
t1
0
VOUT + VD − VIN
L
0
t1
0
t1
2
1
2
IPK + IOUT
CL
∆Q1
CL
1
2
IPK + IOUT
CL
∆Q1
CL
1
2
IPK + IOUT
CL
IOUT • t1
2
IPK + IOUT
…...…..
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
22 Seiko Instruments Inc.
When substituting equation (11) for equation (15):
Therefore to reduce the ripple voltage, it is important that the capacitor connected to the output pin has a
large capacity and a small ESR.
V
P-P = • + • RESR .................................................. (16)
2IPK
(IPK − IOUT)
2
CL
tOFF
2
IPK + IOUT
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
23
External Parts Selection
The relationship between the major characteristics of the step-up circuit and the characteristics parameters of
the external parts are shown in Figure 15.
For higher efficiency?
For larger output current?
Operation efficiency Stand-by efficiency
For smaller ripple voltage?
Figure 15 Relationship Between Major Characteristics of Step-up Circuit and External Parts
Smaller inductance Larger inductance
Smaller DC resistance of inductor
Larger output capacitance
With MOS FET, smaller
input capacitance
With MOS FET, smaller ON resistance
With bipolar transistor, smaller external
resistance Rb
With bipolar transistor,
larger external resistance
R
b
Larger output capacitance
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
24 Seiko Instruments Inc.
1. Inductor
The inductance has a strong influence on the maximum output current IOUT and efficiency η.
Figure 16 shows the relationship between the IOUT and η dependency on L of S-8355/56/57/58.
The peak current (IPK) increases by decreasing L and the stability of the circuit improves and IOUT increases.
If L is decreased further, the efficiency falls and if the current drive capability is insufficient, IOUT decreases.
(Based on the current drive capability of external switching transistor.)
The loss of IPK by the switching transistor decreases by increasing L and the efficiency becomes maximum
at a certain L value. Further increasing L decreases the efficiency due to the loss of the DC resistance of
the coil. IOUT also decreases.
If the oscillation frequency is higher, a smaller L value can be chosen, making the coil smaller.
The recommended inductances are a 22 to 100 µH inductor for B, E, and K types, a 4.7 to 47 µH inductor
for F, G, H, J, L, and M types, 3.0 to 22 µH inductor for N, P, Q, types.
Choose an inductor so that IPK does not exceed the allowable current. Exceeding the allowable current of
the inductor causes magnetic saturation, much lower efficiency and destruction of the IC chip due to a
large current.
IPK in discontinuous mode is calculated by the following equation:
f
OSC = Oscillation frequency, VD ≅ 0.4 V.
2. Diode
Use an external diode that meets the following requirements:
• Low forward voltage: (VF < 0.3 V)
• High switching speed: (50 ns max.)
• Reverse voltage: VOUT + VF or more
• Rated current: IPK or more
IPK =
2 IOUT (VOUT + VD − VIN)
fOSC • L (A) ..............................(17)
CDRH6D28 VOUT = 5.0 V, VIN = 3.0 V
F, G, H, J, L, M Type
Recommended range
IOUT
η
4.7 47
Efficiency
decreases
IOUT decreases
IPK increases
Coil size:
smaller
Efficiency
decreases
IOUT
decreases
IPK decreases
Coil size:
bigger
L (µH)
Figure 16 L-IOUT and η
ηη
η Characteristics
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
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Seiko Instruments Inc.
25
3. Capacitor (CIN, CL)
A capacitor on the input side (CIN) improves the efficiency by reducing the power impedance and stabilizing
the input current. Select a CIN value according to the impedance of the power supply used.
A capacitor on the output side (CL) is used for smoothing the output voltage. For step-up types, the output
voltage flows intermittently to the load current, so step-up types need a larger capacitance than step-down
types. Therefore, select an appropriate capacitor in accordance with the ripple voltage, which increases in
case of a higher output voltage or a higher load current. The capacitor value should be 10 µF minimum.
Select an appropriate capacitor taking into consideration the ESR (Equivalent Series Resistance) for
stable output voltage. A stable voltage range in this IC depends on the ESR. Although the inductance (L) is
also a factor, an ESR of 30 mΩ to 500 mΩ draws out the characteristics. However, the best ESR may
depend on L, the capacitance, the wiring and the application (output load). Therefore, fully evaluate the
ESR under actual conditions to determine the best value.
“2 Ceramic capacitor” of “Application Circuits” shows an example of a circuit that uses a ceramic capacitor
and external resistance (ESR) for reference.
4. External transistor
A bipolar (NPN) transistor or an enhancement (N-channel) MOS FET transistor can be used as the
external transistor.
4.1 Bipolar (NPN) transistor
A circuit example using the CPH3210 (hFE = 200 to 560) from Sanyo Electric Co., Ltd. as the bipolar
transistor (NPN) is shown in Figure 19 of “Standard Circuits”. The hFE value and the Rb value
determine the driving capacity when the output current is increased using a bipolar transistor. A
peripheral circuit example of the transistor is shown in Figure 17.
1 kΩ is recommended for Rb. Rb is determined by the following calculation. Calculate the necessary
base current (Ib) from the bipolar transistor hFE using Ib =
A small Rb increases the output current, but the efficiency decreases. The current flows pulsating and
there is a voltage drop due to wiring resistance in the actual circuit, therefore the optimum Rb value
should be determined by experiment.
A speed-up capacitor (Cb) connected in parallel with the Rb resistance as shown in Figure 17
decreases the switching loss and improves the efficiency.
Cb is calculated from the following equation:
However, in practice, the optimum Cb value also varies depending on the characteristics of the bipolar
transistor employed. Therefore, determine the optimum value by experiment.
VOUT
IPK
Nch
Pch
Rb
EXT
Cb
2200 pF
1 kΩ
(VDD for E, G, J, K, L, M, P, Q types)
2π • Rb • fOSC • 0.7
1
Cb ≤
for E, G, J, K, L, M, P, and Q types)
(
Rb = VDD − 0.7
Ib | IEXTH |
0.4
Rb = | IEXTH |
0.4
Ib
VOUT − 0.7
IPK
hFE.
Figure 17 External Transistor Peripheral
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26 Seiko Instruments Inc.
4.2 Enhancement MOS FET type
Figure 18 is a circuit example using a MOS FET transistor (N-channel).
An N-channel power MOS FET should be used for the MOS FET. Because the gate voltage and
current of the external power MOS FET are supplied from the stepped-up output voltage VOUT, the
MOS FET is driven more effectively.
Depending on the MOS FET you use in your device, there is a chance of a current overrun at power
ON. Thoroughly test all settings with your device before deciding on which one to use. Also, try to use
a MOS FET with an input capacitance of 700 pF or less.
Since the ON resistor of the MOS FET might depend on the difference between the output voltage
VOUT and the threshold voltage of the MOS FET, and affect the output current as well as the efficiency,
the threshold voltage should be low.
When the output voltage is low, the circuit operates only when the MOS FET has a threshold voltage
lower than the output voltage.
Figure 18 Circuit Example Using MOS FET
VOUT
EXT
VOUT
(ON / OFF)
VSS
(VDD)
−
+
−
+
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
27
5. VDD/VOUT separate types (E, G, J, K, L, M, P, and Q types)
The E, G, J, K, L, M, P, and Q types are ideal for the following applications because the power pin for the IC
chip and the VOUT pin for the output voltage are separated:
(1) When changing the output voltage by external resistance.
(2) When outputting a high voltage such as +15 V or + 20 V.
Choose the products in Table 25 according to applications (1) and (2) above.
Table 25
Output Voltage VCC 1.8 V ≤ VCC < 5 V 5 V ≤ VCC Reference Circuit
S-835xx18 Yes Yes Application circuit 1 (Figure 26)
S-835xx50 Yes Application circuit 1 (Figure 26)
Connection to VDD pin VIN or VCC V
IN
Cautions 1. This IC starts a step-up operation at VDD =
==
= 0.8 V, but set 1.8 ≤
≤≤
≤ VDD ≤
≤≤
≤ 10 V to stabilize the
output voltage and frequency of the oscillator.
(Input a voltage of 1.8 V or more at the VDD pin for all products with a setting less
than 1.9 V.)
An input voltage of 1.8 V or more at the VDD pin allows connection of the VDD pin to
either the input power pin VIN or output power pin VOUT.
2. Choose external resistors RA and RB so as to not affect the output voltage,
considering that there is impedance between the VOUT and VSS pins in the IC
chip.
The internal resistance between the VOUT and VSS pins is as follows:
(1) S-835xx18 →
→→
→ 2.1 MΩ
ΩΩ
Ω to 14.8 MΩ
ΩΩ
Ω
(2) S-835xx20 →
→→
→ 1.4 MΩ
ΩΩ
Ω to 14.8 MΩ
ΩΩ
Ω
(2) S-835xx30 →
→→
→ 1.4 MΩ
ΩΩ
Ω to 14.2 MΩ
ΩΩ
Ω
(3) S-835xx50 →
→→
→ 1.4 MΩ
ΩΩ
Ω to 12.1 MΩ
ΩΩ
Ω
3. Attach a capacitor (CC) in parallel to the RA resistance when an unstable event such
as oscillation of the output voltage occurs. Calculate CC using the following
equation:
2 •
••
• π
ππ
π •
••
• RA •
••
• 20 kHz
1
CC(F) =
==
=
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
28 Seiko Instruments Inc.
(1) S-8357BxxMA, S-8357BxxUA, S-8358BxxMA, S-8358BxxUA
(2) S-8357BxxMC, S-8357FxxMC/BD, S-8357HxxMC/BD, S-8357NxxMC/BD
S-8358BxxMC, S-8358FxxMC/BD, S-8358HxxMC/BD, S-8358NxxMC/BD
Standard Circuits
(3) S-8357ExxMC, S-8357GxxMC/BD, S-8357JxxMC/BD, S-8357PxxMC/BD
S-8358ExxMC, S-8358GxxMC/BD, S-8358JxxMC/BD, S-8358PxxMC/BD
SD
CL
VIN
L
1 kΩ
VOUT
VSS
EXT
−
+
−
+
−
+
PWM or PWM
/PFM switching
control circuit
Soft start
built-in reference
p
ower su
pp
l
y
Phase
compensation
circuit
Oscillation circuit
IC internal
power supply
2200 pF
CIN
Remark The power supply for the IC
chip is from the VOUT pin.
Figure 19
Figure 20
SD
Remark The power supply for
the IC chip is from the
VOUT pin.
−
+
−
+
1 kΩ
VIN
L
VOUT
VSS
EXT
−
+
2200 pF
CIN
ON/OFF
CL
PWM or PWM
/PFM switching
control circuit
Soft start
built-in reference
p
ower su
pp
l
y
Phase
compensation
circuit
Oscillation circuit
IC internal
power supply
Figure 21
Remark The power supply for the IC
chip is from the VDD pin.
−
+
−
+
−
+
CL
L
SD
1 kΩ
VIN
VOUT
VSS
EXT
2200 pF
CIN
VDD
PWM or PWM
/PFM switching
control circuit
Soft start
built-in reference
p
ower su
pp
l
y
Phase
compensation
circuit
Oscillation circuit IC
internal
power
supply
RA
RB
CC
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
29
(4) S-8357ExxMC, S-8357GxxMC/BD, S-8357JxxMC/BD
S-8358ExxMC, S-8358GxxMC/BD, S-8358JxxMC/BD
(5) S-8355KxxMC/BD, S-8355LxxMC/BD, S-8355MxxMC/BD, S-8355QxxMC/BD
S-8356KxxMC/BD, S-8356LxxMC/BD, S-8356MxxMC/BD, S-8356QxxMC/BD
(6) S-8355KxxMC/BD, S-8355LxxMC/BD, S-8355MxxMC/BD
S-8356KxxMC/BD, S-8356LxxMC/BD, S-8356MxxMC/BD
Figure 22
Remark The power supply for the IC
chip is from the VDD pin.
SD
1 kΩ
VIN
VOUT
VSS
EXT
2200 pF
CIN
VDD
−
+
−
+
CL
L
−
+
PWM or PWM
/PFM switching
control circuit
Soft start
built-in reference
power supply
Phase
compensation
circuit
Oscillation circuit
IC
internal
power
supply
−
+
−
+
CL
ON/OFF
L
1 kΩ
VIN
VOUT
VSS
EXT
2200 pF
CIN
VDD
−
+
PWM or PWM
/PFM switching
control circuit
Soft start
built-in reference
power supply
Phase
compensation
circuit
Oscillation circuit
IC
internal
power
supply
Remark The power supply for
the IC chip is from the
VDD pin.
Figure 24
Figure 23
−
+
−
+
−
+
CL
ON/OFF
L
SD
1 kΩ
VIN
VSS
EXT
2200 pF
CIN
VDD
PWM or PWM
/PFM switching
control circuit
Soft start
built-in reference
power supply
Phase
compensation
circuit
Oscillation circuit
IC
internal
power
supply
Remark The power supply for the
IC chip is from the VDD
pin.
RA
CC
RB
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
30 Seiko Instruments Inc.
Power Dissipation of Package
Precautions
• Mount external capacitors, the diode, and the coil as close as possible to the IC.
• Characteristics ripple voltage and spike noise occur in IC containing switching regulators. Moreover rush
current flows at the time of a power supply injection. Because these largely depend on the coil, the
capacitor and impedance of power supply used, fully check them using an actually mounted model.
• Make sure that the dissipation of the switching transistor (especially at a high temperature) does not
exceed the allowable power dissipation of the package.
• The performance of this IC varies depending on the design of the PCB patterns, peripheral circuits and
external parts. Thoroughly test all settings with your device. Also, try to use the recommended external
parts. If not, contact an SII sales person.
• Do not apply an electrostatic discharge to this IC that exceeds the performance ratings of the built-in
electrostatic protection circuit.
• SII claims no responsibility for any disputes arising out of or in connection with any infringement by
products including this IC of patents owned by a third party.
Figure 25 Power Dissipation of Package (Before Mounting)
0 50 100 150
600
400
200
0
Power
Dissipation
PD
(mW)
Ambient Temperature Ta (°C)
SOT-23-3
SOT-89-3
6-Pin SNB(B)
SOT-23-5
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
31
Application Circuits
1. LCD Power Supply
The following example is an application power supply circuit (15 V/20 V output) to drive an LCD panel, and its
characteristics.
Figure 26 Power Supply Circuit for LCD
Table 26
Output
Voltage IC L Type Name TR Type
Name
SD Type
Name CL R
a R
b C
c Output
Characteristics
(1) 15 V S-8356M50 CDRH5D18-220 MCH3405 MA2Z748
F93 (20 V,10 µF) 580 kΩ 300 kΩ 15 pF (1-a),(1-b)
(2) 20 V S-8356M50 CDRH5D18-220 FDN337N MA729
F93 (25 V,10 µF) 575 kΩ 200 kΩ 15 pF (2-a),(2-b)
(3) 10 V S-8356Q50 CDRH5D18-100 MCH3405 MA2Z748
F93 (20 V,10 µF) 560 kΩ 560 kΩ 15 pF (3-a),(3-b)
SD
S-8356M50
S-8356Q50
EXT
VOUT
VSS
VDD
ON/OFF
VOUT
CL
CC
L
RB
RA
TR
CIN
VIN
−
+
+
−
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
32 Seiko Instruments Inc.
(1-a) Output current (IOUT) vs. Efficiency (η) (1-b) Output current (IOUT) vs. Output voltage (VOUT)
0
20
40
60
80
100
0.01 0.1 1 10 100
η [%]
IOUT [mA]
V
IN
=3.0 V
V
IN
=5.0 V
V
IN
=7.0 V
12
13
14
15
16
0.01 0.1 1 10 100
V
IN
=3.0 V
V
IN
=5.0 V
V
IN
=7.0 V
VOUT [V]
IOUT [mA]
(2-a) Output current (IOUT) vs. Efficiency (η) (2-b) Output current (IOUT) vs. Output voltage (VOUT)
0
20
40
60
80
100
0.01 0.1 1 10 100
η [%]
IOUT [mA]
V
IN
=3.0 V
V
IN
=5.0 V
V
IN
=7.0 V
14
16
18
20
22
0.01 0.1 1 10 100
IOUT [mA]
VOUT [V]
VIN=3.0 V
VIN=5.0 V
VIN=7.0 V
(3-a) Output current (IOUT) vs. Efficiency (η) (3-b) Output current (IOUT) vs. Output voltage (VOUT)
0
20
40
60
80
100
0.01 0.1 1 10 100
η [%]
IOUT [mA]
V
IN
=3.3 V
V
IN
=5.0 V
8
9
10
0.01 0.1 1 10 100
IOUT [mA]
VOUT [V]
7
VIN=3.3 V
VIN=5.0 V
11
Figure 27 LCD Power Supply Output Characteristics
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
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Seiko Instruments Inc.
33
2. Ceramic Capacitor (Application Example)
If using small ESR parts such as ceramic capacitors for the output capacitance, attach a resistor (R1)
corresponding to the ESR in series to the ceramic capacitor (CL) as shown in the following circuit.
R1 may depend on L, the capacitance, the wiring, and the application (output load).
The following example is a circuit using R1 = 100 mΩ, output voltage = 3.3 V, output load = 500 mA and its
characteristics.
Figure 28 Circuit Using Ceramic Capacitor
Table 27
IC L Type Name TR Type
Name
SD Type
Name
CL
(Ceramic Capacitor) R1 Output Characteristics
(1) S-8357F33 CDRH6D28-220 FDN335N M1FH3 10 µF × 2 100 mΩ (1-a), (1-b), (1-c)
(2) S-8358B50 CDRH6D28-470 FDN335N M1FH3 10 µF × 2 100 mΩ (2-a), (2-b), (2-c)
(3) S-8357N33 CDRH6D28-100 FDN335N M1FH3 10 µF × 2 100 mΩ (3-a), (3-b), (3-c)
EXT VOUT
VSS
VOUT
S
D
C
L
L
R1
TR
VIN C
IN
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S-8355/56/57/58 Series Rev.4.1_00
34 Seiko Instruments Inc.
(1-a) Output current (IOUT) vs. Efficiency (η) (1-b) Output current (IOUT) vs. Output voltage (VOUT)
0
20
40
60
80
100
0.01 0.1 1 10 100 1000
η [%]
IOUT [mA]
V
IN=0.9 V
V
IN=1.8 V
V
IN=2.7 V
3.28
3.29
3.30
3.31
3.32
0.01 0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
V
IN
=0.9 V
V
IN
=1.8 V
V
IN
=2.7 V
(1-c) Output current (IOUT) vs. Ripple voltage (Vr)
0
20
40
60
80
100
0.01 0.1 1 10 100 1000
Vr [mV]
IOUT [mA]
V
IN
=0.9 V
V
IN
=1.8 V
V
IN
=2.7 V
(2-a) Output current (IOUT) vs. Efficiency (η) (2-b) Output current (IOUT) vs. Output voltage (VOUT)
0
20
40
60
80
100
0.01 0.1 1 10 100 1000
η [%]
IOUT [mA]
V
IN
=2.0 V
V
IN
=3.0 V
V
IN
=4.0 V
5.03
5.04
5.05
5.06
5.07
0.01 0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
V
IN
=2.0 V
V
IN
=3.0 V
V
IN
=4.0 V
(2-c) Output current (IOUT) vs. Ripple voltage (Vr)
0
20
40
60
80
100
0.01 0.1 1 10 100 1000
Vr [mV]
IOUT [mA]
V
IN
=2.0 V
V
IN
=3.0 V
V
IN
=4.0 V
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
35
(3-a) Output current (IOUT) vs. Efficiency (η) (3-b) Output current (IOUT) vs. Output voltage (VOUT)
0
20
40
60
80
100
0.01 0.1 1 10 100 1000
η [%]
IOUT [mA]
V
IN
=0.9 V
V
IN
=1.8 V
V
IN
=2.7 V
3.28
3.29
3.30
3.31
3.32
0.01 0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
V
IN
=0.9 V
V
IN
=1.8 V
V
IN
=2.7 V
(3-c) Output current (IOUT) vs. Ripple voltage (Vr)
0
20
40
60
80
100
0.01 0.1 1 10 100 1000
Vr [mV]
IOUT [mA]
V
IN
=0.9 V
V
IN
=1.8 V
V
IN
=2.7 V
Figure 29 Ceramic Capacitor Circuit Output Characteristics
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
36 Seiko Instruments Inc.
Example of Major Temperature Characteristics (Ta =
==
= −
−−
−40 to 85°
°°
°C)
ISS1 vs. Ta (VOUT= 3.3 V, fosc= 100 kHz)
0
10
20
30
40
50
−40 −20 0 20 40 60 80 100
Ta [°C]
ISS1
[µA]
ISS1 vs. Ta (VOUT= 3.3 V, fosc= 300 kHz)
0
10
20
30
40
50
−40 −20 0 20 40 60 80 100
Ta [°C]
ISS1
[µA]
ISS1 vs. Ta (VOUT= 3.3 V, fosc= 600 kHz)
0
20
40
60
80
100
−40 −20 0 20 40 60 80 100
Ta [°C]
ISS1
[µA]
ISS2 vs. Ta (VOUT= 3.3 V, fosc= 100 kHz)
0
2
4
6
8
10
−40 −20 0 20 40 60 80 100
Ta [°C]
ISS2
[µA]
ISS2 vs. Ta (VOUT= 3.3 V, fosc= 300 kHz)
0
2
4
6
8
10
−40 −20 0 20 40 60 80 100
Ta [°C]
ISS2
[µA]
ISS2 vs. Ta (VOUT= 3.3 V, fosc= 600 kHz)
0
2
4
6
8
10
−40 −20 0 20 40 60 80 100
Ta [°C]
ISS2
[µA]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
37
ISSS vs. Ta (VOUT= 3.3 V, fosc= 100 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
−40 −20 0 20 40 60 80 100
Ta [°C]
ISSS
[µA]
ISSS vs. Ta (VOUT= 3.3 V, fosc= 300 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
−40 −20 0 20 40 60 80 100
Ta [°C]
ISSS
[µA]
IEXTH vs. Ta (VOUT= 3.3 V,fosc= 300 kHz)
-
−10
−20
−30
−40
−50
−60
−40 −20 0 20 40 60 80 100
Ta [°C]
IEXTH
[mA]
0
I EXTL vs. Ta (VOUT= 3.3 V,fosc= 300 kHz)
0
10
20
30
40
50
60
−40 −20 0 20 40 60 80 100
Ta [°C]
IEXTL
[mA]
fosc vs. Ta (VOUT= 3.3 V, fosc= 100 kHz)
50
75
100
125
150
−40 −20 0 20 40 60 80 100
Ta [°C]
f
osc
[kHz]
f osc vs. Ta (VOUT= 3.3 V, fosc= 300 kHz)
200
250
300
350
400
−40 −20 0 20 40 60 80 100
Ta [°C]
f
osc
[kHz]
f osc vs. Ta (VOUT= 3.3 V, fosc= 600 kHz)
400
500
600
700
800
−40 −20 0 20 40 60 80 100
Ta [°C]
f
osc
[kHz]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
38 Seiko Instruments Inc.
MaxDuty vs. Ta (VOUT= 3.3 V, fosc= 100 kHz)
70
75
80
85
90
−40 −20 0 20 40 60 80 100
Ta [°C]
MaxDuty
[%]
MaxDuty vs. Ta (VOUT= 3.3 V, fosc= 300 kHz)
70
75
80
85
90
−40 −20 0 20 40 60 80 100
Ta [°C]
MaxDuty
[%]
MaxDuty vs. Ta (VOUT= 3.3 V, fosc= 600 kHz)
70
75
80
85
90
−40 −20 0 20 40 60 80 100
Ta [°C]
MaxDuty
[%]
PFMDuty vs. Ta (VOUT= 3.3 V, fosc= 100 kHz)
S-8356/58 Series
5
10
15
20
25
−40 −20 0 20 40 60 80 100
Ta [°C]
PFMDuty
[%]
VSH vs. Ta (VOUT= 3.3 V, fosc= 300 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
−40 −20 0 20 40 60 80 100
Ta [°C]
V
SH
[V]
VSL1 vs. Ta (VOUT= 3.3 V, fosc= 300 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
−40 −20 0 20 40 60 80 100
Ta [°C]
V
SL1
[V]
VSL2 vs. Ta (VOUT= 1.4 V, fosc= 300 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
−40 −20 0 20 40 60 80 100
Ta [°C]
V
SL2
[V]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
39
tSS vs. Ta (VOUT= 3.3 V, fOSC= 100 kHz)
0
2
4
6
8
−40 −20 0 20 40 60 80 100
Ta [°C]
tSS
[ms]
tSS vs. Ta (VOUT= 3.3 V, fOSC= 300 kHz)
0
2
4
6
8
−40 −20 0 20 40 60 80 100
Ta [°C]
tSS
[ms]
tSS vs. Ta (VOUT= 3.3 V, fOSC= 600 kHz)
0
2
4
6
8
−40 −20 0 20 40 60 80 100
Ta [°C]
tSS
[ms]
VST1 vs. Ta (VOUT= 3.3 V, fOSC= 100 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
−40 −20 0 20 40 60 80 100
Ta [°C]
VST1
[V]
VST2 vs. Ta (VOUT= 3.3 V, fOSC= 100 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
−40 −20 0 20 40 60 80 100
Ta [°C]
VST2
[V]
VOUT vs. Ta (VOUT= 3.3 V, fOSC= 100 kHz)
3.20
3.25
3.30
3.35
3.40
−40 −20 0 20 40 60 80 100
Ta [°C]
VOUT
[V]
VOUT vs. Ta (VOUT= 3.3 V, fOSC= 300 kHz)
3.20
3.25
3.30
3.35
3.40
−40 −20 0 20 40 60 80 100
Ta [°C]
VOUT
[V]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
40 Seiko Instruments Inc.
VOUT vs. Ta (VOUT= 3.3 V, fOSC= 600 kHz)
3.20
3.25
3.30
3.35
3.40
−40 −20 0 20 40 60 80 100
Ta [°C]
VOUT
[V]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
41
Example of Major Power Supply Dependence Characteristics (Ta =
==
= 25°
°°
°C)
ISS1,2 vs. VDD (VOUT = 3.3 V, fOSC= 300 kHz)
0
10
20
30
40
50
0 2 4 6 8 10
VDD [V]
ISS1,2
[µA]
ISS1,2 vs. VDD (VOUT = 3.3 V, fOSC= 600 kHz)
0
20
40
60
80
100
0 2 4 6 8 10
VDD [V]
ISS1,2
[µA]
ISSS vs. VDD (VOUT = 3.3 V, fOSC= 300 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
0 2 4 6 8 10
VDD [V]
ISSS
[µA]
fOSC vs. VDD (fOSC= 100 kHz)
20
40
60
80
100
120
0 2 4 6 8 10
VDD
[
V
]
fosc
[kHz]
f OSC vs. VDD (fOSC= 300 kHz)
60
120
180
240
300
360
0 2 4 6 8 10
VDD
[
V
]
fosc
[kHz]
f OSC vs. VDD (fOSC= 600 kHz)
120
240
360
480
600
720
0 2 4 6 8 10
VDD
[
V
]
fosc
[kHz]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
42 Seiko Instruments Inc.
MaxDuty vs. VDD (fOSC= 100 kHz)
50
60
70
80
90
100
0 2 4 6 8 10
VDD
[
V
]
MaxDuty
[%]
MaxDuty vs. VDD (fOSC= 300 kHz)
50
60
70
80
90
100
0 2 4 6 8 10
VDD
[
V
]
MaxDuty
[%]
MaxDuty vs. VDD (fOSC= 600 kHz)
50
60
70
80
90
100
0 2 4 6 8 10
VDD
[
V
]
MaxDuty
[%]
IEXTH vs. VDD
-
−20
−40
−60
−80
−100
0 2 4 6 8 10
VDD
[
V
]
IEXTH
[mA]
0
IEXTL vs. VDD
-
−20
−40
−60
−80
−100
0 2 4 6 8 10
VDD
[
V
]
IEXTL
[mA]
0
VDD
[
V
]
VOUT
[V]
1.5
2.0
2.5
3.0
3.5
0 2 4 6 8 10
VOUT vs. VDD
(VOUT= 3.3 V, fOSC= 100 kHz, VDD separate type)
VIN= 1.98 V, IOUT= 66 mA
VDD [V]
VOUT
[V]
1.5
2.0
2.5
3.0
3.5
0 2 4 6 8 10
VOUT vs. VDD
(VOUT= 3.3 V, fOSC= 300 kHz, VDD separate type)
VIN= 1.98 V, IOUT= 66 mA
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
43
VDD
[
V
]
VOUT
[V]
1.5
2.0
2.5
3.0
3.5
0 2 4 6 8 10
VOUT vs. VDD
(VOUT= 3.3 V, fOSC= 600 kHz, VDD separate type)
VIN= 1.98 V, IOUT= 66 mA
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
44 Seiko Instruments Inc.
Output Waveforms
1. S-8358B33MC
1-1. IOUT = 1 mA 1-2. IOUT = 20 mA
−25
−20
−15
−10 −5 0 5 10 15 20 25
Time [µs]
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/di v]
−25
−20
−15
−10 −5 0 5 10 15 20 25
Time [µs]
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/di v]
CONT
voltage
[2.0 V/di v]
1-3. IOUT = 100 mA 1-4. IOUT = 200 mA
−25
−20
−15
−10 −5 0 5 10 15 20 25
Time [µs]
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/div]
−25
−20
−15
−10 −5 0 5 10 15 20 25
Time [µs]
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/div]
2. S-8358F33MC
2-1. IOUT = 1 mA 2-2. IOUT = 10 mA
−10 −8 −6 −4 −2 0 2 4 6 8 10
Time [µs]
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/div]
−10 −8 −6 −4 −2 0 2 4 6 8 10
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/div]
Time [µs]
2-3. IOUT = 100 mA 2-4. IOUT = 200 mA
−10 −8 −6 −4 −2 0 2 4 6 8 10
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/div]
Time [µs]
−10 −8 −6 −4 −2 0 2 4 6 8 10
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/div]
Time [µs]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
45
3. S-8358N33MC
3-1. IOUT = 1 mA 3-2. IOUT = 10 mA
−5 −4 −3 −2 −1 0 1 2 3 4 5
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/div]
Time [µs]
−5 −4 −3 −2 −1 0 1 2 3 4 5
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/div]
Time [µs]
3-3. IOUT = 100 mA 3-4. IOUT = 200 mA
−5 −4 −3 −2 −1 0 1 2 3 4 5
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/div]
Time [µs]
−5 −4 −3 −2 −1 0 1 2 3 4 5
4
2
0
3.40
3.35
3.30
3.25
Output
voltage
[0.05 V/div]
CONT
voltage
[2.0 V/div]
3.20
Time [µs]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
46 Seiko Instruments Inc.
Examples of Transient Response characteristics
1. Powering ON (VIN: 0 V → 2.0 V)
1-1. 100 kHz, IOUT = 1 mA 1-2. 100 kHz, IOUT = 100 mA
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
V
IN
[V]
0
2
4 VOUT
[V]
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VIN
[V]
0
2
4 VOUT
[V]
1-3. 300 kHz, IOUT = 1 mA 1-4. 300 kHz, IOUT = 100 mA
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VIN
[V]
0
2
4 VOUT
[V]
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VIN
[V]
0
2
4 VOUT
[V]
1-5. 600 kHz, IOUT = 1 mA 1-6. 600 kHz, IOUT = 100 mA
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VIN
[V]
0
2
4 VOUT
[V]
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VIN
[V]
0
2
4 VOUT
[V]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
47
2. Responses of shutdown pin (VON/OFF: 0 V → 2.0 V)
2-1. 100 kHz, IOUT = 1 mA 2-2. 100 kHz, IOUT = 100 mA
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VON/OFF
[V]
0
2
4 VOUT
[V]
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VON/OFF
[V]
0
2
4 VOUT
[V]
2-3. 300 kHz, IOUT = 1 mA 2-4. 300 kHz, IOUT = 100 mA
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VON/OFF
[V]
0
2
4 VOUT
[V]
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VON/OFF
[V]
0
2
4 VOUT
[V]
2-5. 600 kHz, IOUT = 1 mA 2-6. 600 kHz, IOUT = 100 mA
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VON/OFF
[V]
0
2
4 VOUT
[V]
0
2
−1 0 1 2 3 4 5 6 7 8 9
time
[
ms
]
VON/OFF
[V]
0
2
4 VOUT
[V]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
48 Seiko Instruments Inc.
3. Load fluctuations
3-1. 100 kHz, IOUT: 100 µA → 100 mA 3-2. 100 kHz, IOUT: 100 mA → 100 µA
−0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
time
[
ms
]
3.00
3.20
3.40
3.60
VOUT
[0.2 V/div]
100 µA
IOUT
100 mA
−10 0 10 20 30 40 50 60 70 80 90
time
[
ms
]
3.20
3.40
3.60
3.80
VOUT
[0.2 V/div]
100 µA
IOUT
100 mA
3-3. 300 kHz, IOUT: 100 µA → 100 mA 3-4. 300 kHz, IOUT: 100 mA → 100 µA
−0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
time
[
ms
]
3.00
3.20
3.40
3.60
VOUT
[0.2 V/div]
100 µA
IOUT
100 mA
−10 0 10 20 30 40 50 60 70 80 90
time
[
ms
]
3.20
3.40
3.60
3.80
VOUT
[0.2 V/div]
100 µA
IOUT
100 mA
3-5. 600 kHz, IOUT: 0.1 mA → 100 mA 3-6. 600 kHz, IOUT: 100 mA → 0.1 mA
time
[
ms
]
3.00
3.20
3.40
3.60
VOUT
[0.2 V/div]
100 µA
IOUT
100 mA
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
−
0.2
−0.5 0 0.5 1.0 1.5 2.0 2.5 3.0
time
[
ms
]
3.00
3.20
3.40
3.60
VOUT
[0.2 V/div]
100 µA
IOUT
100 mA 3.80
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
49
4. Input voltage fluctuations
4-1. 100 kHz, IOUT = 100 mA, VIN = 1.98 V → 2.64 V 4-2. 100 kHz, IOUT = 100 mA, VIN = 2.64 V → 1.98 V
1.5
2.0
2.5
3.0
−0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
time
[
ms
]
3.25
3.30
3.35
3.40
3.45
VIN
[V]
VOUT
[V]
1.5
2.0
2.5
3.0
−0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
time
[
ms
]
3.25
3.30
3.35
3.40
3.45
VIN
[V]
VOUT
[V]
4-3. 300 kHz, IOUT = 100 mA, VIN = 1.98 V → 2.64 V 4-4. 100 kHz, IOUT = 100 mA, VIN=2.64 V → 1.98 V
1.5
2.0
2.5
3.0
−0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
time
[
ms
]
3.25
3.30
3.35
3.40
3.45
VIN
[V]
VOUT
[V]
1.5
2.0
2.5
3.0
−0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
time
[
ms
]
3.25
3.30
3.35
3.40
3.45
VIN
[V]
VOUT
[V]
4-5. 600 kHz, IOUT = 100 mA, VIN = 1.98 V → 2.64 V 4-6. 600 kHz, IOUT = 100 mA, VIN = 2.64 V → 1.98 V
1.5
2.0
2.5
3.0
−0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
time
[
ms
]
3.25
3.30
3.35
3.40
3.45
VIN
[V]
VOUT
[V]
1.5
2.0
2.5
3.0
−0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
time
[
ms
]
3.25
3.30
3.35
3.40
3.45
VIN
[V]
VOUT
[V]
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
50 Seiko Instruments Inc.
Reference Data
Use this reference data to choose the external parts. This reference data makes it possible to choose the
recommended external part based on the application and characteristics data.
1. Reference data for external parts
Table 28 Efficiency vs. Output Characteristics and Output Voltage vs.
Output Current Characteristics for External Parts
No. Product
Name
Oscillation
Frequency
Output
Voltage
Control
System Inductor Transistor Diode Output Capacitor
1 S-8357F33 300 kHz 3.3 V PWM CDRH104R-220
S-90N0312SMA
M1FH3 F93 (16 V, 47 µF) × 2
2 S-8357F50 300 kHz 5.0 V PWM
3 S-8356M50 300 kHz 5.0 V PWM/PFM
4 S-8357B33 100 kHz 3.3 V PWM CDRH104R-470
5 S-8358B33 100 kHz 3.3 V PWM/PFM
S-90N0442SUA
6 S-8357B50 100 kHz 5.0 V PWM
7 S-8356M50 300 kHz 5.0 V PWM/PFM CDRH8D28-220
S-90N0212SMA
F93 (16 V, 47 µF)
8 S-8357B33 100 kHz 3.3 V PWM CDRH8D28-470
9 S-8358B33 100 kHz 3.3 V PWM/PFM
10 S-8357B50 100 kHz 5.0 V PWM
11 S-8357F33 300 kHz 3.3 V PWM CXLP120-220 MA2Z748 F92 (6.3 V, 47 µF)
12 S-8356M50 300 kHz 5.0 V PWM/PFM
13 S-8357N33 600 kHz 3.3 V PWM CDRH8D28-100
M1FH3 F93 (16 V, 47 µF)
14 S-8357N50 600 kHz 5.0 V PWM
15 S-8356Q33 600 kHz 3.3 V PWM/PFM
16 S-8356Q50 600 kHz 5.0 V PWM/PFM
The properties of the external parts are shown below.
Table 29 Properties of External Parts
Part Product Name Manufacturer Characteristics
Inductor CDRH104R-220 Sumida Corporation
22 µH, DCR*1 = 73 mΩ, IMAX*2 = 2.5 A, Height = 4.0 mm
CDRH104R-470 47 µH, DCR*1 = 128 mΩ, IMAX*2 = 1.9 A, Height = 4.0 mm
CDRH8D28-100 10 µH, DCR*1 = 47 mΩ, IMAX*2 = 2.7 A, Height = 3.0 mm
CDRH8D28-220 22 µH, DCR*1 = 99 mΩ, IMAX*2 = 1.8 A, Height = 3.0 mm
CDRH8D28-470 47 µH, DCR*1 = 195 mΩ, IMAX*2 = 1.25 A, Height = 3.0 mm
CXLP120-220 Sumitomo Special
Metals Co., Ltd. 22 µH, DCR*1 = 590 mΩ, IMAX*2 = 0.55 A, Height = 1.2 mm
Diode M1FH3
Shindengen Electric
Manufacturing Co., Ltd. VF*3 = 0.3 V, IF*4 = 1.5 A
MA2Z748
Matsushita Electric
Industrial Co., Ltd. VF*3 = 0.4 V, IF*4 = 0.3 A
F93 Nichicon Corporation 16 V, 47 µF Capacitor
(Output capacitance) F92 6.3 V, 47 µF
Transistor
(Nch FET) S-90N0212SMA Seiko Instruments Inc. VDSS *5 = 20 V max., VGSS*6 = 12 V max., CISS*7 = 190 pF,
RDS(ON)*8 = 0.16 Ω max. (VGS*9 = 2.5 V, ID*10 = 0.5 A)
S-90N0312SMA
VDSS *5 = 20 V max., VGSS*6 = 8 V max., CISS*7 = 170 pF,
RDS(ON)*8 = 0.14 Ω max. (VGS*9 = 2.5 V, ID*10 = 0.5 A)
S-90N0442SUA VDSS *5 = 20 V max., VGSS*6 = 8 V max., CISS*7 = 390 pF,
RDS(ON)*8 = 0.07 Ω max. (VGS*9 = 2.5 V, ID*10 = 2.0 A)
*1. DC resistance, *2. Maximum allowable current, *3. Forward voltage, *4. Forward current, *5. Drain-source voltage,
*6. Gate-source voltage, *7. Input capacitance, *8. Drain-source on resistance, *9 Gate-source voltage, *10 Drain current
Caution The values shown in the characteristics column of Table 29 above are based on the materials
provided by each manufacturer. However, consider the characteristics of the original materials when
using the above products.
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
51
2. Reference data (1)
The data of (a) output current (IOUT) vs. efficiency (η) characteristics and (b) output current (IOUT) vs. output
voltage (VOUT) characteristics under conditions of (1) to (16) shown in Table 28 is shown below.
(1) S-8357F33
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT
[
mA
]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
(2) S-8357F50
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
(3) S-8356M50
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000
0.1
η [%]
IOUT [mA]
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
52 Seiko Instruments Inc.
(4) S-8357B33
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
(5) S-8358B33
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
(6) S-8357B50
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
V
IN
=2.0 V
VIN=3.0 V
VIN=4.0 V
(7) S-8356M50
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=3.0 V
VIN=4.0 V
V
IN
=2.0 V
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
53
(8) S-8357B33
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=0.9 V
V
IN
=1.8 V
VIN=2.7 V
(9) S-8358B33
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
(10) S-8357B50
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000
0.1
η [%]
IOUT [mA]
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=2.0 V
V
IN
=3.0 V
VIN=4.0 V
(11) S-8357F33
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=0.9 V
V
IN
=1.8 V
VIN=2.7 V
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
54 Seiko Instruments Inc.
(12) S-8356M50
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VOUT [V]
IOUT [mA]
VIN=2.0 V
V
IN
=3.0 V
VIN=4.0 V
(13) S-8357N33
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
0
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
VOUT [V]
1 10 100 1000 0.1
IOUT [mA]
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
(14) S-8357N50
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
0
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
4.7
4.8
4.9
5.0
5.1
5.2
VOUT [V]
1 10 100 1000 0.1
IOUT [mA]
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
(15) S-8356Q33
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
0
VIN=1.8 V
VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
VOUT [V]
1 10 100 1000 0.1
IOUT [mA]
V
IN
=1.8 V
VIN=2.7 V
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
55
(16) S-8356Q50
(a) Output current (IOUT) vs. Efficiency (η) (b) Output current (IOUT) vs. Output voltage (VOUT)
20
40
60
80
100
1 10 100 1000 0.1
η [%]
IOUT [mA]
0
VIN=3.0 V
VIN=4.0 V
4.7
4.8
4.9
5.0
5.1
5.2
VOUT [V]
1 10 100 1000 0.1
IOUT [mA]
VIN=3.0 V
V
IN
=4.0 V
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
S-8355/56/57/58 Series Rev.4.1_00
56 Seiko Instruments Inc.
3. Reference data (2)
The actual output current vs. ripple voltage characteristics data under conditions of (1) to (16) in Table 28
are shown below.
(1) S-8357F33 (2) S-8357F50
0
50
100
150
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
V
IN
=0.9 V
V
IN
=1.8 V
V
IN
=2.7 V
0
50
100
150
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
(3) S-8356M50 (4) S-8357B33
0
50
100
150
Vr [mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
0
50
100
150
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
(5) S-8358B33 (6) S-8357B50
0
50
100
150
Vr [mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=0.9 V
V
IN
=1.8 V
VIN=2.7 V
0
50
100
150
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
(7) S-8356M50 (8) S-8357B33
0
50
100
150
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=2.0 V
V
IN
=3.0 V
VIN=4.0 V
0
50
100
150
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
SUPER-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATOR
Rev.4.1_00 S-8355/56/57/58 Series
Seiko Instruments Inc.
57
(9) S-8358B33 (10) S-8357B50
0
50
100
150
Vr [mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=0.9 V
V
IN
=1.8 V
VIN=2.7 V
0
50
100
150
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
(11) S-8357F33 (12) S-8356M50
0
50
100
150
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
0
50
100
150
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
(13) S-8357N33 (14) S-8357N50
Vr [mV]
IOUT [mA]
0.1 1 10 100 1000
20
40
60
80
100
0
VIN=0.9 V
VIN=1.8 V
VIN=2.7 V
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
20
40
60
80
100
0
VIN=2.0 V
VIN=3.0 V
VIN=4.0 V
(15) S-8356Q33 (16) S-8356Q50
Vr [mV]
IOUT [mA]
0.1 1 10 100 1000
20
40
60
80
100
0
VIN=1.8 V
VIN=2.7 V
Vr [ mV]
IOUT [mA]
0.1 1 10 100 1000
20
40
60
80
100
0
VIN=3.0 V
VIN=4.0 V
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
0.4±0.05
1.5±0.1
4.5±0.1
1.6±0.2
1.5±0.1 1.5±0.1
0.45±0.1
0.4±0.1
0.4±0.1
45°
312
No. UP003-A-P-SD-1.1
UP003-A-P-SD-1.1
SOT893-A-PKG Dimensions
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
2.0±0.1
0.3±0.05
8.0±0.1
ø1.5+0.1
-0
2.0±0.05
ø1.5+0.1
-0
4.75±0.1
5° max.
No. UP003-A-C-SD-1.1
UP003-A-C-SD-1.1
SOT893-A-Carrier Tape
Feed direction
4.0±0.1(10 pitches : 40.0±0.2)
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
13.0±0.3
16.5max.
(60°)
(60°)
QTY. 1,000
No. UP003-A-R-SD-1.1
UP003-A-R-SD-1.1
SOT893-A-Reel
Enlarged drawing in the central part
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
2.9±0.2
0.95±0.1
1.9±0.2
+0.1
-0.05
0.16
0.4±0.1
1
23
No. MP003-A-P-SD-1.1
MP003-A-P-SD-1.1
SOT233-A-PKG Dimensions
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
1.6±0.1
0.25±0.05
4.0±0.1
2.0±0.1
4.0±0.1
1.5 +0.1
-0.05
1.1±0.1
2.85±0.2
No. MP003-A-C-SD-1.1
MP003-A-C-SD-1.1
SOT233-A-Carrier Tape
Feed direction
1
23
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
(60°)
(60°)
ø13±0.2
12.5max.
9.0±0.3
QTY. 3,000
No. MP003-A-R-SD-1.1
MP003-A-R-SD-1.1
SOT233-A-Reel
Enlarged drawing in the central part
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
2.9±0.2
1.9±0.2
0.95±0.1
0.4±0.1
0.16 +0.1
-0.06
123
4
5
No. MP005-A-P-SD-1.2
MP005-A-P-SD-1.2
SOT235-A-PKG Dimensions
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
ø1.5 +0.1
-0 2.0±0.05
ø1.0 +0.2
-0 4.0±0.1
1.4±0.2
0.25±0.1
3.2±0.2
123
45
No. MP005-A-C-SD-2.1
MP005-A-C-SD-2.1
SOT235-A-Carrier Tape
Feed direction
4.0±0.1(10 pitches:40.0±0.2)
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
12.5max.
9.0±0.3
ø13±0.2
(60°) (60°)
QTY. 3,000
No. MP005-A-R-SD-1.1
MP005-A-R-SD-1.1
SOT235-A-Reel
Enlarged drawing in the central part
1.8±0.15
0.5±0.1 0.5±0.1
0.8±0.05
0.14±0.05
R(0.075)
0.2±0.08
(0.125)
123
456
SNB6B-A-PKG Dimensions
No. BD006-A-P-SD-1.1
Seiko Instruments Inc.
No.
TITLE
SCALE
UNIT mm
BD006-A-P-SD-1.1
No.
TITLE
SCALE
UNIT mm
4.0±0.1
2.0±0.05
4.0±0.1
ø1.5±0.1
2.2±0.1
1.1±0.1
0.25±0.05
ø1.1±0.1
Seiko Instruments Inc.
Feed direction
SNB6B-A-Carrier Tape
No. BD006-A-C-SD-2.1
BD006-A-C-SD-2.1
1
2
3
6
5
4
QTY. 3,000
No.
TITLE
SCALE
UNIT mm
12.5max.
9.0±0.3
ø13±0.2
Seiko Instruments Inc.
Enlarged drawing in the central part
SNB6B-A-Reel
No. BD006-A-R-SD-1.1
BD006-A-R-SD-1.1
• The information described herein is subject to change without notice.
• Seiko Instruments Inc. is not responsible for any problems caused by circuits or diagrams described herein
whose related industrial properties, patents, or other rights belong to third parties. The application circuit
examples explain typical applications of the products, and do not guarantee the success of any specific
mass-production design.
• When the products described herein are regulated products subject to the Wassenaar Arrangement or other
agreements, they may not be exported without authorization from the appropriate governmental authority.
• Use of the information described herein for other purposes and/or reproduction or copying without the
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failure or malfunction of semiconductor products may occur. The user of these products should therefore
give thorough consideration to safety design, including redundancy, fire-prevention measures, and
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