S-1112/1122 Series
www.sii-ic.com
HIGH RIPPLE-REJECTION AND LOW DROPOUT
CMOS VOLTAGE REGULATOR
© Seiko Instruments Inc., 2002-2010 Rev.6.0_00
Seiko Instruments Inc. 1
The S-1112/1122 Series is a positive voltage regulator with a low dropout voltage, high output voltage
accuracy, and low current consumption developed based on CMOS technology.
A built-in low on-resistance transistor provides a low dropout voltage and large output current, and a built-in
overcurrent protector prevents the load current from exceeding the current capacitance of the output transistor.
An ON/OFF circuit ensures a long battery life. Compared with the voltage regulators using the conventional
CMOS process, a larger variety of capacitors are available, including small ceramic capacitors. Small SNT-
6A(H) (S-1112 Series only) and SOT-23-5 packages realize high-density mounting. In SOT-23-5, the lineup
includes the S-1112 and S-1122 Series, which differ in pin configuration.
Features
• Output voltage: 1.5 V to 5.5 V, selectable in 0.1 V steps.
• High-accuracy output voltage: ±1.0%
• Low dropout voltage: 190 mV typ. (3.0 V output product, IOUT = 100 mA)
• Low current consumption: During operation: 50 μA typ., 90 μA max.
During shutdown: 0.1 μA typ., 1.0 μA max.
• High peak current capability: 150 mA output is possible (at VIN ≥ VOUT(S) + 1.0 V)*1
• Built-in ON/OFF circuit: Ensures long battery life.
• Low ESR capacitor can be used: A ceramic capacitor of 0.47 μF or more can be used for the output
capacitor.
• High ripple rejection: 80 dB typ. (at 1.0 kHz)
• Built-in overcurrent protector: Overcurrent of output transistor can be restricted.
• Lead-free, Sn 100%, halogen-free*2
*1. Attention should be paid to the power dissipation of the package when the output current is large.
*2. Refer to “ Product Name Structure” for details.
Applications
• Power supply for battery-powered devices
• Power supply for personal communication devices
• Power supply for home electric/electronic appliances
• Power supply for cellular phones
Packages
• SNT-6A(H)
• SOT-23-5
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
2
Block Diagram
Reference
voltage circuit
ON/OFF
*1. Parasitic diode
*1
ON/OFF
circuit
+
−
VIN
VSS
VOUT
O vercurrent
protector
Figure 1
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.6.0_00 S-1112/1122 Series
Seiko Instruments Inc. 3
Product Name Structure
The product types and output voltage for the S-1112/1122 Series can be selected at the user’s request.
Refer to the “1. Product Name” for the construction of the product name, “2. Package” regarding the
package drawings and “3. Product Name List” for the full product names.
1. Product name
(1) S-1112 Series
S-1112 x xx xx
−
xxx TF x
Output voltage
15 to 55
(E.g., when the output voltage is 1.5 V,
it is ex
p
ressed as 15.
)
IC direction in ta
p
e s
p
ecifications*1
Package name (a bbreviation)
PI : SNT-6A(H)
MC: SOT-23-5
Environm ental code
U:
Lead-free (Sn 100%), halogen-f ree
G: Lead-free (for details, please contact our sales offi ce)
Product name (abbreviation)*2
Product type*3
A: ON/OFF pin negative logic
B: ON/OFF pi n positive logic
*1. Refer to the tape specifications at the end of this book.
*2. Refer to the product name list.
*3. Refer to 3. Shutdown pin (ON/OFF pin) in the “ Operation”.
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
4
(2) S-1122 Series
S-1122 x xx MC − xxx TF x
Output voltage
15 to 55
(E.g., when the output volt a ge is 1.5 V,
it is ex
p
ressed as 15.
)
Package name (abbreviation)
MC: SOT-23-5
Environmental code
U:
Lead-free (Sn 100%), halogen-free
G: Lead-free (for details, please contact ou r sales office)
Product type*3
A: ON/OFF pin negative logic
B: ON/OFF pin positi ve logic
IC direction in ta
p
e s
p
ecifications*1
Product name (abbreviation)*2
*1. Refer to the tape specifications at the end of this book.
*2. Refer to the product name list.
*3. Refer to 3. Shutdown pin (ON/OFF pin) in the “ Operation”.
2. Package
Drawing code
Package name Package Tape Reel Land
SNT-6A(H) PI006-A-P-SD PI006-A-C-SD PI006-A-R-SD PI006-A-L-SD
SOT-23-5 MP005-A-P-SD MP005-A-C-SD MP005-A-R-SD ⎯
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.6.0_00 S-1112/1122 Series
Seiko Instruments Inc. 5
3. Product name list
(1) S-1112 Series
Table 1
Output Voltage SNT-6A(H) SOT-23-5
1.5 V ±1.0% S-1112B15PI-L6ATFx S-1112B15MC-L6ATFx
1.6 V ±1.0% S-1112B16PI-L6BTFx S-1112B16MC-L6BTFx
1.7 V ±1.0% S-1112B17PI-L6CTFx S-1112B17MC-L6CTFx
1.8 V ±1.0% S-1112B18PI-L6DTFx S-1112B18MC-L6DTFx
1.9 V ±1.0% S-1112B19PI-L6ETFx S-1112B19MC-L6ETFx
2.0 V ±1.0% S-1112B20PI-L6FTFx S-1112B20MC-L6FTFx
2.1 V ±1.0% S-1112B21PI-L6GTFx S-1112B21MC-L6GTFx
2.2 V ±1.0% S-1112B22PI-L6HTFx S-1112B22MC-L6HTFx
2.3 V ±1.0% S-1112B23PI-L6ITFx S-1112B23MC-L6ITFx
2.4 V ±1.0% S-1112B24PI-L6JTFx S-1112B24MC-L6JTFx
2.5 V ±1.0% S-1112B25PI-L6KTFx S-1112B25MC-L6KTFx
2.6 V ±1.0% S-1112B26PI-L6LTFx S-1112B26MC-L6LTFx
2.7 V ±1.0% S-1112B27PI-L6MTFx S-1112B27MC-L6MTFx
2.8 V ±1.0% S-1112B28PI-L6NTFx S-1112B28MC-L6NTFx
2.85 V ±1.0% S-1112B2JPI-L7PTFx S-1112B2JMC-L7PTFx
2.9 V ±1.0% S-1112B29PI-L6OTFx S-1112B29MC-L6OTFx
3.0 V ±1.0% S-1112B30PI-L6PTFx S-1112B30MC-L6PTFx
3.1 V ±1.0% S-1112B31PI-L6QTFx S-1112B31MC-L6QTFx
3.2 V ±1.0% S-1112B32PI-L6RTFx S-1112B32MC-L6RTFx
3.3 V ±1.0% S-1112B33PI-L6STFx S-1112B33MC-L6STFx
3.4 V ±1.0% S-1112B34PI-L6TTFx S-1112B34MC-L6TTFx
3.5 V ±1.0% S-1112B35PI-L6UTFx S-1112B35MC-L6UTFx
3.6 V ±1.0% S-1112B36PI-L6VTFx S-1112B36MC-L6VTFx
3.7 V ±1.0% S-1112B37PI-L6WTFx S-1112B37MC-L6WTFx
3.8 V ±1.0% S-1112B38PI-L6XTFx S-1112B38MC-L6XTFx
3.9 V ±1.0% S-1112B39PI-L6YTFx S-1112B39MC-L6YTFx
4.0 V ±1.0% S-1112B40PI-L6ZTFx S-1112B40MC-L6ZTFx
4.1 V ±1.0% S-1112B41PI-L7ATFx S-1112B41MC-L7ATFx
4.2 V ±1.0% S-1112B42PI-L7BTFx S-1112B42MC-L7BTFx
4.3 V ±1.0% S-1112B43PI-L7CTFx S-1112B43MC-L7CTFx
4.4 V ±1.0% S-1112B44PI-L7DTFx S-1112B44MC-L7DTFx
4.5 V ±1.0% S-1112B45PI-L7ETFx S-1112B45MC-L7ETFx
4.6 V ±1.0% S-1112B46PI-L7FTFx S-1112B46MC-L7FTFx
4.7 V ±1.0% S-1112B47PI-L7GTFx S-1112B47MC-L7GTFx
4.8 V ±1.0% S-1112B48PI-L7HTFx S-1112B48MC-L7HTFx
4.9 V ±1.0% S-1112B49PI-L7ITFx S-1112B49MC-L7ITFx
5.0 V ±1.0% S-1112B50PI-L7JTFx S-1112B50MC-L7JTFx
5.1 V ±1.0% S-1112B51PI-L7KTFx S-1112B51MC-L7KTFx
5.2 V ±1.0% S-1112B52PI-L7LTFx S-1112B52MC-L7LTFx
5.3 V ±1.0% S-1112B53PI-L7MTFx S-1112B53MC-L7MTFx
5.4 V ±1.0% S-1112B54PI-L7NTFx S-1112B54MC-L7NTFx
5.5 V ±1.0% S-1112B55PI-L7OTFx S-1112B55MC-L7OTFx
Remark 1. Please contact our sales office for type A products.
2. x: G or U
3. Please select products of environmental code = U for Sn 100%, halogen-free products.
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
6
(2) S-1122 Series
Table 2
Output Voltage SOT-23-5
1.5 V ±1.0% S-1122B15MC-L8ATFx
1.6 V ±1.0% S-1122B16MC-L8BTFx
1.7 V ±1.0% S-1122B17MC-L8CTFx
1.8 V ±1.0% S-1122B18MC-L8DTFx
1.9 V ±1.0% S-1122B19MC-L8ETFx
2.0 V ±1.0% S-1122B20MC-L8FTFx
2.1 V ±1.0% S-1122B21MC-L8GTFx
2.2 V ±1.0% S-1122B22MC-L8HTFx
2.3 V ±1.0% S-1122B23MC-L8ITFx
2.4 V ±1.0% S-1122B24MC-L8JTFx
2.5 V ±1.0% S-1122B25MC-L8KTFx
2.6 V ±1.0% S-1122B26MC-L8LTFx
2.7 V ±1.0% S-1122B27MC-L8MTFx
2.8 V ±1.0% S-1122B28MC-L8NTFx
2.9 V ±1.0% S-1122B29MC-L8OTFx
3.0 V ±1.0% S-1122B30MC-L8PTFx
3.1 V ±1.0% S-1122B31MC-L8QTFx
3.2 V ±1.0% S-1122B32MC-L8RTFx
3.3 V ±1.0% S-1122B33MC-L8STFx
3.4 V ±1.0% S-1122B34MC-L8TTFx
3.5 V ±1.0% S-1122B35MC-L8UTFx
3.6 V ±1.0% S-1122B36MC-L8VTFx
3.7 V ±1.0% S-1122B37MC-L8WTFx
3.8 V ±1.0% S-1122B38MC-L8XTFx
3.9 V ±1.0% S-1122B39MC-L8YTFx
4.0 V ±1.0% S-1122B40MC-L8ZTFx
4.1 V ±1.0% S-1122B41MC-L9ATFx
4.2 V ±1.0% S-1122B42MC-L9BTFx
4.3 V ±1.0% S-1122B43MC-L9CTFx
4.4 V ±1.0% S-1122B44MC-L9DTFx
4.5 V ±1.0% S-1122B45MC-L9ETFx
4.6 V ±1.0% S-1122B46MC-L9FTFx
4.7 V ±1.0% S-1122B47MC-L9GTFx
4.8 V ±1.0% S-1122B48MC-L9HTFx
4.9 V ±1.0% S-1122B49MC-L9ITFx
5.0 V ±1.0% S-1122B50MC-L9JTFx
5.1 V ±1.0% S-1122B51MC-L9KTFx
5.2 V ±1.0% S-1122B52MC-L9LTFx
5.3 V ±1.0% S-1122B53MC-L9MTFx
5.4 V ±1.0% S-1122B54MC-L9NTFx
5.5 V ±1.0% S-1122B55MC-L9OTFx
Remark 1. Please contact our sales office for type A products.
2. x: G or U
3. Please select products of environmental code = U for Sn 100%, halogen-free products.
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.6.0_00 S-1112/1122 Series
Seiko Instruments Inc. 7
Pin Configuration
Table 3 (S-1112 Series)
Pin No. Symbol Description
1 NC
*1 No connection
2 VSS GND pin
3 ON/OFF Shutdown pin
4 VIN Input voltage pin
SNT-6A(H)
Top view
1
2
3 4
6
5
5 VSS GND pin
6 VOUT Output voltage pin
Figure 2 *1. The NC pin is electrically open.
The NC pin can be connected to VIN or VSS.
Table 4
(S-1112 Series)
Pin No. Symbol Description
1 VIN Input voltage pin
2 VSS GND pin
3 ON/OFF Shutdown pin
4 NC*1 No connection
5 VOUT Output voltage pin
*1. The NC pin is electrically open.
The NC pin can be connected to VIN or VSS.
Table 5
5 4
1 3 2
SOT-23-5
Top view
(S-1122 Series)
Pin No. Symbol Description
Figure 3 1 VOUT Output voltage pin
2 VSS GND pin
3 VIN Input voltage pin
4 ON/OFF Shutdown pin
5 NC*1 No connection
*1. The NC pin is electrically open.
The NC pin can be connected to VIN or VSS.
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
8
Absolute Maximum Ratings
Table 6
(Ta = 25°C unless otherwise specified)
Item Symbol Absolute Maximum Rating Unit
VIN VSS − 0.3 to VSS + 7 V
Input voltage VON/OFF VSS − 0.3 to VIN + 0.3 V
Output voltage VOUT VSS − 0.3 to VIN + 0.3 V
SNT-6A(H) 500*1 mW
300 (When not mounted on board) mW
Power dissipation SOT-23-5 PD 600*1 mW
Operating ambient temperature Topr −40 to +85 °C
Storage temperature Tstg −40 to +125 °C
*1. When mounted on board
[Mounted board]
(1) Board size : 114.3 mm × 76.2 mm × t1.6 mm
(2) Board name : JEDEC STANDARD51-7
Caution The absolute maximum ratings are rated values exceeding w hich the product could suffer
physical damage. These values must therefore not be exceeded under any conditions.
050 100 150
700
500
0
Power dissi
p
ation
(
PD
)
[
mW
]
A
mbient tem
p
erature
(
Ta
)
[
°C
]
200
SOT-23-5
600
400
300
100
SNT-6A
(
H
)
Figure 4 Power Dissipation of The Package (When Mounted on Board)
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.6.0_00 S-1112/1122 Series
Seiko Instruments Inc. 9
Electrical Characteristics Table 7 (Ta = 25°C unless otherwise specified)
Item Symbol Conditions Min. Typ. Max. Unit
Test
Circuit
Output voltage*1 VOUT(E) V
IN = VOUT(S) + 1.0 V, IOUT = 30 mA VOUT(S)
× 0.99 VOUT(S)
VOUT(S)
× 1.01 V 1
Output current*2 IOUT V
IN ≥ VOUT(S) + 1.0 V 150*5 ⎯ ⎯ mA 3
Dropout voltage*3 Vdrop I
OUT = 100 mA 1.5 V ≤ VOUT(S) ≤ 1.6 V ⎯ 0.32 0.55 V 1
1.7 V ≤ VOUT(S) ≤ 1.8 V ⎯ 0.28 0.47 V 1
1.9 V ≤ VOUT(S) ≤ 2.3 V ⎯ 0.25 0.35 V 1
2.4 V ≤ VOUT(S) ≤ 2.7 V ⎯ 0.20 0.29 V 1
2.8 V ≤ VOUT(S) ≤ 5.5 V ⎯ 0.19 0.26 V 1
Line regulation OUTIN
OUT1
VVV
•
Δ
Δ VOUT(S) + 0.5 V ≤ VIN ≤ 6.5 V,
IOUT = 30 mA ⎯ 0.05 0.2 % / V 1
Load regulation ΔVOUT2 VIN = VOUT(S) + 1.0 V,
1.0 mA ≤ IOUT ≤ 80 mA ⎯ 12 40 mV 1
Output voltage
temperature coefficient*4 OUT
OUT
VTa
V
•Δ
Δ VIN = VOUT(S) + 1.0 V, IOUT = 10 mA,
−40°C ≤ Ta ≤ 85°C ⎯ ±100 ⎯ ppm/
°C 1
Current consumption
during operation ISS1 VIN = VOUT(S) + 1.0 V, ON/OFF pin = ON,
no load ⎯ 50 90 μA 2
Current consumption
during shutdown ISS2 VIN = VOUT(S) + 1.0 V, ON/OFF pin = OFF,
no load ⎯ 0.1 1.0 μA 2
Input voltage VIN ⎯ 2.0 ⎯ 6.5 V ⎯
Shutdown pin
input voltage “H” VSH V
IN = VOUT(S) + 1.0 V, RL = 1.0 kΩ 1.5 ⎯ ⎯ V 4
Shutdown pin
input voltage “L” VSL V
IN = VOUT(S) + 1.0 V, RL = 1.0 kΩ ⎯ ⎯ 0.3 V 4
Shutdown pin
input current “H” ISH V
IN = 6.5 V, VON/OFF = 6.5 V −0.1 ⎯ 0.1 μA 4
Shutdown pin
input current “L” ISL V
IN = 6.5 V, VON/OFF = 0 V −0.1 ⎯ 0.1 μA 4
Ripple rejection RR
VIN = VOUT(S) + 1.0 V, f = 1.0 kHz,
ΔVrip = 0.5 Vrms, IOUT = 30 mA ⎯ 80 ⎯ dB 5
Short-circuit current Ishort VIN = VOUT(S) + 1.0 V, ON/OFF pin = ON,
VOUT = 0 V ⎯ 200 ⎯ mA 3
*1. VOUT(S): Specified output voltage
VOUT(E): Actual output voltage at the fixed load
The output voltage when fixing IOUT(= 30 mA) and inputting VOUT(S) + 1.0 V
*2. The output current at which the output voltage becomes 95% of VOUT(E) after gradually increasing the output current.
*3. Vdrop = VIN1 − (VOUT3 × 0.98)
V
OUT3 is the output voltage when VIN = VOUT(S) + 1.0 V and IOUT = 100 mA.
VIN1 is the input voltage at which the output voltage becomes 98% of VOUT3 after gradually decreasing the input voltage.
*4. The change in temperature [mV/°C] is calculated using the following equation.
[] [] []
1000C/ppm
VTaV
VVC/mV
Ta
V OUT
OUT
OUT(S)
OUT ÷°
•Δ
Δ
×=°
Δ
Δ3*2*1*
*1. The change in temperature of the output voltage
*2. Specified output voltage
*3. Output voltage temperature coefficient
*5. The output current can be at least this value.
Due to restrictions on the package power dissipation, this value may not be satisfied. Attention should be paid to the
power dissipation of the package when the output current is large.
This specification is guaranteed by design.
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
10
Test Circuits
1.
VSS
VOUT
ON/OFF
Set to
power ON
VIN
V
A
+
+
Figure 5
2.
VSS
VOUT
ON/OFF
Set to
VIN or GND
VIN
A
+
Figure 6
3.
Set to
power ON
VSS
VOUT
ON/OFF
VIN
V
A
+
+
Figure 7
4.
VSS
VOUT
ON/OFF
VIN
A V RL
+ +
Figure 8
5.
VSS
VOUT
ON/OFF
VIN
V
Set to
Power ON
RL
+
Figure 9
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.6.0_00 S-1112/1122 Series
Seiko Instruments Inc. 11
Standard Circuit
ON/OFF
VSS
VOUTVIN
CIN
*1
CL
*2
Input Out
p
ut
GND
Sin
g
le GND
*1. C
IN is a capacitor for stabilizing the input.
*2. A ceramic capacitor of 0.47 μF or more can be used for CL.
Figure 10
Caution The above connection diagram and constant will not guarantee successful operation.
Perform thorough evaluation using the actual application to set the constant.
Application Conditions
Input capacitor (CIN): 1.0 μF or more
Output capacitor (CL): 0.47 μF or more
ESR of output capacitor: 10 Ω or less
Caution A general series regulator may oscillate, depending on the external components selected.
Check that no oscillation occurs with the application using the above capacitor.
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
12
Explanation of Terms
1. Low dropout voltage regulator
The low dropout voltage regulator is a voltage regulator whose dropout voltage is low due to its built-in
low on-resistance transistor.
2. Low ESR
A capacitor whose ESR (Equivalent Series Resistance) is low. The S-1112/1122 Series enables use of
a low ESR capacitor, such as a ceramic capacitor, for the output-side capacitor CL. A capacitor whose
ESR is 10 Ω or less can be used.
3. Output voltage (VOUT)
The accuracy of the output voltage is ensured at ±1.0% under the specified conditions of fixed input
voltage*1, fixed output current, and fixed temperature.
*1. Differs depending the product.
Caution If the above conditions change, the output voltage value may vary and exceed the
accuracy range of the output voltage. Please see the electrical characteristics and
attached characteristics data for details.
4.
V ΔV
ΔV
regulation Line OUTIN
OUT1 ⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
•
Indicates the dependency of the output voltage on the input voltage. That is, the values show how
much the output voltage changes due to a change in the input voltage with the output current remaining
unchanged.
5. Load regulation (ΔVOUT2)
Indicates the dependency of the output voltage on the output current. That is, the values show how
much the output voltage changes due to a change in the output current with the input voltage remaining
unchanged.
6. Dropout voltage (Vdrop)
Indicates the difference between the input voltage VIN1, which is the input voltage (VIN) at the point where
the output voltage has fallen to 98% of the output voltage value VOUT3 after VIN was gradually decreased
from VIN = VOUT(S) + 1.0 V, and the output voltage at that point (VOUT3 × 0.98).
Vdrop = VIN1 − (VOUT3 × 0.98)
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.6.0_00 S-1112/1122 Series
Seiko Instruments Inc. 13
7. ⎟
⎠
⎞
⎜
⎝
⎛
•Δ
Δ
OUT
OUT
V TaV
voltage output of tcoefficien eTemperatur
The shadowed area in Figure 11 is the range where VOUT varies in the operating temperature range
when the temperature coefficient of the output voltage is ±100 ppm/°C.
VOUT
(
E
)
*1
Ex. S-1112/1122B 2 8 Ty p .
−40 25
+
0.28 mV / °C
VOUT
[V]
*1. VOUT(E) is the value of the output voltage measured at 25°C.
85 Ta [°C]
−
0.28 mV / °C
Figure 11
A change in the temperature of the output voltage [mV/°C] is calculated using the following equation.
[] [] []
1000C/ppm
VTaV
VVC/mV
Ta
V OUT
OUT
OUT(S)
OUT ÷°
•
Δ
Δ
×=°
Δ
Δ3*
2*
1*
*1. Change in temperature of output voltage
*2. Specified output voltage
*3. Output voltage temperature coefficient
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
14
Operation
1. Basic operation
Figure 12 shows the block diagram of the S-1112/1122 Series.
The error amplifier compares the reference voltage (Vref) with Vfb, which is the output voltage resistance-
divided by feedback resistors Rs and Rf. It supplies the output transistor with the gate voltage necessary
to ensure a certain output voltage free of any fluctuations of input voltage and temperature.
Reference voltage
circuit
VOUT
*1
*1. Parasitic diode
VSS
VIN
Rs
R
f
Error
am plifier
Current
supply
Vref −
+
Vfb
Figure 12
2. Output transistor
The S-1112/1122 Series uses a low on-resistance P-channel MOS FET as the output transistor.
Be sure that VOUT does not exceed VIN + 0.3 V to prevent the voltage regulator from being damaged due
to inverse current flowing from VOUT pin through a parasitic diode to VIN pin.
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.6.0_00 S-1112/1122 Series
Seiko Instruments Inc. 15
3. Shutdown pin (ON/OFF pin)
This pin starts and stops the regulator.
When the ON/OFF pin is set to the shutdown level, the operation of all internal circuits stops, and the built-
in P-channel MOS FET output transistor between the VIN pin and VOUT pin is turned off to substantially
reduce the current consumption. The VOUT pin becomes the VSS level due to the internally divided
resistance of several MΩ between the VOUT pin and VSS pin.
The structure of the ON/OFF pin is as shown in Figure 13. Since the ON/OFF pin is neither pulled down
nor pulled up internally, do not use it in the floating state. In addition, note that the current consumption
increases if a voltage of 0.3 V to VIN – 0.3 V is applied to the ON/OFF pin. When the ON/OFF pin is not
used, connect it to the VSS pin if the logic type is “A” and to the VIN pin if it is “B”.
Table 8
Logic Type ON/OFF Pin Internal Circuits VOUT Pin Voltage Current Consumption
A “L”: Power on Operating Set value ISS1
A “H”: Power off Stopped VSS level ISS2
B “L”: Power off Stopped VSS level ISS2
B “H”: Power on Operating Set value ISS1
VSS
ON/OFF
VIN
Figure 13
Selection of Output Capacitor (CL)
The S-1112/1122 Series requires an output capacitor between the VOUT and VSS pins for phase
compensation. A ceramic capacitor with a capacitance of 0.47 μF or more can be used. Even if using an OS
capacitor, tantalum capacitor, or aluminum electrolytic capacitor, a capacitance of 0.47 μF or more and an ESR
of 10 Ω or less are required.
The value of the output overshoot or undershoot transient response varies depending on the value of the output
capacitor.
When selecting the output capacitor, perform sufficient evaluation, including evaluation of temperature
characteristics, on the actual device.
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
16
Precautions
• Wiring patterns for the VIN, VOUT and GND pins should be designed so that the impedance is low.
When mounting an output capacitor between the VOUT and VSS pins (CL) and a capacitor for stabilizing
the input between VIN and VSS pins (CIN), the distance from the capacitors to these pins should be as
short as possible.
• Note that the output voltage may increase when a series regulator is used at low load current (1.0 mA or
less).
• Generally a series regulator may cause oscillation, depending on the selection of external parts. The
following conditions are recommended for this IC. However, be sure to perform sufficient evaluation
under the actual usage conditions for selection, including evaluation of temperature characteristics.
Input capacitor (CIN): 1.0 μF or more
Output capacitor (CL): 0.47 μF or more
Equivalent series resistance (ESR): 10 Ω or less
• The voltage regulator may oscillate when the impedance of the power supply is high and the input
capacitor is small or an input capacitor is not connected.
• The application conditions for the input voltage, output voltage, and load current should not exceed the
package power dissipation.
• Do not apply an electrostatic discharge to this IC that exceeds the performance ratings of the built-in
electrostatic protection circuit.
• In determining the output current, attention should be paid to the output current value specified in Table
7 in the “ Electrical Characteristics” and footnote *5 of the table.
• 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.
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.6.0_00 S-1112/1122 Series
Seiko Instruments Inc. 17
Characteristics (Typical Data)
Remark The following, which describes the S-1112 Series as the typical product, shows typical data common
to the S-1122 Series.
(1) Output Voltage vs. Output current (when load current increases)
S-1112B15 (Ta = 25°C) S-1112B30 (Ta = 25°C)
VOUT [V]
0 100 200 300 400 500 600
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
VIN = 1.8 V
2.5 V
6.5 V
VOUT [V]
200 300 400 500
1000600
VIN = 3.3 V
4.0 V
6.5 V
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
IOUT [mA] IOUT [mA]
S-1112B50 (Ta = 25°C)
VOUT [V]
200 300 400
1000
VIN = 5.3 V
6.0 V
6.5 V
500
6
5
4
3
2
1
0600
IOUT [mA]
Remark In determining the output current, attention
should be paid to the following.
1) The minimum output current value
and footnote *5 in the “ Electrical
Characteristics”
2) The package power dissipation
(2) Output voltage vs. Input voltage
S-1112B15 (Ta = 25°C) S-1112B30 (Ta = 25°C)
VOUT [V]
1.6
1.5
1.4
1.3
1.2
1.1
1.0
IOUT = 1 mA
30 mA
50 mA
3.53.0
2.5 2.0 1.5 1.0
VOUT [V]
3.1
3.0
2.9
2.8
2.7
2.6
2.5
IOUT = 1 mA
30 mA
50 mA
5.04.5
4.0
3.53.02.5
VIN [V] VIN [V]
S-1112B50 (Ta = 25°C)
VOUT [V]
IOUT = 1 mA
30 mA 50 mA
5.5
5.0
4.5
4.0
3.5
3.0
2.5 7.06.0
5.0 4.0 3.0 2.0
VIN [V]
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
18
(3) Dropout voltage vs. Output current
S-1112B15 S-1112B30
Vdrop [V]
–40°C
25°C
85°C
0 50 100 150 200
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
Vdrop [V]
–40°C
25°C
85°C
0
50 100
150
200
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
IOUT [mA]
IOUT [mA]
S-1112B50
Vdrop [V]
25°C
0
50
100
150
200
–40°C
85°C
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
IOUT [mA]
(4) Dropout voltage vs. Set output voltage
Vdrop [V]
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
07
1 2 3 4 5 6 0
100 mA
150 mA
50 mA
30 mA
10 mA
VOTA [V]
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.6.0_00 S-1112/1122 Series
Seiko Instruments Inc. 19
(5) Output voltage vs. Ambient temperature
S-1112B15 S-1112B30
VOUT [V]
1.60
1.55
1.50
1.45
1.40
25
–25 75 100
–50 0 50
VOUT [V]
0 25
–50 –25 50 75 100
3.20
3.15
3.10
3.05
3.00
2.95
2.90
2.85
2.80
Ta [°C]
Ta [°C]
S-1112B50
VOUT [V]
100
75
50
25
0
–25
–50
5.3
5.2
5.1
5.0
4.9
4.8
4.7
Ta [°C]
(6) Current consumption vs. Input voltage
S-1112B15 S-1112B30
ISS1 [μA]
120
100
80
60
40
20
0 8
6
4 2
0
85°C 25°C
–
40°C
ISS1 [μA]
6
4
2
0
120
100
80
60
40
20
08
85°C
25°C
–
40°C
VIN [V]
VIN [V]
S-1112B50
ISS1 [μA]
0 2 4 6 8
120
100
80
60
40
20
0
25°C
–
40°C
85°C
VIN [V]
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
20
(7) Ripple rejection
S-1112B15 (Ta = 25°C) S-1112B30 (Ta = 25°C)
VIN = 2.5 V, COUT = 0.47 μF VIN = 4.0 V, COUT = 0.47 μF
Ripple Rejection [dB]
100 1k 10k 100k
10
IOUT = 1 mA
30 m
A
50 m
A
1M
100
80
60
40
20
0
Ripple Rejection [dB]
100 1k 10k 100k
10
IOUT = 1 mA
30 m
A
50 m
A
1M
100
80
60
40
20
0
Frequency [Hz]
Frequency [Hz]
S-1112B50 (Ta = 25°C)
VIN = 6.0 V, COUT = 0.47 μF
Ripple Rejection [dB]
100 1k 10k 100k
10
IOUT = 1 mA
30 m
A
50 m
A
1M
100
80
60
40
20
0
Frequency [Hz]
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
Rev.6.0_00 S-1112/1122 Series
Seiko Instruments Inc. 21
Reference Data
(1) Input transient response characteristics
S-1112B15 (Ta = 25°C) S-1112B30 (Ta = 25°C)
IOUT = 30 mA, tr = tf = 5.0 μs, COUT = 0.47 μF, CIN = 0 μF IOUT = 30 mA, tr = tf = 5.0 μs, COUT = 0.47 μF, CIN = 0 μF
VOUT [V]
1.62
1.60
1.58
1.56
1.54
1.52
1.50
1.48
1.46
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
V
IN
V
OUT
-40
-20
0
20
40
60 80
100
120
140
160
VIN [V]
VOUT [V]
-40 -20 020 40 60
80
100
120
140
160
VIN
VOUT
3.08
3.06
3.04
3.02
3.00
2.98
2.96
6
5
4
3
2
1
0
VIN [V]
t [μs] t [μs]
S-1112B50 (Ta = 25°C)
IOUT = 30 mA, tr = tf = 5.0 μs, COUT = 0.47 μF, CIN = 0 μF
VOUT [V]
5.12
5.10
5.08
5.06
5.04
5.02
5.00
4.98
4.96
8
7
6
5
4
3
2
1
0
VIN
VOUT
-40
-20
0
20
40
60 80
100
120
140
160
VIN [V]
t [μs]
(2) Load transient response characteristics
S-1112B15 (Ta = 25°C) S-1112B30 (Ta = 25°C)
VIN = 2.5 V, COUT = 0.47 μF, CIN = 1.0 μF, IOUT = 50↔100 mA VIN = 4.0 V, COUT = 0.47 μF, CIN = 1.0 μF, IOUT = 50↔100 mA
VOUT [V]
0
20
40
60 80
100
120
140
-40
-20
160
I
OUT
V
OUT
1.70
1.65
1.60
1.55
1.50
1.45
1.40
150
100
50
0
–50
–100
–150
IOUT [mA]
VOUT [V]
020 40 60
80
100
120
140
-40 -20 160
I
OUT
V
OUT
150
100
50
0
–50
–100
–150
3.20
3.15
3.10
3.05
3.00
2.95
2.90
IOUT [mA]
t [μs] t [μs]
S-1112B50 (Ta = 25°C)
VIN = 6.0 V, COUT = 0.47 μF, CIN = 1.0 μF, IOUT = 50↔100 mA
VOUT [V]
0
20
40
60 80
100
120
140
-40
-20
160
V
OUT
I
OUT
5.20
5.15
5.10
5.05
5.00
4.95
4.90
150
100
50
0
–50
–100
–150
IOUT [mA]
t [μs]
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-1112/1122 Series Rev.6.0_00
Seiko Instruments Inc.
22
(3) Shutdown pin transient response characteristics
S-1112B15 (Ta = 25°C) S-1112B30 (Ta = 25°C)
VIN = 2.5 V, COUT = 0.47 μF, CIN = 1.0 μF, IOUT = 100 mA VIN = 4.0 V, COUT = 0.47 μF, CIN = 1.0 μF, IOUT = 100 mA
VOUT [V]
VON/OFF
VOUT
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
-0.4 -0.2 1.6
3
2
1
0
–1
–2
–3
5
4
3
2
1
0
–1
VON/OFF [V]
VOUT [V]
00.2 0.4 0.6 0.8 1.0 1.2 1.4
-0.4 -0.2 1.6
VON/OFF
VOUT
6
4
2
0
–2
–4
–6
10
8
6
4
2
0
–2
VON/OFF [V]
t [ms] t [ms]
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
SNT-6A(H)-A-PKG Dimensions
PI006-A-P-SD-2.0
0.2±0.05
0.48±0.02
0.08 +0.05
-0.02
0.5
1.57±0.03
No. PI006-A-P-SD-2.0
12
3
4
5
6
Feed direction
4.0±0.1
2.0±0.05
4.0±0.1
ø1.5 +0.1
-0
ø0.5
1.85±0.05 0.65±0.05
0.25±0.05
5°
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
PI006-A-C-SD-1.0
SNT-6A(H)-A-Carrier Tape
No. PI006-A-C-SD-1.0
+0.1
-0
1
2
4
3
56
12.5max.
9.0±0.3
ø13±0.2
(60°) (60°)
QTY.
No. PI006-A-R-SD-1.0
PI006-A-R-SD-1.0
Enlarged drawing in the central part
No.
TITLE
SCALE
UNIT mm
Seiko Instruments Inc.
SNT-6A(H)-A-Reel
5,000
No.
TITLE
SCALE
UNIT mm
SNT-6A(H)-A-Land Recommendation
Seiko Instruments Inc.
PI006-A-L-SD-3.0
No. PI006-A-L-SD-3.0
0.3
0.20.3
0.20.3
0.52
1.36
0.52
Caution Making the wire pattern under the package is possible. However, note that the package
may be upraised due to the thickness made by the silk screen printing and of a solder
resist on the pattern because this package does not have the standoff.
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
www.sii-ic.com
• 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 approp riate governmental authority.
• Use of the information described herein for other purposes and/or reproduction or copying without the
express permissi on of Seiko Instruments Inc. is strictly prohibited.
• The products described herein cannot be used as part of any device or equipment affecting the human
body, such as exercise equipment, medical equipment, security systems, gas equipment, or any apparatus
installed in airplanes and other vehicle s, without prior written permission of Seiko Instruments Inc.
• Although Seiko Instruments Inc. exerts the greatest possible effort to ensure high quality and reliability, the
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
malfunction prevention, to prevent any accidents, fires, or comm unity damage that may ensue.