SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp/en/
SPI-8003TW
Description
Designed to meet high-current requirements at high efficiency
in industrial and consumer applications; embedded core,
memory, or logic supplies; TVs, VCRs, and office equipment,
the SPI-8003TW DC-to-DC step-down (buck) converter offers
a variable 200 to 400 kHz switching frequency essential for
small external components. The N-channel high-current FET
is included on the die along with the oscillator, control, and
logic circuitry.
A wide input voltage range and integrated thermal and
overcurrent protection enhance overall system reliability.
Reference accuracy and excellent temperature characteristics
are provided. A chip-enable input gives the designer complete
control over power-up, standby, or power-down.
This device is supplied in a 16 lead surface-mount plastic
SOIC with exposed pad to provide a low-resistance path for
maximum power dissipation, low junction temperature, and
improved reliability.
Applications include:
▪ TVs, VCRs, and electronic games
▪ Embedded core, memory, or logic supplies
▪ Printers and other office equipment
▪ Industrial machinery
Features and Benefits
▪ Input range to 38 V
▪ Adjustable 1 to 24 V output range
▪ 1% output voltage tolerance
▪ Output current to 1.5 A
▪ Foldback current Limiting
▪ 200 to 400 kHz switching frequency
▪ 1.0 μA maximum standby current
▪ 1.0 V feedback reference voltage
▪ Soft start avoids supply voltage dip
▪ Remote voltage sensing
▪ Exposed pad for superior heat dissipation
▪ Thermal protection
Dual 1.5 A DC-to-DC Step-Down Converter
Pin-out Diagram
Package: 16 pin SOIC
Not to scale
27469.303DS
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
AGND
VIN1
VCC
SWOUT1
DGND1
SS1
VREF1
COSC
VIN2
C/E
SWOUT2
DGND2
SS2
VREF2
ROSC
AGND
+
–
+
–
PWM
LOGIC
PWM
LOGIC
1 V
2
SANKEN ELECTRIC CO., LTD.
Dual 1.5 A DC-to-DC Step-Down Converter Title
SPI-8003TW
27469.303DS
Selection Guide
Part Number Package Packing*
SPI-8003TW-TL SOIC-16 surface mount 1400 pieces reel
*Contact Allegro for additional packing options
All performance characteristics given are typical values for circuit or
system baseline design only and are at the nominal operating voltage and
an ambient temperature, TA, of 25°C, unless oth er wise stated.
Recommended Operating Conditions
Characteristic Symbol Notes Min Max Units
Dc Input Voltage VI
The recommended maximum value is
38 V when the output value is more than
4.75 V, derated linearly to 8 V when the
output is 1 V.
VO + 3 38 V
Dc Input Voltage VCC 4.5 38 V
Dc Output Current IO0 1.5 A
Dc Output Voltage VO124V
Operating Junction Temperature TJOP –30 125 °C
ABSOLUTE MAXIMUM RATINGS
Characteristic Symbol Notes Rating Units
Input Voltage VI, VCC
,
VCE
40 V
Junction Temperature TJ150 °C
Storage Temperature Range Tstg –40 to 150 °C
3
SANKEN ELECTRIC CO., LTD.
Dual 1.5 A DC-to-DC Step-Down Converter Title
SPI-8003TW
27469.303DS
FUNCTIONAL BLOCK DIAGRAM
Allowable Package Power Dissipation
DGND2
AGND
VCC
SS1
C/E
SWout1
VREF1
Start VREF OSC
RESET
SS2
SWout2
VREF2
VIN2
DGND1
PReg fdown TSD UVL
O
3V
Drive
PWM
Logic
PWM
Amp
Buffer-
Amp
OCP
3V
Drive
PWM
Logic
PWM
Amp
Buffer-
Amp
OCP
3V
1V
VIN1
fdown
cut
VIN
VO1
VO2
VC/E
C1 C4
R5
C5
R6
C6
L1
Di1
C2 C7
L2
Di2 C3 C8
R1
R2
R3
R4
15
6
7
12
11
1,9
13
14
16
5
4
2
3SPI-8003TW
AGND
AGND
fdown
cut
Cosc
10 Rosc
8
C9
R7
4
SANKEN ELECTRIC CO., LTD.
Dual 1.5 A DC-to-DC Step-Down Converter Title
SPI-8003TW
27469.303DS
ELECTRICAL CHARACTERISTICS, a valid at TA= 25°C
Characteristic Symbol Test conditions Min. Ttp. Max. Units
Reference Voltage VREF VIN=14 V, IO=0.1 A 0.996 1.006 1.016 V
Reference Voltage Temperature Coefficient ∆VREF/∆TV
IN=14 V, IO=0.1 A,TA= –30°C to 125°C – ±0.1 – mV/°C
Efficiency 1bEff1 VIN=VCC=14 V,VO= 5 V,IO= 0.5 A, IIN includes ICC –78– %
Efficiency 2bEff2 VIN=14 V, VO =5 V,IO= 0.5 A,VCC =5 V, IIN does
not include ICC
–81– %
Operating Frequency Range fOSC VIN=14 V, IO= 0.1 A, COSC= 100 pF 200 – 400 kHz
Line Regulation VLine VIN=VCC= 9 to 18 V, VO= 5 V, IO = 1 A – 30 60 mV
Load Regulation VLoad VIN= VCC=14 V, VO = 5 V, IO= 0.2 to1.5 A – 10 40 mV
Overcurrent Protection Starting Current ISVIN= VCC=14 V 1.6 – – A
Quiescent Current 1 IIN VIN= 14 V, VCC= 5 V, IO= 0 A,VO ≤12 V – 4 – mA
Quiescent Current 2 ICC VCC= 14 V, IO= 0 A – 8.5 – mA
Quiescent Current 3 IIN(off) VIN= 14 V, VC/E = low or open – – 1 μA
Quiescent Current 4 ICC(off) VCC= 14 V, VC/E = low or open – – 1 μA
Quiescent Current 5 IIN(SS0V) VIN= 14 V, VCC= 5 V, IO= 0 A, SS1= SS2 = 0 V – 4 – mA
Quiescent Current 6 ICC(SS0V) VCC= 14 V, IO= 0 A, SS1=SS2= 0 V – 8.5 – mA
C/E Terminal High Level Voltage VC/E(H) VIN=VCC= 14 V – 2.0 – V
C/E Terminal Low Level Voltage VC/E(L) VIN=VCC= 14 V – – 0.8 V
C/E Terminal Inflow Current At High Level Voltage IC/E(H) VC/E = 20 V – 95 – μA
SSx Terminal Low Level VoltagecVSSL VIN= VCC= 14 V – – 0.5 V
SSx Terminal Outflow Current at Low Level Voltage ISSL VSSL = 0 V, VIN = VCC = 14 V – 60 80 μA
aElectrical characteristics indicate specific limits, which are guaranteed when IC is operated under the measurement conditions shown in the Test
Circuit diagram, below.
bEfficiency is calculated by the following equation: η (%) = [(VO×IO) / (VIN×IIN)]×100 .
cTerminals 6 and 12, SS1 and SS2, are used to enable soft start by connecting a capacitor. The output can be turned on and off by using a SSx termi-
nal. The output is stopped by decreasing the SSx terminal voltage below VSSL . In order to perform ON/OFF operation of VO, it is required to connect an
NPN transistor or the output of an open collector type TTL transistor between SS1 or SS2 terminals and AGND. In case both soft start and VO ON/OFF
are used, a protection measure such as limitation of current is required, because the discharge current of C4 and C5 (see Typical Application diagram,
page 7) flows across a transistor for ON/OFF operation, if the capacitance of C4 and C5 is large. Because a pull-up type resistor is provided inside the
IC, no external voltage can be applied.
Test Circuit
SPI-8003TW
AGND
DGND1
VIN1
VIN2
VCC
SS1
SS2
C/E
DGND2
SWout1
SWout2
VREF1
VREF2
Ch1
Ch2
VSS2
VSS1
ISS2
ISS1
VREF1
VREF2
IIN
VIN
ICC
VCC
IC/E
VC/E
VO1
VO2
IO1
IO2
1,9
2
6
5
16
12
13
315
4
7
14
11
C1
C2
C3
C6
Di1
Di2
L1
L2
C7
C8
R1
R2
R3
R4 RL2
RL2
frequency
counter
Rosc
10 8
Cosc
C9
R7
5
SANKEN ELECTRIC CO., LTD.
Dual 1.5 A DC-to-DC Step-Down Converter Title
SPI-8003TW
27469.303DS
Efficiency Efficiency
Load Regulation
Low-Voltage Behavior
Load Regulation
TYPICAL CHARACTERISTICS
(TA = 25°C)
6
SANKEN ELECTRIC CO., LTD.
Dual 1.5 A DC-to-DC Step-Down Converter Title
SPI-8003TW
27469.303DS
TYPICAL CHARACTERISTICS (cont.)
(TA = 25°C)
Overcurrent Protection
Soft-Start Current Chip Enable Control Voltage
Overcurrent Protection
7
SANKEN ELECTRIC CO., LTD.
Dual 1.5 A DC-to-DC Step-Down Converter Title
SPI-8003TW
27469.303DS
Output Voltage Adjustable Resistors (R1, R2, R3,
and R4). The output voltages are adjusted by R1 and R3.
1000 for R2 and R4 is recommended.
R1 = (VO1 – Vref)/(Vref/R2)
R3 = (VO2 – Vref)/(Vref/R4)
Soft Start Capacitors (C5 and C6). Soft start for each
converter channel is enabled by connecting a capacitor
between terminal 6 and/or 12 and ground. The channel
may be turned off by decreasing the terminal 6 and/or 12
voltage below 0.5 V with either an npn small-signal tran-
sistor or the output of open-collector TTL. If both a large
soft-start capacitor and on/off control are desired, collec-
tor current limiting (R5 and R6) must be used to prevent
transistor damage. No external voltage can be applied to
terminal 6 or 12.
Input Capacitors (C1 and C4). Capacitors with low
impedance for high-frequency ripple current must be used.
Output Capacitors (C2, C3, C7, and C8). Capacitors
with low impedance for high-frequency ripple current
must be used. Especially when the C2 and C3 impedance
is high, the switching waveform may not be normal at low
temperatures. Film or tantalum capacitors for C2 and C3
may cause abnormal oscillations.
Catch Diodes (D1 and D2). Diode D1 and D2 must be
Schottky diodes. Other diode types will result in increased
forward voltage spikes, reverse current fl ow, increased
IC power dissipation during the off period, and possible
destruction of the IC.
Choke Coils (L1 and L2). If the winding resistance
of the choke coil is too high, the circuit effi ciency will
decrease. As the overcurrent protection start current is
approximately 2 A, attention must be paid to the heating of
the coil by magnetic saturation due to overload. To reduce
the output ripple, the inductor may be increased at the
expense of excessive board area and cost.
APPLICATIONS INFORMATION
Typical Application
SPI-8003TW
AGND
DGND1
VIN1
VIN2
VCC
SS1
SS2
C/E
DGND2
SWout1
SWout2
VREF1
VREF2
Ch1
Ch2
1,9
2
6
5
16
12
13
315
4
7
14
11
C1
C2
C3
C4
Di1
Di2
L1
L2
C7
C8
R1
R2
R3
R4
VO1
VO2
VC/E
GND
VIN
GND
R5
C5
R6
C6
IREF1
IREF2
C1, 220 μF/50 V
C2, C3 470 μF/25 V
C4 0.1 μF/50 V
C5, C6 1 uF/10 V
C7, C8 0.1 μF/50 V
C9 100 pF/10 V
L1, L2 47 μH
R2, R4 1 kΩ
R5, R6 1 kΩ
R7 30 kΩ
COSC ROSC
108
C9 R7
8
SANKEN ELECTRIC CO., LTD.
Dual 1.5 A DC-to-DC Step-Down Converter Title
SPI-8003TW
27469.303DS
APPLICATIONS INFORMATION (cont.)
Overcurrent Protection. The SPI-8000TW series has
a built-in fold-back type overcurrent protection circuit,
which limits the output current at a start-up mode. It thus
cannot be used in applications that require current at the
start-up mode such as:
(1) constant-current load,
(2) power supply with positive and negative outputs to
common load (a center-tap type power supply), or
(3) raising the output voltage by putting a diode or a resis-
tor between the device ground and system ground.
Determination of DC Input Voltage. The minimum
value of DC input voltage is VO + 3 V. The recommended
maximum value is 38 V when the output value is more
than 4.75 V, derated linearly to 8 V when the output is 1 V.
Layout Guideline
Parallel Operation. Parallel operation to increase load
current is not permitted.
Thermal Protection. Circuitry turns off the device
when the junction temperature rises above 135°C. It is
intended only to protect the device from failures due to
excessive junction temperatures and should not imply that
output short circuits or continuous overloads are permitted.
Heat Radiation and Reliability. The reliability of the
IC is directly related to the junction temperature (TJ) in its
operation. Accordingly, careful consideration should be
given to heat dissipation.
The inner frame on which the integrated circuit is mounted
is connected to the exposed pad. Therefore, it is very ef-
fective for heat radiation to enlarge the copper area that
is connected to the pad. The graph on page 3 illustrates
the effect of the copper area on the junction-to-ambient
thermal resistance (RJA).
The junction temperature (TJ) can be determined from
either of the following equations:
TJ = (PD × RJA) + TA
or
TJ = (PD × RJL) + TL
where PD = IO1(VI1 – VO1) + IO2(VI2 – VO2) + VCCICC and
R
JL = 9°C/W.
1
C4
C1 L1
Di1
C2
C7
R1 R3
R7
C9
R2 R4
C8
C3
Di2
L2
8
9
16
C/E
SS2
SS1
SPI-8003TW
9
SANKEN ELECTRIC CO., LTD.
Dual 1.5 A DC-to-DC Step-Down Converter Title
SPI-8003TW
27469.303DS
Product Weight: Approx. 0.859 g
Devices are lead (Pb) free.
Dimensions in Millimeters
Lead Temperature
(TL) Measured at
Terminal 1 or 9
View A
Recommended Land Pattern
Branding codes (exact appearance at manufacturer discretion):
1st line, type: 8003TW
2nd line, lot: YMW
where: Y is the last digit of the year of manufacture
M is the month (1 to 9, O, N, D)
W is the week of the month (1 to 6)
3rd line, tracking number: nnnnn
Branding Area
10
SANKEN ELECTRIC CO., LTD.
Dual 1.5 A DC-to-DC Step-Down Converter Title
SPI-8003TW
27469.303DS
• The contents in this document are subject to changes, for improvement and other purposes, without notice. Make sure that this is the
latest revision of the document before use.
• Application and operation examples described in this document are quoted for the sole purpose of reference for the use of the prod-
ucts herein and Sanken can assume no responsibility for any infringement of industrial property rights, intellectual property rights or
any other rights of Sanken or any third party which may result from its use.
• Although Sanken undertakes to enhance the quality and reliability of its products, the occurrence of failure and defect of semicon-
ductor products at a certain rate is inevitable. Users of Sanken products are requested to take, at their own risk, preventative measures
including safety design of the equipment or systems against any possible injury, death, fires or damages to the society due to device
failure or malfunction.
• Sanken products listed in this document are designed and intended for the use as components in general purpose electronic equip-
ment or apparatus (home appliances, office equipment, telecommunication equipment, measuring equipment, etc.).
When considering the use of Sanken products in the applications where higher reliability is required (transportation equipment and
its control systems, traffic signal control systems or equipment, fire/crime alarm systems, various safety devices, etc.), and whenever
long life expectancy is required even in general purpose electronic equipment or apparatus, please contact your nearest Sanken sales
representative to discuss, prior to the use of the products herein.
The use of Sanken products without the written consent of Sanken in the applications where extremely high reliability is required
(aerospace equipment, nuclear power control systems, life support systems, etc.) is strictly prohibited.
• In the case that you use Sanken products or design your products by using Sanken products, the reliability largely depends on the
degree of derating to be made to the rated values. Derating may be interpreted as a case that an operation range is set by derating the
load from each rated value or surge voltage or noise is considered for derating in order to assure or improve the reliability. In general,
derating factors include electric stresses such as electric voltage, electric current, electric power etc., environmental stresses such
as ambient temperature, humidity etc. and thermal stress caused due to self-heating of semiconductor products. For these stresses,
instantaneous values, maximum values and minimum values must be taken into consideration.
In addition, it should be noted that since power devices or IC's including power devices have large self-heating value, the degree of
derating of junction temperature affects the reliability significantly.
• When using the products specified herein by either (i) combining other products or materials therewith or (ii) physically, chemically
or otherwise processing or treating the products, please duly consider all possible risks that may result from all such uses in advance
and proceed therewith at your own responsibility.
• Anti radioactive ray design is not considered for the products listed herein.
• Sanken assumes no responsibility for any troubles, such as dropping products caused during transportation out of Sanken's distribu-
tion network.
• The contents in this document must not be transcribed or copied without Sanken's written consent.
