SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp/en/
SI-8001FFE
Description
The SI-8001FFE DC voltage regulator is a DC-to-DC buck
convertor that attains an oscillation frequency of 300 kHz,
and has an integrated miniaturized choke coil, allowing it to
serve as a small, high efficiency power supply in a compact
TO220F package.
The internal switching regulator function provides high
efficiency switching regulation without any need for adjustment.
The device requires only six external support components. The
optional soft start function requires an additional capacitor.
Optional on/off control can be performed using a transistor.
The SI-8001FFE includes overcurrent and overtemperature
protection circuits.
Applications include:
▪ DVD recorder
▪ FPD TV
▪ Telecommunications equipment
▪ Office automation equipment, such as printers
▪ On-board local power supply
▪ Output voltage regulator for second stage of SMPS
(switched mode power supply)
Features and Benefits
▪ 3.5 A output current supplied in a small, through-hole
mount power package
▪ High efficiency: 83% at VIN
= 15 V, IO
= 2.0 A,VO
= 5 V
▪ Requires only six external components (optional soft
start requires an additional capacitor)
▪ Oscillation circuit built-in (frequency 300 kHz typical)
▪ Constant-current mode overcurrent protection circuit and
overtemperature protection circuit built-in
▪ Soft start function built-in (can be implemented as an
on/off function; output-off state at low level)
▪ Low current consumption during output-off state
DC-to-DC Step-Down Converter
Package: TO220F-5
Not to scale
Functional Block Diagram
Latch and
Driver
Overcurrent
Protection
Overtemperature
Protection
Reference
Voltage
Osc
Reset
Comparator
Error
Amplifier
VIN 1
3
4
2VOUT
Di C2
C1
GND
ADJ
SW
IN
R1
R2
L1
PReg
On/Off
Soft Start
5
C3
SS
Di
RK-46
(Sanken)
27469.057
2
SANKEN ELECTRIC CO., LTD.
DC-to-DC Step-Down Converter
SI-8001FFE
27469.057
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.
Selection Guide
Part Number Output Voltage
Adjustable Range
(V)
Efficiency,
Typ.
(%)
Input Voltage,
Max.
(V)
Output Current,
Max.
(A) Packing
SI-8001FFE 0.8 to 24 83 40 3.5 50 pieces per tube
Absolute Maximum Ratings
Characteristic Symbol Remarks Rating Units
DC Input Voltage VIN 43 V
Power Dissipation
PD1-1
Connected to infinite heatsink; TJ(max) = 150°C, limited by internal
overtemperature protection. 22.7 W
PD1-2 Connected to infinite heatsink; TJ = 125°C. 18.2 W
PD2-1
No heatsink; TJ(max) = 150°C, limited by internal overtemperature
protection. 2.15 W
PD2-2 No heatsink; TJ = 125°C. 1.72 W
Junction Temperature TJ
Internal overtemperature protection circuit may enable when TJ ≥
130°C. During product operation, recommended TJ ≤ 125°C. –40 to 150 °C
Storage Temperature Tstg –40 to 150 °C
Thermal Resistance (junction-to-case) RJC 5.5 °C/W
Thermal Resistance (junction-to-ambient air) RJA 58 °C/W
Recommended Operating Conditions*
Characteristic Symbol Remarks Min. Max. Units
DC Input Voltage Range VIN VIN (min) is the greater of 4.5 V or VO+3 V. See
remarks 40 V
DC Output Voltage Range VO0.8 24 V
DC Output Current Range IO
VIN ≥ VO + 3 V; to be used within the allowable package
power dissipation characteristics (refer to Power Dissipation
chart).
0 3.5 A
Operating Junction Temperature Range TJOP –30 125 °C
Operating Temperature Range TOP
To be used within the allowable package power dissipation
characteristics (refer to Power Dissipation chart). –30 85 °C
*Required for normal device functioning according to Electrical Characteristics table.
3
SANKEN ELECTRIC CO., LTD.
DC-to-DC Step-Down Converter
SI-8001FFE
27469.057
SI-8000FFE
(a)
V
O
on/off
control only
(c)
V
O
on/off and
soft start control
(b)
Soft start
only
C3
SS
5
SI-8000FFE
SS
5
SI-8000FFE
SS
5
System
TTL
C3
System
TTL
Terminal List Table
Name Number Function
IN 1 Supply voltage
SW 2 Regulated supply output
GND 3 Ground terminal
ADJ 4 Terminal for resistor bridge feedback
SS 5
The SS terminal is used to enable soft start and to control on/off operation of the IC output,
VO (see figure 2). If neither soft start nor on/off control is used, leave pin open.
To enable soft start, connect a capacitor between SS and ground. To control on/off
operation, connect an NPN bipolar transistor, in a TTL open collector output configuration,
between the SS terminal and GND. Turn off is done by decreasing VSSL below its rated
level.
When both soft start and VO on/off are used, a protection measure such as current limiting
is required because, if the capacitance of C3 large, the discharge current of C3 flows
across the transistor for on/off operation. Because a pull-up type resistor is provided inside
the IC, no external voltage can be applied.
Pin-out Diagram
Figure 2. Alternative configurations for SS pin. If neither soft start nor VO on/off is required, the SS pin is left open.
ELECTRICAL CHARACTERISTICS1, valid at TA = 25°C, VO = 5 V (adjusted), R1 = 4.2 kΩ, R1 = 0.8 kΩ
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Reference Voltage VADJ VIN = 15 V, IO = 0.2 A 0.784 0.800 0.816 V
Reference Voltage Temperature Coefficient ∆VADJ
/∆TV
IN = 15 V, IO = 0.2 A, TC = 0 to 100 °C – ±0.1 – mV/°C
Efficiency2ηVIN = 15 V, IO = 2 A – 83 – %
Operating Frequency fOVIN = 15 V, IO = 2 A 270 300 330 kHz
Line Regulation VLine VIN = 10 to 30 V, IO = 2 A – – 80 mV
Load Regulation VLoad VIN = 15 V, IO = 0.2 to 3.5 A – – 50 mV
Overcurrent Protection Threshold Current ISVIN = 15 V 3.6 – – A
SS Terminal On/Off Operation Threshold Voltage VSSL – – 0.5 V
SS Terminal On/Off Operation Outflow Current ISSL VSSL = 0 V – 6 30 μA
Quiescent Current 1 IqVIN = 15 V, IO = 0 A – 6 – mA
Quiescent Current 2 Iq(off) VIN = 15 V, VSS = 0 V – 200 600 μA
1Using circuit shown in Typical Application Circuit diagram.
2Efficiency is calculated as: η(%) = ([VO × IO] × [VIN × IIN]) × 100.
123 45
4
SANKEN ELECTRIC CO., LTD.
DC-to-DC Step-Down Converter
SI-8001FFE
27469.057
90
85
80
75
70
65
60
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
I
O
(A)
η (%)
6.00
5.00
4.00
3.00
2.00
1.00
0
5.10
5.08
5.06
5.04
5.02
5.00
4.98
4.96
4.94
4.92
4.90
012345678
V
O
(V)
Efficiency versus
Output Current
V
O
= 3.3 V
Efficiency versus
Output Current
V
O
= 5.0 V
Efficiency versus
Output Current
V
O
= 12.0 V
Low Voltage
Behavior:
Output Voltage
versus
Supply Voltage
8
V
15
V
40
V
30
V
20
V
01 23
Load Regulation:
Output Voltage
versus
Output Current
V
O
(V)
I
O
(A)
0
2
4
8
6
10
0 10203040
Quiescent Current
versus
Supply Voltage
I
O
= 0 A
SS pin open
I
q
(mA)
V
IN
(V)
V
IN
(V)
V
IN
100
95
90
85
80
75
70
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
I
O
(A)
η (%)
8
V15
V
40
V
30
V
20
V
V
IN
I
O
V
IN
0
A
0.5
A
1
A
40
V
30
V
15
V
10
V
8
V
2
A
3.5
A
90
85
80
75
70
65
60
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
I
O
(A)
η (%)
15V
40
V
30
V
20
V
V
IN
V
IN
15
V
8
V
30
V
40
V
Behavior at
Turn-Off:
Quiescent Current
versus
Input Voltage
I
O
= 0 A
V
SS
= 0 V
0
2
1
3
5
4
6
0123 54
Overcurrent
Protection:
Output Voltage
versus
Output Current
V
O
(V)
I
O
(A)
400
300
200
100
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
V
IN
(V)
I
Q
(μA)
Performance Characteristics
At TA = 25°C, VO = 5 V Adjusted, R1 = 4.2 kΩ, R2 = 0.8 kΩ
5
SANKEN ELECTRIC CO., LTD.
DC-to-DC Step-Down Converter
SI-8001FFE
27469.057
Thermal Performance Characteristics
24
22
20
18
16
14
12
10
8
6
4
2
0
–40 –20 0 20 40 60 80
Power Dissipation versus Ambient Temperature
Shin Etsu G746 silicon grease
P
D
(W)
T
A
(°C)
No heat sink
T
J
(max) = 125°C
No heat sink
T
J
(max) = 150°C
Al heat sink
75 mm × 75 mm × 2 mm
R
θJA
= 7.6°C/W
T
J
(max) = 125°C
Al heat sink
100 mm × 200 mm × 2 mm
R
θJA
= 5.2°C/W
T
J
(max) = 125°C
Al heat sink
200 mm × 200 mm × 2 mm
R
θJA
= 2.3°C/W
T
J
(max) = 125°C
Infinite heat sink
T
J
(max) = 150°C
Infinite heat sink
T
J
(max) = 125°C
6
5
4
3
2
1
0
0 20 40 60 80 100 120 140 180160
T
J
(°C)
V
O
(V)
Overtemperature
Protection:
Output Voltage versus
Junction Temperature
V
IN = 15 V, IO = 10 mA
OTP On
OTP Off
The application must be designed to ensure that the TJ(max)
of the device is not exceeded during operation. To do so, it is
necessary to determine values for maximum power dissipation,
PD(max), and ambient temperature, TA(max).
PD can be calculated from input values:
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛−⋅−
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛−⋅=
IN
O
OF
x
OOD
V
V
IVIVP 11
100
H
where:
VO is output voltage in V,
VIN is input supply voltage in V,
IO is output current in A,
ηx is IC efficiency in percent (varies with VIN and IO; refer to
efficiency performance curves for value), and
VF is forward voltage for the input diode, Di. In these tests, the
Sanken RK46 was used, at 0.5 V and IO = 3.5 A. For application
design, obtain thermal data from the datasheet for the diode.
PD is substantially affected by the heat conductance properties of
the application, in particular any heatsink connected to the device
radiation fin. The relationships of PD, TA, and heatsink type is
represented in the Power Dissipation chart.
Because the heat dissipation capacity of the heatsink depends
substantively on how it is used in the actual application, thermal
characteristics of the application must be confirmed by testing.
The internal overtemperature protection circuit may enable when
TJ ≥ 130°C.
6
SANKEN ELECTRIC CO., LTD.
DC-to-DC Step-Down Converter
SI-8001FFE
27469.057
Component Selection
VIN 1
GND GND
2
4
3
GNDSS
IN SW
ADJ
C1 C2
L1
Di
VO
R1
R2
IADJ
5
C3
Soft Start Only
SI-8001FFE
Component Rating
C1 470 μF
C2 680 μF
C3 0.1 μF (For soft start function)
Di RK-46 (Sanken)
L1 47 μH
Diode Di A Schottky-barrier diode must be used for Di. If other
diode types are used, such as fast recovery diodes, the IC may be
destroyed because of the reverse voltage applied by the recovery
voltage or ON voltage.
Choke Coil L1 If the winding resistance of the choke coil is too
high, the efficiency may be reduced below rating. Because the
overcurrent protection start current is approximately 4.2 A, atten-
tion must be paid to the heating of the choke coil by magnetic
saturation due to overload or short-circuited load.
Capacitors C1, C2, and C3 Because for SMPS, large ripple
currents flow across C1 and C2, capacitors with high frequency
and low impedance must be used. If the impedance of C2 is too
high, the switching waveform may not be normal at low tempera-
tures. Do not use either OS or tantalum types of capacitors for
C2, because those cause an abnormal oscillation.
C3 is required only if the soft start function is used. If not using
soft-start, leave the SS terminal open. A pull-up resistor is pro-
vided inside the IC.
Resistor Bridge R1 and R2 comprise the resistor bridge for the
output voltage, VO, and are calculated as follows:
()()
) , and
(()
Ω
×
===Ω
×
−
=
−
=
−−
k
I
V
R2
V
IVV
R1
ADJ
ADJO
ADJ
ADJO
8.0
1018.0
1018.0
33
IADJ should always be set to 1 mA. Note that R2 should always be
present to ensure stable operation, even if VO, is set to 0.8 V (that
is, even if there is no R1). VO should be at least VIN + 8%.
R1
R2
GND
L1
C1 C2
U1 C3 S1
D1
Vin
Vsw
Vout
Vadj/Vos
R1
R2
L1
GNDGND
C3 S1
Vadj/Vos
Vout
Vsw
D1
Vin
C1 C2
U1
GND
All external components should be mounted as close as possible
to the SI-8001FFE. The ground of all components should be
connected at one point.
Recommended PCB Layout
Typical Application Diagram
7
SANKEN ELECTRIC CO., LTD.
DC-to-DC Step-Down Converter
SI-8001FFE
27469.057
2.54 ±0.2
0.7
15. 87 ±0.2
5. 4
3. 3 ± 0. 1
6. 68 ± 0. 2
2.76 ±0.2
7
10.16 ± 0.2
4.7±0.2
Φ
3.2±0.2
0.6 +0.1
-0.05
0.8
(2)
4.3 ±0.7
8.2 ±0.7
4 x 1.7±0.6 = (6.8) 0.5 +0.2
-0.1
(4-R1)
R-end
(17.9)
4. 3 ± 0. 6
Branding
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
Leadform: 1113A
Weight: 2.3 g typical
Dimensions in millimeters
Branding codes (exact appearance at manufacturer discretion):
1st line, type: 8001FFE
2nd line, lot: SK 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 5)
3rd line, tracking number: nnnn
PACKAGE OUTLINE DRAWING
RoHS directive compliant
Device pins lead (Pb) free
Leadframe: 1113A
8
SANKEN ELECTRIC CO., LTD.
DC-to-DC Step-Down Converter
SI-8001FFE
27469.057
Because reliability can be affected adversely by improper
storage environments and handling methods, please observe
the following cautions.
Cautions for Storage
• Ensure that storage conditions comply with the standard
temperature (5°C to 35°C) and the standard relative
humidity (around 40% to 75%); avoid storage locations
that experience extreme changes in temperature or
humidity.
• Avoid locations where dust or harmful gases are present
and avoid direct sunlight.
• Reinspect for rust on leads and solderability of the
products that have been stored for a long time.
Cautions for Testing and Handling
When tests are carried out during inspection testing and
other standard test periods, protect the products from
power surges from the testing device, shorts between
the product pins, and wrong connections. Ensure all test
parameters are within the ratings specified by Sanken for
the products.
Remarks About Using Silicone Grease with a Heatsink
• When silicone grease is used in mounting the products on
a heatsink, it shall be applied evenly and thinly. If more
silicone grease than required is applied, it may produce
excess stress.
• Volatile-type silicone greases may crack after long periods
of time, resulting in reduced heat radiation effect. Silicone
greases with low consistency (hard grease) may cause
cracks in the mold resin when screwing the products to a
heatsink.
Our recommended silicone greases for heat radiation
purposes, which will not cause any adverse effect on the
product life, are indicated below:
Type Suppliers
G746 Shin-Etsu Chemical Co., Ltd.
YG6260 Momentive Performance Materials Inc.
SC102 Dow Corning Toray Co., Ltd.
Cautions for Mounting to a Heatsink
• When the flatness around the screw hole is insufficient, such
as when mounting the products to a heatsink that has an
extruded (burred) screw hole, the products can be damaged,
even with a lower than recommended screw torque. For
mounting the products, the mounting surface flatness should
be 0.05 mm or less.
• Please select suitable screws for the product shape. Do not
use a flat-head machine screw because of the stress to the
products. Self-tapping screws are not recommended. When
using self-tapping screws, the screw may enter the hole
diagonally, not vertically, depending on the conditions of hole
before threading or the work situation. That may stress the
products and may cause failures.
• Recommended screw torque: 0.588 to 0.785 N●m (6 to 8
kgf●cm).
• For tightening screws, if a tightening tool (such as a driver)
hits the products, the package may crack, and internal
stress fractures may occur, which shorten the lifetime of
the electrical elements and can cause catastrophic failure.
Tightening with an air driver makes a substantial impact.
In addition, a screw torque higher than the set torque can
be applied and the package may be damaged. Therefore, an
electric driver is recommended.
When the package is tightened at two or more places, first
pre-tighten with a lower torque at all places, then tighten
with the specified torque. When using a power driver, torque
control is mandatory.
Soldering
• When soldering the products, please be sure to minimize
the working time, within the following limits:
260±5°C 10±1 s (Flow, 2 times)
380±10°C 3.5±0.5 s (Soldering iron, 1 time)
• Soldering should be at a distance of at least 2.0 mm from
the body of the products.
Electrostatic Discharge
• When handling the products, the operator must be
grounded. Grounded wrist straps worn should have at
least 1 MΩ of resistance from the operator to ground to
prevent shock hazard, and it should be placed near the
operator.
• Workbenches where the products are handled should be
grounded and be provided with conductive table and floor
mats.
• When using measuring equipment such as a curve tracer,
the equipment should be grounded.
• When soldering the products, the head of soldering irons
or the solder bath must be grounded in order to prevent
leak voltages generated by them from being applied to the
products.
• The products should always be stored and transported in
Sanken shipping containers or conductive containers, or
be wrapped in aluminum foil.
9
SANKEN ELECTRIC CO., LTD.
DC-to-DC Step-Down Converter
SI-8001FFE
27469.057
• 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.