44 ICs
1-1-3 DC/DC Converter ICs
Parameter
Reference Voltage
Temperature Coefficient of Reference Voltage
Efficiency
Oscillation Frequency
Line Regulation
Load Regulation
Overcurrent Protection Starting Current
Low Level Voltage
SS Pin Outflow Current at Low Voltage
Quiescent Circuit Current
Features
• Compact full-mold package (equivalent to
TO220)
• Output current: 3.5 A
High efficiency: 83% (Vo = 5 V, V
IN
= 15 V, Io = 2 A)
• Requires only 6 discrete components
• Built-in reference oscillator (300 kHz)
• Built-in drooping-type overcurrent and thermal
protection circuits
• Built-in soft start circuit (Output ON/OFF
available)
Applications
• DVD recorder, FPD-TV
• OA equipment, such as printers
• Onboard local power supplies
Lineup
Part Number
Vo (V)
Io (A)
Function
SI-8001FFE
Variable(0.8 to 24)
3.5
Soft start
Unit
V
W
W
°C
°C
°C/W
°C/W
Symbol
VIN
PD1-1
PD1-2
PD2-1
PD2-2
Tj
Tstg
θj-c
θj-a
Parameter
Input Voltage
Power Dissipation
(With infinite heatsink)
Power Dissipation
(Without heatsink)
Junction Temperature*1
Storage Temperature
Thermal Resistance (Junction to Case)
Thermal Resistance (Junction to Ambient Air)
Absolute Maximum Ratings
Conditions
Limited by thermal protection circuit, Tj=150°C
Tj=125°C
Limited by thermal protection circuit, Tjmax=150°C
Tj=125°C
Recommended Operating Conditions
*: The minimum value of the input voltage range is 4.5 V or Vo +3 V, whichever is higher.
Parameter
Input Voltage Range
Output Voltage Range
Output Current Range
Operating Junction Temperature Range
Operating Temperature Range
Symbol
VIN
VO
IO
Tjop
Top
Unit
V
V
A
°C
°C
Ratings
SI-8001FFE
Vo+3*1 to 40
0.8 to 24
0 to 3.5
–30 to +125
–30 to +85
*: This product has built-in thermal protection circuits that may activate when the junction temperature exceeds 130°C.
The recommended design for the junction temperature during IC operation is below 125°C.
Ratings
SI-8001FFE
43
22.7
18.2
2.15
1.72
+150
–40 to +150
5.5
58
Symbol
VADJ
Conditions
VADJ/T
Conditions
η
Conditions
fo
Conditions
VOLINE
Conditions
VOLOAD
Conditions
IS
Conditions
VSSL
ISSL
Conditions
Iq
Conditions
Iq(OFF)
Conditions
Electrical Characteristics
Unit
V
mV/ °C
%
kHz
mV
mV
A
V
µA
mA
µA
(R1=4.2k, R2=0.8k when Ta=25°C and Vo=5V)
Ratings
SI-8001FFE
min. typ. max.
0.784 0.800 0.816
VIN=15V, Io=0.2A
±0.1
VIN=15V, Io=0.2A, Tc=0 to 100°C
83
VIN=15V, Io=2A
270 300 330
VIN=15V, Io=2A
55 80
VIN=10 to 30V, Io=2A
15 50
VIN=15V, Io=0.2 to 3.5A
3.6
VIN=15V
0.5
630
VIN=15V, VSS=0V
6
VIN=15V, Io=0A
200 600
VIN=15V, Vss=0V
*: Pin 5 is the SS pin. Soft start at power on can be performed with a capacitor connected to
this pin. The output can also be turned ON/OFF with this pin.
The output is stopped by setting the voltage of this pin to VSSL or lower. SS-pin voltage
can be changed with an open-collector drive circuit of a transistor. When using both the
soft-start and ON/OFF functions together, the discharge current from C3 flows into the ON/
OFF control transistor. Therefore, limit the current securely to protect the transistor if C3
capacitance is large. The SS pin is pulled up (3.7 V typ.) to the power supply in the IC, so
applying the external voltage is prohibited. If this pin is not used, leave it open.
SI-8000FFE SI-8000FFE
SS5SS5SS
C3C3
5
V
O.
ON/OFF Soft start Soft start
+Vo. ON/OFF
SI-8000FFE
Full-Mold, Separate Excitation Step-down Switching Mode
SI-8000FFE Series
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45
ICs
SI-8000FFE Series
External Dimensions (TO220F-5) (Unit : mm)
Block Diagram
4
3
GND
2
IN
SS
SW
ADJ
1
5PReg.
Reset
OSC
+
Comp.
Error Amp.
Latch &
Drive
TSD
ON/OFF
Soft
start
+
+
V
REF
OCP
Typical Connection Diagram
C1:470µF
C2:680µF
C3:0.1µF(Only when using soft-start function)
L1:47µH
D1:RK46(Sanken)
IN
C
1
C
3
Di
L1
R1
R2 C
2
V
IN
GNDSS
GND
SI-8001FFE
SW
I
ADJ
ADJ
12
4
35
++
V
OUT
GND
10.0
±0.2
4.2
±0.2
0.95
±0.15
8.2
±0.7
2.6
±0.1
3.9
±0.7
(4.3)
(4.6)
(17.9)
(2.0)
0.85
+0.2
–0.1
0.45
+0.2
–0.1
4.0
±0.2
7.9
±0.2
4.6
±0.6
16.9
±0.3
0.5
12345
P1.7
±0.7
×4=6.8
±0.7
2.8
±0.2
3.2
±0.2
φ
Pin Assignment
q IN
w SW
e GND
r ADJ
t SS
Plastic Mold Package Type
Flammability: UL 94V-0
Product Mass: Approx. 2.3 g
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