50 ICs
1-1-3 DC/DC Converter ICs
Parameter
Reference V oltage
Temperature Coefficient of Reference Voltage
Efficiency
Oscillation Frequency
Line Regulation
Load Regulation
Overcurrent Protection Starting Current
Low Level V oltage
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 V oltage
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
51
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