52
ICs
1-1-3 DC/DC Converter ICs
■Lineup
Part Number SI-8008HFE SI-8050HFE
VO (V) Variable (0.8 to 15) 5
IO (A) 5.5
■Absolute Maximum Ratings
Unit
V
W
°C
°C
°C/W
°C/W
Ratings
43
25 (with infinite heatsink)
20 (with infinite heatsink)
2.15 (without heat sink, standalone operation)
1.72 (without heatsink, standalone operation)
+150
–40 to +150
5
58
Symbol
VIN
PD1-1
PD1-2
PD2-1
PD2-2
Tj
Tstg
θ
j-c
θ
j-a
Parameter
DC Input Voltage
Power Dissipation
Junction Temperature*
Storage Temperature
Thermal Resistance (Junction to Case)
Thermal Resistance (Junction to Ambient Air)
■Recommended Operating Conditions
■Features
• Compact full-mold package (equivalent to
TO220)
• Output current: 5.5 A
• High efficiency: 83% typ. (at Vo = 5 V)
• Requires only 4 discrete components
• Built-in reference oscillator (150 kHz)
• Built-in drooping-type-overcurrent and
thermal protection circuits
• Built-in soft start circuit (Output ON/OFF
available)
(Ta=25°C)
Full-Mold, Separate Excitation Step-down Switching Mode
SI-8000HFE Series
■Applications
• Onboard local power supplies
•OA equipment
Conditions
Limited by thermal protection, Tjmax=150°C
Tjmax=125°C
Limited by thermal protection, Tjmax=150°C
Tjmax=125°C
*: This product has built-in thermal protection circuits that may operate when the junction temperature rises above 130°C.
The recommended design for the junction temperature during operation is below 125°C.
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-8008HFE SI-8050HFE
Vo+3
*1
to 40 8 to 40
0.8 to 24 5.0
0 to 5.5
–30 to +125
–30 to +85
*1: The minimum value of an input voltage range is the higher of 4.5 V or V
O
+ 3 V.
■Electrical Characteristics
SI-8008HFE (at Vo = 5 V) SI-8050HFE
min.
0.784
5.6 5.6
typ.
0.800
V
IN
=15V, I
o
=1A
max.
0.816
50
min.
4.90
typ.
5.00
V
IN
=15V, I
o
=1A
±0.5
V
IN
=15V, I
o
=1A, T
c
=0 to 100°C
83
V
IN
=15V, I
o
=3A
max.
5.10
Vo
V
ADJ
∆V
OLOAD
±0.1
V
IN
=15V, I
o
=1A, T
c
=0 to 100°C
83
V
IN
=15V, I
o
=3A
∆Vo/∆T
∆V
ADJ
/∆T
η
10
V
SSL
=0V
10
V
SSL
=0V
0.5
30
0.5
30
20
V
IN
=15V, I
o
=0.2 to 5.5A
20
V
IN
=15V, I
o
=0.2 to 5.5A
150
V
IN
=15V, I
o
=3A
150
V
IN
=15V, I
o
=3A
fo
60
V
IN
=10 to 30V, I
o
=3A
80 60
V
IN
=10 to 30V, I
o
=3A
80
50
∆V
OLINE
6
V
IN
=15V, I
o
=0A
6
V
IN
=15V, I
o
=0A
V
IN
=15V V
IN
=15V
I
q
200
V
IN
=15V, V
SS
=0V
200
V
IN
=15V, V
SS
=0V
400 400
I
q(OFF)
Low Level Voltage
Outflow Current at
Low Voltage
V
SSL
I
SSL
I
S
V
mV/°C
%
kHz
mV
mV
A
V
µA
mA
µA
Parameter
Conditions
Conditions
Conditions
Conditions
Conditions
Conditions
Conditions
Conditions
Conditions
Conditions
Symbol Unit
Ratings Ratings
Output Voltage
Reference Voltage
Efficiency
Oscillation Frequency
Line Regulation
Quiescent Circuit Current
Load Regulation
Overcurrent Protection
Starting Current
ON/OFF Pin*
Temperature Coefficient of Output Voltage
Te mperature Coefficient of Reference Voltage
(Ta=25°C)
*: 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 cur-
rent securely to protect the transistor if C3 capacitance is large. The SS pin is pulled up to the
power supply in the IC, so applying the external voltage is prohibited. If the pin is not used,
leave it open.
SI-8000HFE SI-8000HFE
SS5SS5SS
C3C3
5
V
OUT. ON/OFF
Soft start
Soft start
+V
OUT. ON/OFF
SI-8000HFE
