1-1-3 DC/DC Converter ICs
SI-8000HD Series Surface-Mount, Separate Excitation Step-down Switching Mode
■Features
■Absolute Maximum Ratings
• Surface-mount package (TO263-5)
Parameter
Symbol
Ratings
Unit
V
Conditions
Input Voltage
VIN
43
• Output current: 5.5 A
Power Dissipation*1
PD
3
+150
W
When mounted on glass-epoxy board measuring 40
×
40 mm (copper laminate area: 100%
)
• High efficiency: 83% (at TYP, Vo = 5 V)
Junction Temperature*2
Tj
°C
• Requires only 5 discrete components (SI-
8008HD)
Storage Temperature
Tstg
θj-c
–40 to +150
3
°C
Thermal Resistance (Junction to Case)
Thermal Resistance (Junction to Ambient Air)
°C/W
°C/W
When mounted on glass-epoxy board measuring 40
When mounted on glass-epoxy board measuring 40
×
40 mm (copper laminate area: 100%
40 mm (copper laminate area: 100%
)
)
• Built-in reference oscillator (150 kHz)
θj-a
33.3
×
• Built-in drooping-type overcurrent and thermal
protection circuits
*1: Limited by thermal protection circuit
*2: 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.
• Built-in soft start circuit (Output ON/OFF
available)
• Low current consumption during off
■Applications
• DVD recorder, FPD-TV
• Onboard local power supplies
• OA equipment
■Recommended Operating Conditions
Ratings
SI-8008HD
Vo+3*1 to 40
0.8 to 24
Unit
Conditions
Parameter
Symbol
Input Voltage Range
VIN
VO
IO
V
V
Output Voltage Range
Output Current Range
0 to 5.5
A
VIN ≥ Vo+3V
Operating Junction Temperature Range
Operating Temperature Range
Tjop
Top
–30 to +100
–30 to +85
°C
°C
*1: The minimum value of the input voltage range is 4.5 V or Vo+3 V, whichever is higher.
■Electrical Characteristics
(R1=4.2kΩ, R2=0.8kΩ when Ta=25°C and Vo=5V)
Ratings
Paramter
Symbol
VADJ
SI-8008HD
Unit
min.
typ.
max.
0.784
0.800
0.816
V
Reference Voltage
Conditions
(∆VADJ/∆T)
Conditions
VIN=15V, Io=1A
±0.1
mV/°C
%
Temperature Coefficient of Reference Voltage
Efficiency
VIN=15V, Io=1A, Tc=0 to 100°C
η
83
Conditions
Conditions
VIN=15V, Io=3A
fo
150
kHz
Oscillation Frequency
Line Regulation
VIN=15V, Io=3A
∆VOLINE
60
80
mV
Conditions
VIN=10 to 30V, Io=3A
∆VOLOAD
20
VIN=15V, Io=0.2 to 5.5A
6.5
50
mV
Load Regulation
Conditions
IS
5.6
7.5
A
Overcurrent Protection Starting Current
Low Level Voltage
SS Pin*1
Conditions
VIN=15V
VSSL
ISSL
0.5
30
V
10
VSSL=0V
6
µA
Outflow Current at Low Voltage
Conditions
Conditions
Iq
mA
VIN=15V, Io=0A
200
Quiescent Circuit Current
Iq(OFF)
400
µA
Conditions
VIN=15V, VSS=0V
*1: 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-8008HD
SI-8008HD
SI-8008HD
5
SS
5
SS
C3
5 SS
C3
VO.ON/OFF
Soft start
Soft start
+Vo. On/OFF
ICs
30
ETC [ ETC ]
