SI-8000SD Series
■External Dimensions (TO263-5)
(Unit : mm)
Case temperature
measurement point
10.0±0.2
(8.0)
Pin Assignment
(4.4)
q
w
e
r
t
VIN
(15°)
4.5±0.2
+0.10
–0.05
1.3
SWOUT
GND
VOS
3-R0.3
(2×R0.45)
(3°)
φ
1.5 Dp:±0.2
S.S
0.10±0.15
(3°)
(3°)
Plastic Mold Package Type
Flammability: 94V-0
2.4±0.2
(R0.3)
Product Mass: Approx. 1.48g
0.88±0.10
(R0.3)
0 to 6°
(0.5)
0.8±0.1
(1.7±0.25
)
0.8±0.1
(1.7±0.25
)
(1.7±0.25
)
(1.7±0.25
)
1
2
3
4
5
9.9±0.2
(3°)
(3°)
2-R0.3
10.0±0.02
■Block Diagram
■Reference Data
Copper Laminate Area on Glass Epoxy Board vs.
thermal resistance (junction to ambient air) (Typical Value)
1
VIN
SWOUT
2
Internal power
supply
Overcurrent
protection
55
50
Oscillator
Reset
With glass epoxy board of 40 × 40 mm
Latch & driver
45
Thermal
protection
Comparator
40
θ
VOS
4
35
Error
amplifier
30
0
200
400
600
800
1000 1200 1400 1600 1800
Reference voltage
Copper Laminate Area (mm2)
S.S
GND
5
3
■Typical Connection Diagram
L1
1
2
4
C1 : 50V/1000µF
C2 : 50V/1000µF
C3 : 0.01µF
V
OUT
SWOUT
OS
V
IN
VIN
V
SI-8000SD
(only when soft start function is used)
L1 : 150µH
D1 : SPB-G56 (Sanken)
+
+
S.S
GND
3
C
1
C2
D1
5
C
3
GND
GND
Diode D1
• Be sure to use Schottky-barrier diode as D1.
If other diodes like fast recovery diodes are used, ICs may be destroyed because of the reverse voltage generated by the recovery voltage or ON
voltage.
Choke coil L1
• If the winding resistance of the choke coil is too high, the efficiency may drop below the rated value.
• As the overcurrent protection starting current is about 3.5 A, take care concerning heat radiation from the choke coil caused by magnetic saturation
due to overload or short-circuited load.
Capacitors C1, C2, and C3
• As large ripple currents flow through C1 and C2, use high-frequency and low-impedance capacitors aiming for switching-mode-power-supply use.
Especially when the impedance of C2 is high, the switching waveform may become abnormal at low temperatures.
For C2, do not use a capacitor with an extremely low equivalent series resistance (ESR) such as an OS capacitor or a tantalum capacitor, which may
cause an abnormal oscillation.
• C3 is a capacitor for soft start. Leave pin 5 open if the soft start function is not used.
This pin is pulled up with a pull-up resistor inside the ICs.
To create the optimum operating conditions, place the components as close as possible to each other.
ICs
21
ETC [ ETC ]
