sc4524a Semtech Corporation, sc4524a Datasheet - Page 5

• Manufacturer Part Number: sc4524a
• Description: Sc4524a 28v 2a Step-down Switching Regulator
• Manufacturer: Semtech Corporation

Pin Descriptions
SO-8

2
3
4
5
6
7
8
9
Exposed Pad
Pin Name
COMP
SS/EN
ROSC
GND
BST
SW
FB
IN
Pin Function
Emitter of the internal NPN power transistor. Connect this pin to the inductor, the freewheeling diode and the
bootstrap capacitor.
Power supply to the regulator. It is also the collector of the internal NPN power transistor. It must be closely by-
passed to the ground plane.
An external resistor from this pin to ground sets the oscillator frequency.
Ground pin
Soft-start and regulator enable pin. A capacitor from this pin to ground provides soft-start and overload hiccup
functions. Hiccup can be disabled by overcoming the internal soft-start discharging current with an external pull-
up resistor connected between the SS/EN and the IN pins. Pulling the SS/EN pin below 0.2V completely shuts off
the regulator to low current state.
The output of the internal error amplifier. The voltage at this pin controls the peak switch current. A RC compensa-
tion network at this pin stabilizes the regulator.
The inverting input of the error amplifier. If V
improve short-circuit robustness (see Applications Information for details).
Supply pin to the power transistor driver. Tie to an external diode-capacitor bootstrap circuit to generate drive
voltage higher than V
The exposed pad serves as a thermal contact to the circuit board. It is to be soldered to the ground plane of the
PC board.
IN
in order to fully enhance the internal NPN power transistor.
FB
falls below 0.8V, then the switching frequency will be reduced to
SC4524A
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