FEATURES

10- to 450-V Input Range

Current-Mode Control

125-mA Output Drive

Internal Start-Up Circuit

Internal Oscillator (1 MHz)

SHUTDOWN and RESET

DESCRIPTION

The Si9120 is a BiC/DMOS integrated circuit designed for use

in low-power, high-efficiency off-line power supplies.

High-voltage DMOS inputs allow the controller to work over a

wide range of input voltages (10- to 450-VDC). Current-mode

PWM control circuitry is implemented in CMOS to reduce

quiescent current to less than 1.5 mA.

A CMOS output driver provides high-speed switching for

MOSFET devices with gate charge, Qg, up to 25 nC, enough

to supply 30 W of output power at 100 kHz. These devices,

when combined with an output MOSFET and transformer, can

be used to implement single-ended power converter

topologies (i.e., flyback and forward).

The Si9120 is available in both standard and lead (Pb)-free

16-pin plastic DIP and SOIC packages which are specified to

operate over the industrial temperature range of −40 C to

85 C.