■ Overview

The AN8021L and AN8021SB are ICs which are suitable for controlling the switching power supply us ing primary side control method.

Those are most suited for a switching power supply of relatively small capacity. Less frequently used functions are removed and only the necessary minimum functions are incorporated, so that they are compact and very easy to use.

Moreover, the internal settings are incorporated as much as possible, thus cost down can be realized by decreasing the peripheral parts.

■ Features

• It operates at a control frequency up to 700 kHz, realizing the output rise time of 35 ns and the output fall time of 25 ns.

• Pre-start operating current is as small as 70 µA (typical) so that it is possible to use a miniaturized start resistor.

• Output block employs totem pole method.

  The absolute maximum rating of ±1.0 A (peak) allows the direct drive of power MOSFET.

• Built-in pulse-by-pulse overcurrent protection circuit

• Built-in protection circuit against malfunction at low voltage (on/off: 14.2 V/9.2 V)

• Equipped with timer latch function and overvoltage protection circuit.

• Two kinds of packages: 9-pin SIP, 16-pin SOP

■ Applications

• Various power supply equipment