[ASTEC Semiconductor]

Description

The AS23xx is a housekeeping circuit for monitoring the outputs of power supplies. It directly senses all the output rails without the need for external dividers and detects undervoltage and overvoltage. It also provides an additional undervoltage comparator which may be configured with any arbitrary hysteresis to sense a divided down representation of the AC bulk voltage. The housekeeping section provides all the features necessary to allow external caps to set the common timing features of PC type power supplies. In addition, negative rails may be sensed without the necessity of a VEE connection, and negative sensing may be disabled without affecting operation of the positive sense section. The 2.5 V series reference is available and can source up to 5 mA. This IC is available in 16 lead packages. Outputs include a POK (Power OK) and a fault signal.

The AS2333 includes sensing for ±12 V, 5 V, and 3.3V. The AS2350 exchanges a -5 V sense capability for the 3.3 V input. The AS2316 monitors all supply voltages, but lacks CBD (Crow-Bar Driver).

Features

• Standard PC Power Good:

UV Detection on 4 rails

UV Detection of AC/Bulk supply

OV Detection on 4 rails

Open collector PG out

• Pogrammable Fault output:

OV

OV plus UV

OV plus UV after startup delay

• OV Crow Bar Driver

• Digital ON/OFF input

• 2.5V Voltage Reference

• Operates from 5V or 12V rail