Multipurpose control ASIC for OMNINET – Data Sheet

AS8401

Rev. A December 1999

Page 3 of 11

Austria Mikro Systeme International AG

In applications as a high side driver the OMNIFET’s source is connected to the ASIC ground,

which switches together with the load circuit. Changes in the ASIC’s ground potential of up to

58V, and rise and fall speeds of up to 58V/µs are permitted.

Functional Descriptio n

Block diagram

Figure 1: Block diagram of the AS8401

Description

From the functional view the chip can be divided into the following units:

A driving circuit, which implements a current-controlled switching of the OMNIFET with current

pulses of approximately +30 mA, and makes the following further functions available:

• Detection of the operating condition of the OMNIFET and generation of an error status

signal (Output of a current of approximately 0.5 mA in the event of an error)

• Defined delay of the switching-on-impulse of approximately 2.0µs and implementation of a

delay of the switch-off-impulse of smaller than 0.5µs

• Defined (current-controlled) rise/fall times of approximately. 2.0µs/1,0µs

• Disconnection of the switching-on-impulse after approximately 5,0µs and connecting a cur-

rent source of approximately 3 mA whilst the OMNIFET is switched on for the supply of the

OMNIFET’s protective circuits and error recognition

• Current sinking at the OMNIFET drive pin of up to 30 mA during the off state ensures a

safe off status.