DESCRIPTION

· The L9634 is an Octal Intelligent Squib Driver ASIC designed using ST's proprietary BCD4 technology.

· It is packaged in a 44-pin Thin Quad Flat Pack (TQFP) and is intended to deploy up to eight airbag squib circuits.

· The device provides diagnostics for each of the deployment drivers, with each driver capable of delivering up to 1.75A minimum for up to 4ms.

· Deployment current and time are programmable via the SPI port.

FEATURES

· Eight squib deployment drivers with programmable deployment current and time via SPI (1.2A/2ms and 1.75A/4ms).

· Capability to deploy with 1.47A (2.14A) under 40V (21V) load-dump condition and the low side MOS shorted to -1V.

· 5.5MHz SPI interface with message validation.

· Four channels of discrete/serial logic arming interface programmable via SPI.

· Deployment driver self-diagnostics including short to battery/ground, open circuit, squib resistance measurement, short between channels detection, high and low side MOS tests, and ground loss detection.

· Operating ambient temperature range from -40°C to +85°C.

· 4KV ESD capability on all output-driver pins and 2KV on all others.

APPLICATIONS

· The L9634 is primarily used in automotive safety systems, specifically for airbag deployment circuits.