33797 Datasheet, PDF (1/34 Pages) Freescale Semiconductor, Inc – Four Channel Squib Driver IC

Freescale Semiconductor
Advance Information
Four Channel Squib Driver IC
The Four Channel Squib Driver IC is a complete squib diagnostic
and deployment interface for use in automotive air bag modules.
Extensive diagnostics and system control features are incorporated
to provide fail-safe operation. The device contains a serial peripheral
interface (SPI) compatible 8-bit interface to allow microprocessor
control.
The device has the capability to be used in a standard four-channel
squib driver IC or in a cross-coupled state with the high- and low-side
squib drivers located on separate squib driver ICs. Both the high- and
low-side output drivers are protected against temporary shorts to
battery or ground. The current limit threshold is set by an external
resistor.
Features
• Four-Channel High-Side and Low-Side 2.0 A FET Switches
• Externally Adjustable FET Current Limiting
• Adjustable Current Limit Range: 0.8 A to 2.0 A
• Individual Channel Current Limit Detection with Timing Duration
Measurement, Communicated via SPI
• 8-Bit SPI for Diagnostics and FET Switch Activation
• Diagnostics for High-Side Safing Sensor Status
• Resistance and Voltage Diagnostics for Squibs
• Squib Driver IC Capability to Be Used for Cross-Coupled Driver
Firing Application (Allows High- and Low-Side FET Switches to Be
Located on Separate Squib Driver ICs)
• Pb-Free Packaging designated by Suffix Code EK
Figure 1.
Document Number: MC33797
Rev 3.0, 11/2006
33797
SQUIB DRIVER
EK SUFFIX (PB-FREE)
98ARH99137A
32-PIN SOICW
ORDERING INFORMATION
Device
MC33797EK/R2
MCZ33797EK/R2
Temperature
Range (T_A)
-40°C to 85°C
Package
32 SOICW
33797
V_PWR
VIN
VBOOST1
VDIAG_1
TYPICAL
AIR BAG
FIRING
VFIRE_1A
POWER SUPPLY
CAP
VFIRE_1B
/4
SQB_HI
SENSE ^/4
SQUIB
(1A, 1B, 2A, 2B)
VBOOST2
VDIAG_2
SQB_LO ^/4
5.0 V
FIRING
CAP
VFIRE_2A
VFIRE_2B
/2
VFIRE_RTN
MICROPROCESSOR
ENABLE
ENABLE
VDD
CS
CLK
MISO
MOSI
RST
FEN_1
FEN_2
R_LIMIT_1
R_LIMIT_2
R_DIAG
GND
Figure 2. 33797 Simplified Application Diagram
* This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
© Freescale Semiconductor, Inc., 2006. All rights reserved.