Document Number: MC33789 Freescale Semiconductor Rev. 4.0, 9/2014 Advance Information Airbag System Basis Chip (SBC) with 33789 Power Supply and PSI5 Sensor Interface AUTO RESTRAINT The 33789, a SafeAssure SMARTMOS solution, is a mixed signal IC for airbag safety applications. The 33789 provides a cost effective and flexible system IC solution across the range of airbag partitions used in cars and other vehicles. The 33789 connects to the 12 V vehicle battery and supplies the multiple voltages of a typical airbag system. The 33789 can detect switched input states, communicate with both local and remote crash sensors. It offers an industry standard interface (SPI) and four PSI5 master interfaces. The 33789 has a AE SUFFIX (PB-FREE) dedicated safing state machine that complements the airbags MCU hardware/ EXPOSED PAD software safing approach. Also included are a diagnostic - self protection 98ASA10763D capability and a programmable analog interface accessible by the system MCU. 64-PIN LQFP The 33789 is well suited for use in low to high end airbag systems by allowing the designer to scale a design for the number of firing loops needed while providing enhanced safety and system reliability. Applications Features Airbag safety Designed to operate 5.2 V V 20 V, up to a 40 V transient PWR Safing state machine with programmable sensing thresholds Two configurable high-side/low-side drivers with PWM capability Four PSI5 satellite sensor master interfaces Self-protected and diagnostic capability Watchdog and system Power ON Reset (POR) Supports complete airbag system power supply architecture, including system power mode control, supplies for squib firing (33 V), satellite sensors (6.3 V), and local ECU sensors and ECU logic circuits (5.0 V) Nine configurable switch input monitors for simple switch and Hall- effect sensor interfaces with internal power supply 16-bit SPI interface LIN 2.1 physical layer interface 33789 Wake Up V BAT IN1 WAKE IN2 V VPWR BAT 9 Input Monitors IN8 BSTSW IN9 33 V LIN VBST PSI5 1 VER 4 Satellite PSI5 2 Sensor Energy 5.0 V Interfaces ERSW Storage PSI5 3 5.0 V PSI5 4 VFIRE x SQB H1 V PWR OUT1 D SQB H1 BUCKSW OUT1 S 9.0 V VBUCK 5.0 V Squib 5.0 V VCCDRI Output Squib Driver 1 X/Y Axis Sensor SPI Driver 2 SPI Accel. VCC Sensor SQB L1 5.0 V SQB L1 SPI A AIN AOUT VDD Cross-coupled ARM FEN 1 Squib RESET FEN 2 Connections RESET RESET Squib Driver SPI SPI B SPI 2 ARM X and ARM Y for Squib Driver 2 FENs MCU Figure 1. 33789 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., 2010-2014. All rights reserved.ORDERABLE PARTS ORDERABLE PARTS This section describes the part numbers available to be purchased along with their differences. Valid orderable part numbers are provided on the web. To determine the orderable part numbers for this device, go to