Analog, Mixed Signal and Power ManagementEyEyeebbrrooww HHeeadlinadlinee MC33789 Airbag system basis chip (SBC) with power supply and PSI5 sensor interface Target Applications Automotive Airbag Safety Systems Overview Basic Airbag Systems The MC33789 is a mixed signal IC for airbag safety applications. The MC33789 is a SafeAssure functional safety solution. The MC33789 provides a cost effective and flexible Advanced Airbag Systems system IC solution across the range of airbag partitions used in cars and other vehicles. Motorcycle - ATV Safety Systems Frame Mounted Single Loop The MC33789 connects to the 12 V vehicle battery and supplies the multiple voltages of a Airbag System typical airbag system. The MC33789 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 MC33789 has a dedicated safing state machine that complements the airbags MCU hardware/software safing approach. Also included are a diagnostic - self protection capability and a programmable analog interface accessible by the system MCU. MC33789 Simplified Application Drawing MC33789 Wake Up VBAT IN1 WAKE VBAT IN2 VPWR 9 Input Monitors IN8 BSTSW IN9 33V VBST PSI5 1 PSI5 2 VER 5V 4 Satellite PSI5 3 Energy Sensor 5V Reserve Interfaces PSI5 4 VFIRE x ERSW SQB H1 VBAT BUCKSW SQB H1 OUT1 D 9V VBUCK OUT1 S Squib 5V 5V Driver 1 Squib VCCDRI Output Driver 2 Sensor SPI X/Y-axis SPI VCC Accel. Sensor SQB L1 5V AOUT LIN SQB L1 FEN 1 RESET SPI A ARM FEN 2 AIN RESET RESET Cross-coupled Squib Driver SPI Squib SPI B SPI Connection ARM X and ARM Y for Squib Driver 2 FENs 2 MCUSafeAssure Protection, Performance, and Ordering Information The MC33789, a SafeAssure solution, is Performance well suited for use in low to high end airbag Performance Typical Values safety systems by allowing the designer to scale a design for the number of firinig Operating Voltage 5.2 V < V < 20 V PWR loops needed while providing enhanced Energy Reserve and Squib Firing safety and system reliability. 33 V Supply VCC Supply 5.0 V SafeAssure Program: Selectable Switch Input Detector Functional Safety, Simplified 1.5 V, 2.5 V, 5.0 V, 6.5 V Supplies Freescales SafeAssure functional safety Configurable Driver program is designed to help system Output Voltage 0 V / V PWR manufacturers more easily achieve system Output Current Min 70 mA compliance with functional safety standards: PWM Frequency 128 Hz International Standards Organization (ISO) Analog Output Voltage 0 V < V < V AOUT CC 26262 and International Electrotechnical ESD (HBM) 2000 V Commission (IEC) 61508. The program highlights Freescale solutions hardware Ambient Operating Temperature (T ) -40 C to +125 C A and software that are optimally designed Junction Temperature (T ) -40 C to +150 C J to support functional safety implementations Protection and come with a rich set of enablement Protection Detect Limiting Shut Down Auto Retry Status Report collateral. For more information, visit freescale.com/safeassure. Over-voltage Over-current/SC MC33789 Key Features Over-temperature Designed to operate 5.2 V < V < 20 PWR Open load V, up to 40 V transients Ordering Information Safing state machine with Order Number Temperature Range Package programmable sensing thresholds MCZ33789AE/R2 - 40 C to 125 C 64 LQFP-EP Two configurable high side/low side Contact Sales Evaluation board to demonstrate the key features of the MC33789 drivers with PWM capability Data Sheet - Airbag System Basis Chip (SBC) w/ Power Supply and PSI5 MC33789 Sensor Four PSI5 satellite sensor master SG1002 Selectable Switch Input Detector Suppliesr interfaces SG187 Automotive Selector Guide Self-protected and diagnostic capability Questions System power mode control with watchdog and system Power ON Reset Question Why are there no squib system supplier who addressed the (POR) drivers integrated need for low cost vs. flexibility. Supports complete airbag system Answer The number of squib Question Is the MC33789s PSI5 power supply architecture, including drivers varies across vehicle Interface interoperable with other platforms so a fixed number could supplies for squib firing (33 V), satellite PSI5 products be too many or not enough for an sensors (6.3 V), and local ECU Answer Yes, Freescale is part of application. sensors and logic circuits (5.0 V) the PSI5 consortium and has an Question What drove the MC33789 ecosystem of crash sensor parts that Nine configurable switch input monitors final silicon partition communicate with the MC33789. The for simple switch and Hall-effect sensor MC33789s PSI5 master interface interfaces with internal power supply Answer The MC33789 was the supports the P10P 500/3L operation result of collaboration between 16-bit SPI interface mode specified in the PSI5 standard Freescale and a leading airbag V1.3. LIN 2.1 physical layer interface. For more information, please visit freescale.com Freescale and the Freescale logo are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. Qorivva, SafeAssure and Xtrinsic are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. The Power Architecture and Power.org word marks and the Power and Power.org logos and related marks are trademarks and service marks licensed by Power.org. 2012 Freescale Semiconductor, Inc. Document Number: MC33789FS, Rev. 3.0