Four Channel Squib Driver IC

www.DataSheet4U.com Freescale Semiconductor Advance Information Document Number: MC33797 Rev 3.0, 11/2006 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. 33797 SQUIB DRIVER EK SUFFIX (PB-FREE) 98ARH99137A 32-PIN SOICW ORDERING INFORMATION Device MC33797EK/R2 MCZ33797EK/R2 -40°C to 85°C 32 SOICW Temperature Range (TA) Package VPWR VIN 33797 VBOOST1 TYPICAL AIR BAG POWER SUPPLY VBOOST2 FIRING CAP FIRING CAP VDIAG_1 VFIRE_1A VFIRE_1B VDIAG_2 VFIRE_2A VFIRE_2B VDD CS CLK MISO MOSI RST FEN_1 FEN_2 R_LIMIT_1 R_LIMIT_2 SENSE SQB_LO VFIRE_RTN SQB_HI /4 SQUIB (1A, 1B, 2A, 2B) /4 /4 /2 5.0 V R_DIAG MICROPROCESSOR ENABLE ENABLE 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. INTERNAL BLOCK DIAGRAM INTERNAL BLOCK DIAGRAM VFIRE_2B VDIAG_2 FEN_2 FEN_1 VDIAG_1 VFIRE_1B VFIRE_1A SQB_HI_1A SENSE_1A SQB_LO_1A VFIRE_RTN SQB_LO_1B SENSE_1B SQB_HI_1B R_LIMIT_1 R_LIMIT_2 Analog Integrated Circuit Device Data Freescale Semiconductor MOSI MISO SQB_HI_2A SENSE_2A Driver Control SQB_LO_2A VFIRE_RTN SQB_LO_2B Driver Control Control and Diagnostic Multiplex SENSE_2B SQB_HI_2B RST R_DIAG GND Figure 3. 33797 Simplified Internal Block Diagram 33797 2 Driver Control Driver Control VFIRE_2A VDD CLK CS PIN CONNECTIONS PIN CONNECTIONS SQB_LO_1A SENSE_1A MOSI CLK SQB_HI_1A VFIRE_1A VDIAG_1 GND MISO VDD VFIRE_1B SQB_HI_1B FEN_1 R_LIMIT_1 SENSE_1B SQB_LO_1B 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 SQB_LO_2A SENSE_2A CS RST SQB_HI_2A VFIRE_2A VDIAG_2 VFIRE_RTN VFIRE_RTN R_DIAG VFIRE_2B SQB_HI_2B FEN_2 R_LIMIT_2 SENSE_2B SQB_LO_2B Figure 4. Pin Function Description Table 1. Pin Function Description Pin 1 Pin Name SQB_LO_1A Pin Function Output Formal Name Squib Lo 1A Pin Description Drain of the low-side switch that connects to the low pin of Squib_1A Used during standard applications involving a four-channel squib driver IC or during cross-coupling applications involving two four-channel squib driver ICs (squib driver IC #1 and squib driver IC #2). Serial data input for SPI interface. Serial clock input for SPI interface. Drain of the high-side switch that connects to the low pin of Squib_1A Firing supply pin for Squib_1A. 2 SENSE_1A Input Squib Sense 1A 3 4 5 MOSI CLK SQB_HI_1A Input Input Output Data Input 1 Serial Clock Squib Hi 1A 6 VFIRE_1A Supply Squib Firing Supply 1A Squib Diagnostic 1A and 1A Device Ground Data Output 0 Logic Power Squib Firing Supply 1B Squib Hi 1B 7 VDIAG_1 Input Diagnostic pin for high-side safing sensor for squibs 1A and 1B and the VFIRE supply voltage. Device ground pin for internal logic and diagnostic circuitry. Serial data output for SPI interface. Device power pin for internal logic and diagnostic circuitry. Firing supply pin for Squib_1B. 8 9 10 11 GND MISO VDD VFIRE_1B Ground Output Input Supply 12 SQB_HI_1B Output Drain of the high-side switch that connects to the low pin of Squib_1B Active high input signal to enable operation of the squib_1A and Squib_1BFET drivers. External resistor to ground is used to set current limit for Squib_1A and squib_1B FET drivers. 13 FEN_1 Input FET Driver 1A and 1B Limit Resistor - 1A and 1B 14 R_LIMIT_1 Output 33797 Analog Integrated Circuit Device Data Freescale Semiconductor 3 PIN CONNECTIONS Table 1. Pin Function Description (continued) Pin 15 Pin Name SENSE_1B Pin Function Input Formal Name Squib Sense 1B Pin Description Used during standard applications involving a four-channel squib driver IC and during cross-coupling applications involving two four-channel squib driver ICs (squib driver IC #1 and squib driver IC #2). Drain of the low-side switch that connects to the low pin of Squib_1B Drain of the low-side switch that connects to the low pin of Squib_2B Used during standard applications involving a four-channel squib driver IC and during cross-coupling applications involving two four-channel squib driver ICs (squib driver IC #1 and squib driver IC #2). External resistor to ground is used to set current limit for Squib_2A and squib_2B FET drivers. Active high input signal to enable operation of the squib_2A and Squib_2B FET drivers. Drain of the high-side switch that connects to the low pin of Squib_2B. Firing supply pin for squib_2B. 16 SQB_LO_1B Output Squib Lo 1B 17 SQB_LO_2B Output Squib Lo 2B 18 SENSE_2B Input Squib Sense 2B 19 R_LIMIT_2 Output Limit Resistor - 2A and 2B FET Driver 2A and 2B Squib Hi 2B 20 FEN_2 Input 21 SQB_HI_2B Output 22 VFIRE_2B Supply Squib Firing Supply 2B Limit Resistor Diagnostic Squib Fire Power Ground Squib Fire Power Ground Squib Diagnostic 2A and 2b Squib Firing Supply 2A Squib Hi 2A 23 R_DIAG Input External resistor to ground is used to set the diagnostic current for squib resistance. Power Ground for squibs 1A, 1B, 2A, and 2B 24 VFIRE_RTN Ground 25 VFIRE_RTN Ground Power Ground for squibs 1A, 1B, 2A, and 2B 26 VDIAG_2 Supply Diagnostic pin for high-side safing sensor for squibs 2A and 2B and the VFIRE supply voltage. Firing supply pin for squib_ 2A 27 VFIRE_2A Supply 28 SQB_HI_2A Output Drain of the high-side switch that connects to the low pin of Squib_2A Reset, Active Low Chip Select for SPI interface, Active Low Used during standard applications involving a four-channel squib driver IC or during cross-coupling applications involving two four-channel squib driver ICs (squib driver IC #1 and squib driver IC #2). Drain of the low-side switch that connects to the low pin of Squib_2A 29 30 31 RST CS SENSE_2A Input Input Input Reset Chip Select Squib Sense 2A 32 SQB_LO_2A Output Squib Lo 2A 33797 4 Analog Integrated Circuit Device Data Freescale Semiconductor ELECTRICAL CHARACTERISTICS MAXIMUM RATINGS ELECTRICAL CHARACTERISTICS MAXIMUM RATINGS Table 2. Maximum Ratings All voltages are with respect to ground unless otherwise noted. Exceeding these ratings may cause a malfunction or permanent damage to the device. Rating INPUT ELECTRICAL RATINGS Voltage on VDD Voltage on Input pins CS, CLK, D1, D0, FEN_1, FEN_2, RESETB, R_DIAG, R_LIMIT_X Voltage on Squib pins SQB_HI_XX, SQB_LO_XX, SENSE_XX Voltage on pins VDIAG_X, VFIRE_XX ESD Voltage Human Body Model Machine Model Maximum VVFIRE with Pulsed Output RSQUIB = 2.0 Ω, tON = 0.8 ms, ISQUIB = 2.24 A RSQUIB = 1.2 Ω, tON = 0.8 ms, ISQUIB = 2.24 A RSQUIB = 0.1 Ω, tON = 0.60 ms, ISQUIB = 2.24 A THERMAL RATINGS Storage Temperature Junction Temperature Ambient Continuous (Prior to Squib Deployment) t ≤ 5.0 ms (Post-Squib Deployment) Peak Package Reflow Temperature During Reflow (4), (5) Thermal Resistance (Junction-to-Ambient) TSTG TA TJCONT TJDPYD TPPRT RθJ-A 155 85 100 300 Note 5. 74 °C °C/W °C °C (2), (3) (1) Symbol Value Unit VDD VI 7.0 -0.3 to VDD + 0.3 V V VVFIRE_XX VDIAG_X -0.3 to VVFIRE + 0.3 -0.3 to 35 V V V VESD1 VESD2 VFPULSE ±2000 ±200 V 35 25 25 Notes 1 ESD1 testing is performed in accordance with the Human Body Model (CZAP = 100 pF, RZAP = 1500 Ω), ESD2 testing is performed in accordance with the Machine Model (CZAP = 200 pF, RZAP = 0 Ω). 2 With a nominal squib load, the FET squib driver will not enter thermal shutdown until the driver has been active for a minimum of 2.1 ms. The individual squib driver thermal shutdown will not affect other squib driver firing “ON” times. With a shorted squib load, the FET squib driver will not enter thermal shutdown until the driver has been active for a minimum of 2.1 ms. When the thermal shutdown limit is exceeded, the FET driver will turn OFF and the thermal status bit will be set to 1. The FET squib driver can be activated through the arm / fire command when the TEMPRENABLE (MIN) is reached (thermal shutdown status “0”). Nominal squib load is 2.15 Ω ± 0.15 Ω. Shorted squib load is 0.1 Ω. Three-squib driver with RSQUIB = 0.1 Ω conditions. Remaining squib driver conditions: RSQUIB = 1.2 Ω, tON = 4.0 ms, ISQUIB = 2.0 A, VVDIAG_X = VVFIRE_XX = 35 V. Pin soldering temperature limit is for 10 seconds maximum duration. Not designed for immersion soldering. Exceeding these limits may cause malfunction or permanent damage to the device. Freescale’s Package Reflow capability meets Pb-free requirements for JEDEC standard J-STD-020C. For Peak Package Reflow Temperature and Moisture Sensitivity Levels (MSL), Go to www.freescale.com, search by part number [e.g. remove prefixes/suffixes and enter the core I