CS2082 Dual Airbag Deployment ASIC The CS2082 controls and monitors two airbag firing loops. The independent firing loops are low– and high–side controlled. Device communication is through a Serial Peripheral Interface (SPI) port, and includes frame error detection circuitry for data reliability. Diagnostics include squib resistance measurement and continuous monitoring for shorts to ground, shorts to battery, and for open loops. The high– and low–side drivers can be individually activated to guarantee function and to identify shorts between firing loops. Additional features include power on reset, overtemperature protection, a charge pump, high–side safing sensor closure detection, an analog multiplexer, a monitor to ensure battery potential, and a programmable monitor to ensure firing potential. http://onsemi.com SO–20L DW SUFFIX CASE 751D PIN CONNECTIONS AND MARKING DIAGRAM Features • Serial Input Bus • Two Squib Outputs • Low– and High–Side Control • Monitors – Squib Resistance – Short to Ground or Battery – Battery Potential – Firing Potential • Safing Sensor Detection • 60 V Peak Transient Voltage 1 A WL, L YY, Y WW, W CS2082 AWLYYWW VBAT CHRG VRES VR1 SH1 SL1 FG1 DOUT CLK MR 20 GND VCC DIN VR2 SH2 SL2 FG2 AIN AOUT CS = Assembly Location = Wafer Lot = Year = Work Week ORDERING INFORMATION Device Semiconductor Components Industries, LLC, 2001 July, 2001 – Rev. 7 1 Package Shipping CS2082EDW20 SO–20L 37 Units/Rail CS2082EDWR20 SO–20L 1000 Tape & Reel Publication Order Number: CS2082/D CS2082 CHRG VCC VRES VBAT Battery Monitor VRES Monitor Charge Pump Monitor Charge Pump Sensor Monitor CHRG VR1 1.5 Ω Gate Drive VBAT 1 VBAT Current Limit 2 10 k R SH1 + – VRES 2R + – SPI 1.5 Ω Gate Drive SL1 10 k Current Limit R Diagnostic FG1 Overtemperature GND Reset VCC CHRG VR2 1.5 Ω Gate Drive VBAT 1 VBAT Current Limit 2 + 50 mV Current Limit 10 k SH2 – + Analog MUX VRES VCC Gate Drive Resistive Measurement 1.5 Ω SL2 10 k Current Limit FG2 CS CLK DIN DOUT AIN AOUT MR Figure 1. Block Diagram http://onsemi.com 2 CS2082 MAXIMUM RATINGS* Rating Value Unit Storage Temperature –40 to 150 °C VBAT –0.3 to 24 V VRES –0.3 to 30 V VCC –0.3 to 6.0 V ESD Susceptibility (Human Body Model) 500 V Power Dissipation (Non–Firing) 0.15 W Power Dissipation (Both Firing Loops With Squibs Shorted) 140 W Power Dissipation (Squib Resistance Measurement) 1.6 W Peak Transient Voltage (46 V Load Dump @ 14 V VBAT) 60 V 230 peak °C Lead Temperature Soldering: Reflow: (SMD styles only) (Note 1) 1. 60 second maximum above 183°C. *The maximum package power dissipation must be observed. ELECTRICAL CHARACTERISTICS (4.75 V < VCC < 5.25 V, 8.0 V < VRES < 30 V, 9.0 V < VBAT < 18 V, –40°C < TA < +85°C; unless otherwise stated.) Test Conditions Parameter Min Typ Max Unit Supply Requirements VCC Quiescent Current VCC = 5.25 V – 2.0 4.0 mA VBAT Quiescent Current VBAT = 18 V – 2.5 5.0 mA VBAT Measurement Current VBAT = 18 V, RSQUIB = 1.0 Ω – – 80 mA VRES Quiescent Current VRES = 30 V – – 1.0 mA VRES Firing Current VRES = 30 V – – 3.0 mA Power on Reset VBAT = 9.0 V, VRES = 10 V Power Reset Active Voltage VCC Falling 3.50 4.00 4.25 V Power Reset Off Voltage VCC Rising 3.65 4.20 4.50 V 50 – – mV – – 1.8 V 1.2 1.6 2.0 A Hysteresis Low Side Driver – VRES = 8.0 V = VRX, VCC = 5.0 V, VBAT = 8.0 V Saturation Voltage I = 1.2 A Current Limit (ILIMIT) VSLX – VFGX = 5.0 V Turn–on Delay Time From CS falling Edge, ID = 0.9 × ILIMIT(MIN) – – 75 µs Turn–off Delay Time From CS falling Edge, ID = 0.1 × ILIMIT(MIN) – – 25 µs – – 1.8 V High Side Driver VRES = 8.0 V = VRX, VCC = 5.0 V, VBAT = 8.0 V Saturation Voltage I = 1.2 A Current Limit (ILIMIT) VRX – VSHX = 5.0 V 1.2 2.0 2.5 A VR1 Quiescent Current Drivers off VRX = VRES = 30 V – – 1.0 mA VR2 Quiescent Current Drivers off VRX = VRES = 30 V – – 100 µA Turn–on Delay Time From CS falling Edge, ID = 0.9 × ILIMIT(MIN) – – 100 µs Turn–off Delay Time From CS falling Edge, ID = 0.1 × ILIMIT(MIN) – – 25 µs Thermal Shut Down Thermal Shutdown Temp Guaranteed by Design 150 180 210 °C Thermal Hysteresis Guaranteed by Design 30 40 60 °C http://onsemi.com 3 CS2082 ELECTRICAL CHARACTERISTICS (continued) (4.75 V < VCC < 5.25 V, 8.0 V < VRES < 30 V, 9.0 V < VBAT < 18 V, –40°C < TA < +85°C; unless otherwise stated.) Parameter Test Conditions Min Typ Max Unit 7.0 – – ms 46 53 60 mV –1.0 – 1.0 % Thermal Shut Down Time to Thermal Shutdown Squib Resistive Measurements RSQUIB = 0, VRX = 30 V, T = 85°C, Guaranteed by Design VCC = 5.0 V, RMR = 49.9 , VRES = 30 V Squib Differential Voltage VDIFF = SHx – SLx, RSQUIB = 1.0 Ω to 10 Ω Difference Between SHx & MR current – SHx reference ISQUIB = 50 mA SHx Current Limit RSQUIB = 0 67 100 133 mA SLx Current Limit RMR = 0 77 115 153 mA MR Voltage Clamp – VCC – 0.3 – VCC + 0.3 V Turn On Delay Time excluding external Capacitors – – – 100 µs Turn off Delay Time – – – 50 µs 4.0 4.0 10 10 17 17 kΩ kΩ Short Measurements SHx pull–up resistance to VBAT SLx pull–down resistance VCC = 5.0 V, VRES VBAT, VRX VBAT VBAT = 18 V Pull–up resistor matching – –5.0 – 5.0 % Pull–down resistor matching – –5.0 – 5.0 % Short to VBAT Trip SHx short to Battery SLx bit set to 1 0.73 × VBAT 0.75 × VBAT 0.77 × VBAT V Short to GND Trip SHx short to GND SGx bit set to 1 0.23 × VBAT 0.25 × VBAT 0.27 × VBAT V VBAT Monitoring VCC = 5.0 V, External VBAT Diode not included, VRES = 30 V VBAT Low Trip BL bit set to 1 when below trip 7.5 8.5 9.5 V VBAT High Trip BL bit set to 0 when above trip 8.0 9.0 10 V VRES Monitoring VCC = 5.0 V, VBAT = 18 V VRES Low Trip $6d AUX register b0 = 0 15.7 17.5 19.3 V VRES High Trip $6d AUX register b0 = 0 16.5 18.5 20.5 V VRES Low Trip $6d AUX register b0 = 1 21.5 24.0 26.5 V VRES High Trip $6d AUX register b0 = 1 22.5 25 27.5 V 30 400 600 Ω 200 – 800 kHz Safing Sensor Monitor External Resistance Trip Range Charge Pump and Monitor SSC bit set when resistance is less VCC = 5.0 V, VBAT = 10 V Oscillator Frequency VRES = 10 V Charge Pump charge time CCHG = 0.1 µF, VRES = 8.0 V, Chrg from 8.0 V to 14 V – – 20 ms Charge Pump Low Voltage CL bit set to 1 when below trip 14.5 16.0 17.5 V Charge Pump High Voltage CL bit set to 0 when above trip 15.0 17.5 18.0 V Analog MUX VCC = 5.0 V AOUT Output Range – 0.1 – VCC – 0.1 V AIN Input Range – 0 – VCC V http://onsemi.com 4 CS2082 ELECTRICAL CHARACTERISTICS (continued) (4.75 V < VCC < 5.25 V, 8.0 V < VRES < 30 V, 9.0 V < VBAT < 18 V, –40°C < TA < +85°C; unless otherwise stated.) Parameter Analog MUX Test Conditions Min Typ Max Unit – – 100 mV VCC = 5.0 V MUX internal voltage drop IOUT = 100 µA Proportion of VBAT on AOUT with VBAT selected – 23 25 27 % AOUT Impedance with VBAT selected – 6.0 15.0 35 kΩ Proportion of VRES on AOUT with VRES selected – 15 17 19 % AOUT Impedance with VRES selected – 6.0 12.5 25.5 kΩ Digital Inputs – DIN, CLK, CS VCC = 5.25 V, VBAT = 18 V, VRES = 30 V Input Low Voltage (VIL) – 0 – 0.3 × VCC V Input High Voltage (VIH) – 0.7 × VCC – VCC V Input Voltage Hysteresis – 100 – – mV Input Pull Down Current (IIH) – 50 100 200 µA – – 0.4 V Digital Outputs – DOUT VCC = 4.75 V, VBAT = 18 V, VRES = 30 V Output Low Voltage (VOL) ISINK = 1.0 mA Output High Voltage (VOH) ISOURCE = 1.0 mA VCC – 0.75 – – V Tri–State Pull–up Current CS = 0, DOUT = 0 50 100 200 µA Rise | Fall Time CLOAD = 200 pF – – 50 ns PACKAGE PIN DESCRIPTION Package Lead Number SO–20L Pin Symbol 1 VBAT Battery Supply Voltage. 2 CHRG Charge pump Storage. 3 VRES Reserve Supply Voltage. 4 VR1 Loop 1 Supply. 5 SH1 Squib 1 High Side. 6 SL1 Squib 1 Low Side. 7 FG1 Loop 1 Return. 8 DOUT Serial Port output. 9 CLK Serial Port Clock. 10 MR Squib Resistance Output Current. 11 CS Serial Port Chip Select. 12 AOUT 13 AIN Analog MUX Input. 14 FG2 Loop 2 Return. 15 SL2 Squib 2 Low Side. 16 SH2 Squib 2 High Side. 17 VR2 Loop 2 Supply. Function Analog MUX Output. http://onsemi.com 5 CS2082 PACKAGE PIN DESCRIPTION (continued) Package Lead Number SO–20L Pin Symbol 18 DIN Serial Port Input. 19 VCC 5.0 V Regulated Supply. 20 GND Signal Ground. Function FUNCTIONAL DESCRIPTION the VRES and VR1 pins, the state of the internal charge pump, and the state of external VBAT and VRES power supplies. The status register is an 8–bit active–high register with bit definition as shown in Table 2. The CS2082 is an automotive air bag deployment and diagnostic system for up to two independent firing loops. Communication with the ASIC is through a synchronous serial port using Serial Peripheral Interface (SPI) protocol, at CLK rates up to 2.0 MHz. Data is simultaneously sent from the DOUT pin and received at the DIN pin under the control of the CS and CLK pins. Error detection logic is included in the SPI to guard against glitches on either the CS or CLK logic signal inputs. A valid CS frame must contain exactly 8 CLK cycles for each CS low–high–low transition. Detection of a frame error will cause input data for that frame to be ignored and an error code ($FE) to be sent during the next valid CS frame. The data at DOUT is sent MSB first and is guaranteed valid before the rising edge of CLK. The 8 bits sent from DOUT after CS goes high will be the previous data received, data from either the status register or the fault register, or the CS frame error code ($FE). The data at DIN is received MSB first and must be valid before the rising edge of CLK. The 8 bits received at DIN before CS goes low will be the current command. Table 1 defines the legal 8–bit SPI commands, where d = four data bits and x = don’t care. All other inputs will be ignored. Table 2. Status Register Bit Definition $1x $2x VALUE DESCRIPTION D7 0 Always Logic zero D6 0 Always Logic zero D5 F1 SH1 and SL1 switches active D4 F2 SH2 and SL2 switches active D3 SSC D2 RL VRES voltage is below trip D1 BL VBAT voltage is below trip D0 CL CHRG voltage is below trip Safing Sensor is closed Read Fault Register – $2x The $2x command causes the data contained in the fault register to be sent from DOUT during the next valid CS frame. The register reports fire path faults by continuously comparing each path to a portion of the voltage at the VBAT pin. The fault register is an 8–bit active–high register with bit definition as shown in Table 3. Table 1. Valid CS2082 SPI Commands COMMAND BIT FUNCTION Table 3. Fault Register Bit Definition Read Staus Register Read Fault Register $3d Squib Resistance Measurements $4d Analog MUX Select $5d Low Side Switch Control $6d Auxiliary Control Register $Ad High Side Switch Control Read Status Register – $1x The $1x command causes the data contained in the status register to be sent from DOUT during the next valid CS frame. The status register reports the condition of the firing paths, closure detection of an external safing switch between BIT VALUE D7 0 Always Logic zero D6 0 Always Logic zero D5 0 Always Logic zero D4 0 Always Logic zero D3 SB2 High Side of Sqib 2 above 75% VBAT trip threshold D2 SB1 High Side of Sqib 1 above 75% VBAT trip threshold D1 SG2 Low Side of Sqib 2 below 25% VBAT trip threshold D0 SG1 Low Side of Sqib 1 below 25% VBAT trip threshold http://onsemi.com 6 DESCRIPTION CS2082 4.5 Each SHx pin is pulled up to VBAT while each SLx pin is pulled down to GND through separate nominal 10 kΩ resistors, thus biasing each normal fire path to about 1/2 VBAT. An open fire path has been detected if both the SBx and SGx bits are set for that path. To detect faults between fire paths and to test driver function, each driver should be activated individually. The activated driver should cause its respective fault bit to be set. If an activated driver does not set its respective fault bit, a driver fault has been detected. If an activated driver causes the fault bit of an inactivated driver to be set, a fault between fire paths has been detected. Table 4 defines the implied ranges over which the various types of faults can be detected. 4.0 3.5 VMR 3.0 2.5 2.0 1.5 1.0 0.5 0 0.6 1.4 2.2 3.0 3.8 RSQUIB 4.6 5.4 Figure 2. Typical MR Voltage Response Table 4. Implied Resistive Fault Detection Ranges Fault Min Nom Max Unit Short to Ground 1 5 10 kΩ Short to Battery 1 5 10 kΩ Open 5 20 40 kΩ Driver Open 1 5 10 kΩ Driver Shorted 1 5 10 kΩ Squib to Squib 1 5 10 kΩ Measurement accuracy of the CS2082 with combined tolerances and with and external 1% load resistor at the MR pin can be defined by the equation: RSQ(E) RSQ(A)12.5%15.94% where VDIFF(IDEAL) and RMR(IDEAL) are the assumed values for the squib resistance solution algorithm, RSQ(A) is the actual squib resistance, and RSQ(E) is the result of the solution algorithm. An additional error may be added if the MR voltage is measured through the analog multiplexer. In operation, current is sourced from VBAT to the SHx pin, through the squib to the SLx pin, and returned to ground through the MR load resistor. Current clamps are provided for both the SHx and SLx pins and a voltage clamp is provided for the MR pin. These clamps along with the resolution of the ADC are the constraining factors for the minimum and maximum measurable squib resistance values. The minimum measurable squib resistance can be defined as: Squib Resistance Measurement – $3d The $3d command activates squib resistance measurement for the selected firing path. The respective active–high bit definitions are shown in Table 5. At power–up, the default path is ‘None.’ Table 5. Squib Resistance Path Select D3 D2 D1 D0 x x 0 0 NONE x x 0 1 SQUIB 1 x x 1 0 SQUIB 2 x x 1 1 NONE Path VDIFF(MIN) VDIFF(MIN) RMR(MIN) RSQUIB(MIN) ILIM(MAX) VCLAMP(MAX) Squib resistance is measured by forcing 50 mV nominal (proportional to VCC) across the squib. The resulting squib current is passed to an external load resistor at the MR pin, converting the current back into a voltage. This voltage may be read directly at the MR pin, or passed through the analog multiplexer to be read at the AOUT pin. The known values of the squib differential voltage (VDIFF) and the MR resistance (RMR), and the measured MR voltage (VMR) indicate squib resistance such that: RSQUIB VDIFF(IDEAL) RMR(IDEAL) 12% VDIFF 1% RMR 1% RSQ(A) The maximum measurable squib resistance can be defined as: RSQUIB(MAX) VDIFF(MAX) RMR(MAX) (2n 1) VCC(MIN) In the above equations, VDIFF is the SHx–SLx forced differential voltage, ILIM is the SHx resistive measure current limit, VCLAMP is the MR clamp voltage, RMR is the toleranced MR load resistor value and n is the number of bits of resolution of the ADC. It should be noted that during resistive measurements, faults to GND or BAT (dependent on VBAT voltage and RMR VDIFF VMR Typical MR voltage response for RMR = 50 Ω over a squib resistance range of 0.6 Ω to 6.0 Ω is illustrated in Figure 2. http://onsemi.com 7 CS2082 Table 7. Low Side Switch Select squib resistance) may be reported by the fault register and should be ignored. Power Dissipation during resistive measurement can be calculated as: P ISQUIB(VBAT VDIFF) (ISQUIB RMR) where VBAT is the voltage at the CS2082 VBAT pin and ISQUIB is the measurement current through the squib. A typical value for P is 300 mW when VBAT = 13.5, VDIFF = 50 mV, RSQUIB = 2.0 Ω and RMR = 49.9 Ω. The resultant increase in power dissipation will cause a corresponding increase in die temperature which will cause a corresponding decrease in time to thermal shutdown of the CS2082. To minimize the impact of squib resistive measurements on time to thermal shutdown a 5% duty cycle is recommended. D3 D2 D1 D0 x x 0 0 BOTH Active x x 0 1 SL2 x x 1 0 SL1 x x 1 1 NONE Auxiliary Control Register – $6d The $6d command selects the VRES Monitoring trip threshold. The threshold determines when the $1x Status Register reports VRES = 1. Bit assignment is shown in Table 8. At power–up, default trip is 17 V. Table 8. VRES Monitor Trip Select D3 D2 D1 D0 Trip Analog MUX – $4d x x x 0 17 V The $4d command selects one of five states at the AOUT pin. The states are: High–Z; MR voltage; AIN voltage; proportion of VBAT; proportion of VRES. The active–high Analog Mux select register bit definitions are shown in Table 6. All other states will be interpreted as High–Z. At power–up, the default state is ‘High–Z.’ x x x 1 23 V High Side Switch Control – $Ad The $Ad command activates the high side switches. When a data bit is high, that switch is turned on. More than one switch can be activated at a time. Bit assignment is shown in Table 9. Note that the $5d and $Ad commands are binary complements, i.e., by sending 1010xx11, both high side switches are activated, and by sending the complement 0101xx00, both low side switches are activated. At power–up, no switches are active. Table 6. Analog MUX Output Select D3 D2 D1 D0 State 0 0 0 0 High–Z 0 0 0 1 MR 0 0 1 0 AIN 0 1 0 0 BAT D3 D2 D1 D0 1 0 0 0 RES x x 0 0 NONE x x 0 1 SH1 x x 1 0 SH2 x x 1 1 BOTH Table 9. High Side Switch Select Low Side Switch Control – $5d The $5d command activates the low side switches. When a data bit is low that switch is turned on. More than one switch can be activated at a time. Bit assignment is shown in Table 7. At power–up, no switches are active. http://onsemi.com 8 Active CS2082 VIGN VCC VBOOST VBAT GND CHRG + CDM CCM VRES DIN VR1 VR2 SH1 SL1 CS2082 CRES CCM VCC SH2 CCM SL2 CCM FG1 FG2 DOUT AIN CLK AOUT CS MR CMR MCU Figure 3. Application Diagram http://onsemi.com 9 CDM Analog Input + CRES CS2082 PACKAGE DIMENSIONS SO–20L DW SUFFIX CASE 751D–05 ISSUE F A 20 X 45 h 1 10 20X B 0.25 DIM A A1 B C D E e H h L B M T A S B S A L H M E 0.25 10X NOTES: 1. DIMENSIONS ARE IN MILLIMETERS. 2. INTERPRET DIMENSIONS AND TOLERANCES PER ASME Y14.5M, 1994. 3. DIMENSIONS D AND E DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.15 PER SIDE. 5. DIMENSION B DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE PROTRUSION SHALL BE 0.13 TOTAL IN EXCESS OF B DIMENSION AT MAXIMUM MATERIAL CONDITION. 11 B M D 18X e A1 SEATING PLANE T C PACKAGE THERMAL DATA Parameter SO–20L Unit RΘJC Typical 17 °C/W RΘJA Typical 90 °C/W http://onsemi.com 10 MILLIMETERS MIN MAX 2.35 2.65 0.10 0.25 0.35 0.49 0.23 0.32 12.65 12.95 7.40 7.60 1.27 BSC 10.05 10.55 0.25 0.75 0.50 0.90 0 7 CS2082 Notes http://onsemi.com 11 CS2082 ON Semiconductor and are trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. 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