MAXIM MAX13036 handbook
Contents
1. INTERFACE SHIFT REGISTER INTERRUPT LOGIC VL VL is the power supply input for the digital input output buffers The SPI interface CS CLK SDI SDO and digital outputs DOO DO1 are referenced to the volt age on VL Connect VL to the system s 2 7V to 5 5V logic level supply Bypass VL to ground with a 0 1uF capacitor placed as close as possible to the device BAT BAT is the main power supply input Bypass BAT to ground with a 0 1uF ceramic capacitor placed as close as possible to BAT In addition bypass BAT with a 10pF or greater capacitor BAT can withstand DC volt ages up to 42V Mechanical Switch Inputs INO IN7 INO through IN7 are the inputs for remote mechanical Switches The status of each switch input is indicated by the SWO through SW7 bits in the status register and each switch input can be programmed to not assert an interrupt INT by writing to the PO through P7 bits in the command register All switch inputs are configured to assert an interrupt upon power up 9 0 LXVIN MAX13036 Automotive Contact Monitor and Level Shifter The first four inputs INO IN3 are intended for ground connected switches The remaining four inputs INA IN7 can be programmed in sets of two for either ground con nected or battery connected switches by writing to the MO and M1 bits see Table 5 The default state after power up is IN2 IN7 configured for ground connected switches and INO IN12. Automotive Contact Monitor and Level Shifter Functional Diagram MAXIM MAX13036 BATREF WETTING CURRENT CONTROL LEVEL TRANSLATORS NY CO X Co SB HYST Detailed Description The MAX13036 automotive contact monitor and level shifter monitors and debounces eight remote mechanical switches and asserts an interrupt INT if a switch changes state Any of the switch inputs can be prohibited from asserting an interrupt The switch threshold levels are set to 50 of the voltage applied to BATREF All switch inputs feature a common adjustable hysteresis debounce time and wetting current Two switch inputs INO IN1 are programmable to have direct outputs DOO DO1 useable for PWM or other timing based signals The MAX13036 features an SPI interface to monitor individual switch inputs and to configure interrupt masking hysteresis and wetting current enable disable switch configuration battery connected or ground con nected and scanning period The MAX13036 features three modes of operation nor mal mode scan mode and shutdown mode In normal mode the part is fully functional and sensing resistors are connected to all switch inputs In scan mode the sensing resistors are connected for a finite duration to reduce power consumption In shutdown mode all switch inputs are high impedance to further reduce power consumption DIGITAL INTERFACE SPI
3. Rising Edge of CLK to SDO Data Valid tSO DIS L 3 0V to 5 5V Figures 1 and 2 SDO 15pF L 3 0V to 5 5V Figure 1 CTDEB 500pF 10nF Note 6 tVALID Debounce time tDEB Scanning Time Pulse tSCAN Scanning Time Period tscaN P SC2 0 SC1 1 5 0 1 Wetting Time Pulse tWET WTOFF 0 Time from Shutdown To Normal SD low to high transition to input Operation monitoring enabled Note 1 All units are 100 production tested at TA 125 C Limits over the operating temperature range are guaranteed by correlation to the 125 C tests Note 2 The total supply current is the sum of the current flowing into VL BAT and BATREF Note 3 VrH VrH HIGH VrH Low 2 Note 4 VTH_HYS VrH HIGH VTH LOW Note 5 Wetting current rise fall time is measured as the time from 10 to 90 of the maximum wetting current Note 6 Guaranteed by design 4 AVLAZCLAI Automotive Contact Monitor and Level Shifter Test Circuits Timing Diagrams SO EN 4 5 lt gt I 1 gt SDO MSB OUT X i LSB OUT i 1 D i Figure 1 SPI Timing Characteristics MAXIM MAX13036 500 j Vor 0 1VL Figure 2 SDO Enable Disable Test Circuit and Timing Diagram 5 9EOELXVIN MAX13036 Automotive Contact Monitor and Level Shifter Typical Operating Characteristics VL 3
4. WEN bit to enable wetting currents on all channels and clear the WEN bit to dis able wetting currents Even with wetting currents glob ally enabled the wetting currents and sense resistors on INO and can still be turned off with the WEND bit see Table 4 Bit 10 INO and IN1 Wetting Current Enable WEND The WEND bit is used to turn on wetting currents and sense resistors on inputs INO and IN1 Set the WEND bit to enable wetting currents on INO and IN1 and clear the WEND bit to turn off the wetting current and sense resistors on INO and IN1 When the wetting currents and sense resistors are disabled WEND 0 INO and IN1 are configured as direct inputs with level shifted outputs on DOO and DO1 DOO and DO1 can only be used as level shifted outputs in normal mode and are tri stated in scan mode see the Scan Mode section Note that both the WEN and WEND bits need to be set for wetting currents to be enabled on INO and IN1 see SWITCHES ARE SWITCH POLLED FOR 250us DEBOUNCE IN STARTS 1 m 4 tscan p gt 1 1 1 GND CONNECTED SWITCH INPUT x SWITCH CLOSES STATUS REGISTERS AND INT ARE UPDATED AFTER Figure 6 Switch Sampling in Scan Mode 16kQ SENSE RESISTOR IN2 IN7 WETTING CURRENT IN2 IN7 AVLAZCLAVI 9 0 LXVIN MAX13036 Automotive Contact Monitor and Level Shifter Table 5 Switch Configuration Controlled by M1 and
5. mode only Short HYST to ground to obtain the maximum hysteresis of 0 5 x VBATREF The approximate formula for hysteresis is given below 43 M 0 166 123 RHYST KQ VBATREF To reduce power consumption the adjustable hystere sis can be disabled by setting SC2 SC1 SCO 1 1 0 in the command register When the adjustable hystere sis is disabled the hysteresis is set to 0 166 x VBATREF Switch Debounce and Deglitch The switch inputs INO IN7 share a common program mable debounce timer to increase the noise immunity of the system in normal and scan mode The switch debounce time is set by connecting a capacitor between the input and ground The minimum value of this capacitor is 500pF and the maximum value is 10nF corresponding to a debounce time of 5ms to 100ms respectively To calculate other debounce times the following formula should be used C nF 5 10 All switch input glitches of less than 20us in duration are automatically rejected by the MAX13036 Debounce in Normal Mode When a change of state occurs at the switch input the debounce timer starts If the new state is stable for at least the status register is updated and an inter rupt is generated if enabled If the input returns to its previous state before the debounce time has elapsed an interrupt is not generated and the status register is not updated Debounce in Scan Mode A change of state at the swit
6. reserves the right to change the circuitry and specifications without notice at any time 18 Maxim Integrated Products 120 San Gabriel Drive Sunnyvale CA 94086 408 737 7600 2007 Maxim Integrated Products MAXIM is registered trademark of Maxim Integrated Products Inc
7. 100Hz ioc i g ADJUSTABLE HYSTERESIS ON E ADJUSTABLE HYSTERESIS 2 7 8 Vino Vino OENE i 6 5V div 5V div 1 i i 5 4 1 5 4 Vpoo i 2V div Vpoo i 2 2V div 1 i 1 i i i i i i i i 0 40us div 2ms div 0 200k 400k 600k 800k 1M Ruyst Q 6 MAAKLM Automotive Contact Monitor and Level Shifter Typical Operating Characteristics continued VL 3 3V BAT 14V SD VL Rwet 61kQ 90k 4700pF TA 25 C unless otherwise noted SWITCHING THRESHOLD vs TEMPERATURE SWITCHING THRESHOLD vs 10 5 25 ADJUSTABLE HYSTERES A ADJUSTABLE HYSTERESIS OFF E _ 9 8 _ 2 E a 3 5 8 5 15 Lu E E RISING co co gt 7 10 Rr ond gt gt E 5 5 6 5 5 0 40 25 10 5 20 35 50 65 80 95 110 125 6 10 14 18 22 26 TEMPERATURE C Vear V INPUT WAVEFORM IN SCAN MODE SCAN MODE WTOFF WEN 0 WEND 1 DEBOUNCE TIME vs TEMPERATURE 55 SCANNING PERIOD 2ms 54 INPUT SWITCH OPEN 53 SENE 52 VIN f 5V div 50 uu 1 47 8 45 a 44 43 42 4 400us div 40 25 10 5 20 35 50 65 80 95 110 125 TEMPERATURE C DEBOUNCE TIME vs BAT
8. 3V BAT 14V SD VL Rwet 61kQ 90k 4700pF Ta 25 C unless otherwise noted WETTING CURRENT PULSE WETTING CURRENT vs WETTING CURRENT vs Rwet NORMAL MODE WTOFF 0 WEN WEND 1 40 2 6 5 5 z 2 4 ONNECTED SWI M 25 8 E 2 INT a 40 amp 1 2V div GND CONNECTED SWITCH lt gt c o 0 1 E AT CONNECTED SWITCH 2 E 40 CM 20mA div ONNECTED SWI 20 4 5 30 6 6 10 14 18 22 26 20ms div Vgar V Rwer BAT CURRENT vs TEMPERATURE BAT CURRENT vs TEMPERATURE BAT CURRENT vs TEMPERATURE NORMAL MODE SHUTDOWN MODE SCAN MODE 100 x 5 30 80 ADJUSTABLE HYSTERESIS ON E 4 8 25 E SCANNING PERIOD 70 b 8 E lt s gt 2 15 ADJUSTABLE HYSTERESIS OFF 8 SCANNING PERIOD an 10 20 1 5 10 0 0 0 40 25 10 5 20 35 50 65 80 95 110125 40 25 10 5 20 35 50 65 80 95 110 125 40 25 10 5 20 35 50 65 80 95 110 125 TEMPERATURE C TEMPERATURE C TEMPERATURE C TYPICAL INO DRIVING TYPICAL INO DRIVING NORMAL MODE WTOFF WEN WEND 0 NORMAL MODE WTOFF WEN WEND 0 HYSTERESIS vs Ruysr MAX13036 toc07 i MAX13036 toc08 8 2 f
9. 88 oN KIT VALUATI a AVAILABLE General Description The MAX13036 automotive contact monitor and level shifter monitors and debounces eight remote mechanical switches and asserts an interrupt INT if a switch changes state The state of each switch is sampled through an SPI interface by reading the status register and any switch can be prohibited from asserting an inter rupt by writing to the command register Four of the switch inputs are intended for ground connected switch es INO IN3 and the other four inputs INA IN7 are programmable in groups of two for either ground con nected or battery connected switches Two switch inputs INO IN1 have direct level shifted outputs DOO DO1 to be used for PWM or other timing based signals Switch input thresholds are set to 5096 of the voltage applied to BATREF The threshold hysteresis is set by connecting an external resistor from HYST to ground The MAX13036 supplies an adjustable wetting current to each closed switch to clean mechanical switch contacts that are exposed to adverse conditions The MAX13036 operates with a 6V to 26V battery volt age applied to BAT A separate 2 7V to 5 5V logic sup ply input VL sets the interface voltage The MAX13036 is available in a 5mm x 5mm 28 pin TQFN package and operates over the 40 C to 125 C temperature range Applications Electric Sunroofs Other Control ECUs Body Computers Window Lifters Seat Movers Pin Configur
10. C1 SC0 1 1 1 or 1 1 0 Scan mode is entered when the scanning period bits are set for a peri odic scanning time as shown in Table 3 Shutdown mode is entered by driving the shutdown input SD low The default mode after power up is scan mode when SD high with a scan period of 64ms Normal Mode Continuous Scanning In normal mode the input sense resistors are always connected to the switch inputs to detect any input status change except INO and IN1 when WEND 0 Wetting currents are enabled according to the WEN WEND and WTOFF bits in the command register If adjustable hys teresis is not required this feature can be disabled to reduce power consumption see the Typical Operating Characteristics by setting the scanning period bits in the 14 Ground Battery Ground Ground command register to SC2 SC1 SCO 1 1 0 hysteresis is set to 0 166 x VBATREF when adjustable hysteresis is disabled Scan Mode In scan mode each sense resistor is connected for a finite duration of 250us typ and is repeated at a period according to the scanning period bits SC2 SC1 and SCO see Table 3 All input resistors are connected simultaneously and the inputs are polled at the same time Scan mode reduces the current consumption from BAT to 17pA typ when all external switches are open and the scanning period is 64ms Wetting currents if enabled are applied to closed switches during the polling time of 250
11. MO IN7 AND IN6 SWITCH CONFIGURATION Ground IN5 AND IN4 SWITCH CONFIGURATION Ground IN3 INO SWITCH CONFIGURATION Ground Ground Battery Ground Battery Battery Table 4 The DOO and DO1 outputs are tri stated when WEND 1 When programmed as direct inputs WEND 0 any input changes on INO and IN1 are not reflected by the status register Bits 9 and 8 Switch Configuration for IN7 IN4 M1 The M1 and MO bits set the switch configuration in groups of two for IN7 through IN4 see Table 5 Set M1 to configure IN7 and IN6 for battery connected switches and clear M1 for ground connected switches Set MO to configure IN5 and INA for battery connected switches and clear MO for ground connected switches Bits 7 0 Interrupt Enable for IN7 INO 7 The P7 through PO bits allow independent control of whether inputs IN7 through INO generate an interrupt INT Set any bit to disable interrupts on the corre sponding input and clear the bit to enable interrupts on the corresponding channel An interrupt is asserted when any input configured for interrupts changes state INO and IN1 do not generate an interrupt when confi gured as direct inputs WEND 0 Operating Modes The MAX13036 features three modes of operation nor mal mode scan mode and shutdown mode Normal mode is entered when the scanning period bits in the command register are configured for continuous scan ning SC2 S
12. VOLTAGE DEBOUNCE TIME vs 55 12 54 2 8 53 8 8 52 5 10 a 51 T 50 8 4g 48 m 47 6 ZA 4 a amp 45 B 4 M 43 42 2 40 6 10 14 18 22 26 O 2000 4000 6000 8000 10000 Vear V Crprg pF 7 9EOELXVIN MAX13036 Automotive Contact Monitor and Level Shifter Pin Description FUNCTION 1 Connec itch connected to GND IN1 can be programmed as a direct ifted output on he Mechanical Switch Inputs INO IN7 section 6 Con SWi D or BAT 7 Con o a swi ND or BAT No Connection Not internally connected Hysteresis Input Connect HYST to GND with a 0 to 900kQ resistor to set the input voltage hysteresis on INO IN7 Wetting Current Input Connect a 30kQ to 330kQ resistor from WET to GND to set the wetting current on 10 WET INO IN7 11 TDEB Switch Debounce Time Input Connect a 500pF to 10nF capacitor from TDEB to GND to set the switch 2 debounce time GND 13 OT Overtemperature Warning Output OT is an open drain output that asserts low when the thermal warning threshold is exceeded 14 Interrupt Output INT is an open drain output that asserts low when one or more of the INO IN7 inputs state and is enabled for interrupts PI Chip Select Input Drive CS low to enable clocking of data into and out of the MAX13036 SPI data is pis into the MAX13036 on the rising edge of CS Serial Data Output SPI data is output on SDO on the rising edges of CLK while CS i
13. and register A pullup resistor to VL is needed on INT INT is cleared when CS is driven low for a read write operation and Level Shifter The INT output will still assert when VL is absent provid ed that it is pulled up to a different supply voltage Thermal Protection OT The MAX13036 features thermal protection that pre vents the device from being damaged by overheating When the internal temperature of the device exceeds the thermal warning threshold of 170 C typ all wet ting currents are disabled The MAX13036 returns to normal operation after the internal temperature decreases below 155 C typ The thermal shutdown does not activate below 150 C The thermal protec tion feature is disabled when WEN or when all inputs are open An open drain active low output OT asserts low when the internal temperature of the device rises above the thermal warning threshold OT is immediately cleared when the CS input is driven low for write read opera tions regardless of whether the temperature is above the threshold or not The overtemperature status of the MAX13036 can also be monitored by reading the OT bit in the status register The OT bit is set when the internal temperature rises above the temperature threshold and it is cleared when the temperature falls below the tem perature hysteresis level This allows a microprocessor to monitor the overtemperature status even if the OT o
14. ation TOP VIEW poo 22 GND f 24 MAXUM MAX13036 4 BATREF 25 BAT 26 TQFN CONNECT EXPOSED PADDLE TO GROUND MAKIM MA Automotive Contact Monitor and Level Shifter Features 6V 26V Operating Voltage Range 42V Compatibility on BAT Inputs Withstand Reverse Battery Withstands Dynamic Battery Voltage Drop While VL is Present Ultra Low Operating Current 17pA typ in Scan Mode Resistor Adjustable Switching Hysteresis CMOS Compatible Logic Outputs 2 7V min Built In Switch Debouncing Interrupt Output Immunity to Transients High Modularity Thermal Protection 8kV HBM ESD Protection on INO IN7 Without External Components Two Inputs INO IN1 Programmable as Direct Outputs Four Inputs IN4 IN7 Programmable for BAT or GND Related Switches Ordering Information PIN PKG PACKAGE CODE 28 TQFN EP 40 C to 125 C nk 5mm PART TEMP RANGE 1 72855 8 Denotes lead free package EP Exposed paddle Typical Application Circuit appears at end of data sheet SPI is a trademark of Motorola Inc Maxim Integrated Products 1 For pricing delivery and ordering information please contact Maxim Dallas Direct at 1 888 629 4642 or visit Maxim s website at www maxim ic com 9EOELXVIN MAX13036 Automotive Contact Monitor and Level Shifter ABSOLUTE MAXIMUM RATINGS All voltages referenced to GND
15. ch input causes the device to automatically enter normal mode and the debounce timing to start The device remains in normal mode as long as the input state differs from the previous state As soon as the debounce time ends the status register is updated an interrupt is generated and the device re enters scan mode If the input returns to its previous state before the end of the debounce time the device re enters scan mode an interrupt is not generated and the status register is not updated MAXIM Automotive Contact Monitor Wetting Current WET 13036 features adjustable wetting current to any closed switch to clean switch contacts that are exposed to adverse conditions The wetting current is set by connecting a 30kQ to 330kQ resistor from WET to ground A 30kQ resistor corresponds to a wetting current of 40mA typ and a 330k resistor corre sponds to a 7 5mA typ wetting current See the Typical Operating Characteristics section for the rela tionship between the wetting current RwET The WEN and WEND bits in the command register enable and disable the wetting currents and the WTOFF bit allows the wetting current to be activated for a dura tion of 20ms typ see the Command Register section Disabling wetting currents or limiting the active wetting current time reduces power consumption The default state upon power up is all wetting currents disabled Wetting current is activated on closed switche
16. configured for direct inputs All switch inputs have internal 16kQ sense resistors to detect switch transitions Inputs configured for ground connected switches are pulled up to BAT and inputs configured for battery connected switches are pulled down to GND Figure 3 shows the switch input structure for INO and IN1 INO and IN1 can be programmed as direct inputs with level shifted outputs DOO and DO1 by clearing the WEND bit in the command register nor mal mode only When programmed as direct inputs INO and IN1 can be used for PWM or other signaling Clearing the WEND bit disables the sense resistors and wetting currents on INO and IN1 When programmed as direct inputs the status of INO and IN1 is not reflected in the status register and interrupts are not allowed on these inputs Switch Threshold Levels and Hysteresis BATREF HYST Input thresholds for the remote switches are 50 of the voltage applied to BATREF The BATREF input is typi cally connected to the battery voltage before the MAXIM Vgar MAX13036 CONTROL LOGIC WETTING CURRENT o INO IN1 NOTES WETTING CURRENT AND PULLUP DOWN RESISTORS ARE CONTROLLED BY THE WEN AND WEND BITS IN THE COMMAND REGISTER SEE TABLE 4 Figure 3 Input Structure of INO and IN1 10 reverse battery protection diode The MAX13036 fea tures adjustable hysteresis on the switch inputs by con necting an external O to 900kQ resistor from HYST to ground normal
17. dance in Shutdown VSD OV VIN_ 14V LOGIC LEVELS SDO DOO DO1 Output Voltage High SDO DOO DO1 Output Voltage Low INT OT Output Voltage Low VINTL Source current 2mA Sink current 4mA Sink current 4mA SD Input Leakage Current lL SD VSD VBAT 12V SD Input Voltage Low VIL_SD B EE SD Input Voltage High SD CS CLK SDI Input Voltage High CS CLK SDI Input Voltage Low VIL VIH liL CS CLK Input Leakage Current INT OT Leakage Current loL SDI Input Impedance THERMAL SHUTDOWN RsDI Thermal Shutdown Temperature Thermal Shutdown Hysteresis 9EOELXVIN MAX13036 Automotive Contact Monitor and Level Shifter TIMING CHARACTERISTICS VL 2 7V to 5 5V BAT 6V to 26V SD VL TA 40 C to 125 C unless otherwise noted Typical values are at VL 3 3V BAT 14V Ta 25 C Note 1 PARAMETER SYMBOL CONDITIONS INO to DOO Propagation Delay IN1 to DO1 Propagation Delay VBAT 14V nput rise fa CLK Frequency 3 0V Falling Edge of CS to Rising of CLK Required Setup Time Falling Edge of CLK to Rising Edge of CS Required Setup Time SDI Valid to Falling Edge of CLK ired Setup Time ing Edge of CLK to SDI ired Hold Time tSI HOLD e From Falling Edge of CS to O Low Impedance o 5 5V Fi e From Rising Edge of CS to SDO High Impedance Time from
18. dge of CLK Serial data on the SDI input is latched into the shift register on the falling edge of CLK On the rising edge of CS the contents of the shift register are copied to the command register see Figure 5 The status and command registers are 16 bits wide so it is essential to clock a total of 16 bits while CS is low for the input and output data to be valid When CS is high the SDO out put is high impedance and any transitions on CLK and SDI are ignored The INT and OT flags are cleared on the CS falling edge Input status changes occurring during the CS reading writing operation are allowed If a switch status changes when CS is low the interrupt is asserted as usual This allows the part to be used even if VL is absent provided that the INT output is pulled up to another supply voltage Status Register The status register contains the status of the switches connected to IN7 through INO and it also contains an overtemperature warning bit see Table 1 The status register is accessed through an SPI compatible master Table 1 Status Register BIT 15 14 13 12 11 10 9 Notes Bits 15 8 Switch 7 Through 0 Status SW7 SWO SW7 through SWO reflect the status of the switches connected to inputs IN7 through INO respectively Open switches are returned as a 0 and closed switch es are returned as a 1 Bit 7 Overtemperature Warning OT The OT bit returns a 1 when the internal temperature of the MAX13036 is abov
19. e the temperature warning threshold of 170 C typ The OT bit returns a 0 when the MAX13036 is either below the temperature threshold or it has fallen below the temperature hys teresis level following an overtemperature event Bits 6 0 Unused Bits 6 through O are unused and should be ignored Command Register The command register is used to configure the MAX13036 for various modes of operation and is accessed by an SPl compatible master see Table 2 The power on reset POR value of the command regis ter is 0 00 7 6 5 NAME sw7 swe sws swa sws swa swi Sw or Table 2 Command Register 15 14 13 12 WTOFF SC2 SC1 SCO 0 0 0 0 12 MAXIM Automotive Contact Monitor Notes Bit 15 Wetting Current Mode WTOFF Set the WTOFF bit to configure the wetting currents as continuous on closed switches Clear the WTOFF bit to configure the wetting current as a pulse where the wet ting current is turned on for a set duration of 20ms after a switch closes and the debounce is timed out After 20ms elapses the wetting current is turned off Either wetting current mode is only applicable to switches that have wetting currents enabled see WEN and WEND bits In scan mode the wetting currents are on for the polling time of 250us typ and are pulsed at the pro grammed scanning period When WTOFF
20. gs in the command register as well as input monitoring even when VL is missing pro vided that SD To reduce current consumption connect SD to BAT through a 470kQ resistor Having SD compatible with VL has the advantage of reducing input leakage current into SD when SD VL Applications Information Automotive Considerations Reverse Battery Tolerance The BATREF and INO IN7 inputs withstand voltages down to 45V without damage so that reverse battery is not an issue The BAT pin should be protected with a reverse battery diode as shown in the Typical Application Circuit The shutdown input SD can be controlled from a battery level source but should be protected against reverse battery in the application Wetting Currents and Power Dissipation It is important to consider the effects of wetting currents on the power dissipated by the MAX13036 For example assume all inputs are configured for a continuous wetting current of 25mA all external switches have an on resis tance of 1Q and the battery voltage is 16V If all switches are simultaneously closed the corresponding power dis sipated by the MAX13036 is 16V 25mA x 1Q x 25mA x 8 3 12W this is higher than the absolute maximum power dissipation of 2759mW at TA 70 C ESD Protection As with all Maxim devices ESD protection structures are incorporated on all pins to protect against electrostatic discharges encountered during handling and assembly The IN7 INO
21. inputs have extra protection against static electricity Maxim s engineers have developed state of the art structures to protect these pins against ESD of 8kV without damage and Level Shifter Human Body Model The MAX13036 IN7 INO pins are characterized for 8kV ESD protection using the Human Body Model Figure 7a shows the Human Body Model and Figure 7b shows the current waveform it generates when dis charged into a low impedance This model consists of a 100pF capacitor charged to the ESD voltage of inter est which is then discharged into the device through a 1 5kQ resistor Rc IM Rp 15002 DEVICE Cs L STORAGE UNDER 100pF CAPACITOR TEST CHARGE CURRENT DISCHARGE LIMIT RESISTOR RESISTANCE HIGH VOLTAGE DC SOURCE Figure 7a Human Body ESD Test Model Ip 100 PEAK TO PEAK RINGING 90 NOT DRAWN TO SCALE AMPERES 36 8 10 0 TIME 6 to CURRENT WAVEFORM Figure 7b Human Body Model Current Waveform Chip Information PROCESS BiCMOS 9EOELXVIN MAX13036 Automotive Contact Monitor and Level Shifter Typical Application Circuit 46V TO 26V C 42V LOAD DUMP MAXIM MAX13036 3 REGUL OUT 16 MAXUM Automotive Contact Monitor and Level Shifter Package Information The package drawing s in this data sheet
22. is set the wetting current continuously pulses at the programmed scanning period When WTOFF is cleared the wetting current pulses at the programmed scanning period but turns off after 20ms elapses Bits 14 13 12 Scanning Period SC2 SC1 SCO The SC2 SC1 and SCO bits are used to program the scanning period as depicted in Table 3 Switch inputs are simultaneously polled for a finite duration of 250us typ and polling occurs at a period selected through the SC2 SC1 and SCO inputs Figure 6 shows a timing diagram of switch scanning and sampling When the inputs are not being polled the sense resistors are dis con nected reducing the current consumption caused from polling closed switches For a continuous scan Table 3 Programmable Scanning Period Continuous Adjustable Hysteresis Off Continuous WETTING CURRENT INO IN1 16kQ SENSE RESISTOR INO IN1 and Level Shifter ning period SC2 SC1 SCO 1 1 1 or 1 1 0 the switch inputs are constantly being monitored and the sense resistors are always connected The state SC2 SC1 SCO 1 1 0 also disables adjustable hys teresis normally set by and fixes hysteresis at 0 166 x VBATREF When adjustable hysteresis is not needed it is recommended to disable this feature to reduce power consumption Bit 11 Global Wetting Current Enable WEN The WEN bit is a global enable for the wetting currents on all the channels Set the
23. may not reflect the most current specifications For the latest package outline information go to www maxim ic com packages A QFN THIN EPS 1 DETAIL A 035x45 A R 15 OPTIONAL TERMINAL TIP SEATING BDALLAS AVLALXL VI TILE PACKAGE OUTLINE 16 20 28 32 40L THIN QFN 5x5x0 8mm DOCUMENT CONTROL ND DRAWING TO SCALE 21 0140 17 9EOELXVIN MAX13036 Automotive Contact Monitor and Level Shifter Package Information continued The package drawing s in this data sheet may not reflect the most current specifications For the latest package outline information go to www maxim ic com packages pk TEA mu 55 44 5 5 EU qe pe et ES pe Tex Te PETEAR 200 220 200 m o looeloos ooeloos o looeloos 4 045 ove aos 655 3 300 320 320 l tiessn 1_ 220 320 e jeslossJoasjoes nan hes on oleas nano ozn ozs 55 310 320 D so soo s10 490 suo asot sco sao faso s ao rews 4 200 320 Ft enisi rinse sn n ser so suos Sen 5 315 5 335 315 25 335 Pheer reossu s 15 225 335 315 225 335 t 30 0 40 050 45 0 55 ce
24. nt VL 5 5V VBAT 14V BAT Supply Range VL 5V VpAT 14V continuous scan programmable hysteresis off Total Supply Current MO M1 1 WEND 1 INO IN7 unconnected CS VL SDI CLK GND Note 2 VBAT 14V scan mode SCO 0 ISUP_SCAN SC1 0 SC2 0 CS VL SDI CLK GND Note 2 VSD OV TA 25 C Total Supply Current in Shutdown VBAT 14V Total Supply Current in Scan Mode EF Input Leakage Current in own ET Mode VBATREF 14V Note 2 40 C to 125 C 2 4 0 1 IL_BATREF VSD OV VBATREF 14V EF Input Resistance RBATREF VBATREF 14V SWITCH INPUTS INO IN7 or programmable hysteresis 0 5 x 0 575 x Input Voltage Threshold Center isabled TREF VBATREF VBATREF Not 90kQ or programmable hysteresis ed Input Voltage Threshold Hysteresis Note 4 VTH_HYS T 90kQ 2 MAXIM Automotive Contact Monitor and Level Shifter ELECTRICAL CHARACTERISTICS continued VL 2 7V to 5 5V BAT 6V to 26V SD VL Ta 40 C to 125 C unless otherwise noted Typical values are at VL 3 3V BAT 14V Ta 25 C Note 1 PARAMETER SYMBOL CONDITIONS Switch State Sense Resistor Wetting Current Rise Fall Time Wetting Current RSENSE IWET_RISE_ FALL note RwET 61 RwET 30k 14V RWET 330kQ INO IN7 Input Impe
25. s held low SDO is tri stated when CS is high Serial Data Input SPI data is latched into the internal shift register on the falling edges of CLK while CS is held low SDI has an internal 100kQ pulldown resistor SPI Serial Clock Inpu Logic Power Supply Input Connect to a positive 2 7V to 5 5V power supply Bypass VL to ground with a O 1yuF capacitor placed as close as possible to VL Data Output Channel 1 DO1 is the level shifted output of IN1 when WEND 0 normal mode only Data Output Channel 0 DOO is the level shifted output of INO when WEND 0 normal mode only Shutdown Input Drive SD low to place the MAX13036 into shutdown mode Drive SD high for normal operation SD is compatible with voltages up to 45 Battery Reference Input Switch thresholds are set to 5096 of the voltage applied to BATREF Connect BATREF to the system s battery supply voltage Battery Supply Input Connect BAT to a positive 6V to 26V battery supply voltage Bypass BAT to ground with a 0 1uF ceramic capacitor placed as close as possible to BAT In addition bypass BAT with a 10uF or greater capacitor Switch Input Channel 0 Connect INO to a switch connected to GND INO can be programmed as a direct input with a level shifted output on DOO see Mechanical Switch Inputs INO IN7 section Exposed Paddle Connect EP to GND 8 MAAKLM
26. s just after the debounce time The wetting current pulse starts after the debounce time A wetting current pulse is provided to all closed switches when a valid input change is detected Wetting current rise and fall times are controlled to enhance EMC performance There is one wetting current timer for all switch inputs Therefore it is possible to observe wetting pulses longer than expected whenever two switches turn on in sequence and are spaced out less than tweT In scan mode the wetting current is enabled during the polling pulse only When using wetting currents special care must be taken to avoid exceeding the maximum power dissipation of the MAX13036 see the Applications Information section Switch Outputs DOO DO1 DOO and DO 1 are direct level shifted outputs of the switch inputs INO and IN1 when the WEND bit of the command register is cleared and when operating in normal mode When configured as direct inputs the wetting currents and sensing resistors are disabled on INO and IN1 DOO and 001 are tri stated when the WEND bit is set or when operating in scan mode When programmed as direct inputs the status of IN and IN1 are not reflected in the status register an interrupts are not allowed on these inputs mE Interrupt Output INT INT is an active low open drain output that asserts when any of the switch inputs changes state as long as the particular input is enabled for interrupts set by clearing P7 PO in the comm
27. s o s 055 065 0 30 0 40 50 0 40 050 325 Pn e 3 DIMENSIONING amp TOLERANCING CONFORM TO ASME 14 5 1994 ALL DIMENSIONS ARE IN MILLIMETERS ANGLES ARE IN DEGREES N IS THE TOTAL NUMBER OF TERMINALS THE TERMINAL 1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO JESD 95 1 5 012 DETAILS OF TERMINAL 1 IDENTIFIER ARE OPTIONAL BUT MUST BE LOCATED WITHIN THE ZONE INDICATED THE TERMINAL 1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0 25 mm AND 0 30 mm FROM TERMINAL TIP ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS DRAWING CONFORMS TO JEDEC M0220 EXCEPT EXPOSED PAD DIMENSION FOR Te855 3 Te855 6 74055 1 AND 74055 2 Zh VARPAGE SHALL NOT EXCEED 0 10 me 1L MARKING IS FOR PACKAGE ORIENTATION REFERENCE ONLY 12 NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY DDALLAS AVI LEAD CENTERLINES TO BE AT TRUE POSITION AS DEFINED BY BASIC DIMENSION 1005 TILE PACKAGE OUTLINE 16 20 28 32 40L THIN QFN 5x5x0 8mm DOCUMENT CONTROL ND DRAWING SCALE 21 0140 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product No circuit patent licenses are implied Maxim
28. typ and are pulsed at the pro grammed scanning period When WTOFF is set the wetting current continuously pulses at the programmed scanning period When WTOFF is cleared the wetting current pulses at the programmed scanning period but turns off after 20ms elapses Inputs INO and IN1 cannot be used as direct inputs WEND 0 in scan mode When configured as direct inputs in scan mode the outputs DOO and are high impedance The quies cent current for a given scan mode can be calculated by the following formula 1 IBAT A 216x 14 uA tSCAN P ms Where SD 3 3V is the BAT current expressed microamps tSCAN_P is the scanning period expressed in miliseconds Shutdown Mode In shutdown mode all switch inputs are high impedance and the external switches are no longer monitored reduc ing current consumption on BAT to 2uA typ The MAX13036 resets upon entering shutdown mode and the contents of the command register are lost Exit shutdown mode by bringing the voltage on SD above 2 4V The SD input is compatible with voltages up to The MAX13036 takes 200us typ to exit shutdown at which point the command register is restored to its power up MAXIM Automotive Contact Monitor default 0x00 and the MAX13036 enters scan mode Note that SD is compatible with both VL and BAT voltage levels Having SD compatible to VBAT allows the MAX13036 to retain the settin
29. unless otherwise noted Continuous Current CS CLK SDI SDO DOO DO1 420mA MVM och 0 3V to 6 0V HBM ESD Protection 1 1 7 8kV BAT cv cute yet thet Some cate eect te 42V Continuous Power Dissipation Ta 70 C multilayer board BATHEF IN to nieder tentent 45V 28 Pin TQFN derate 34 5mW C above 70 C 2759mW BATREF IN to GND t45V Operating Temperature Range 40 C to 125 C 45 Junction 150 HYST WET TDEB OT INT 0 3V to 6 0V Storage Temperature Range 150 C CS CLK SDI 500 DOO DO1 0 3V to VL 0 3V Lead Temperature soldering 10s 300 C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied Exposure to absolute maximum rating conditions for extended periods may affect device reliability ELECTRICAL CHARACTERISTICS VL 2 7V to 5 5V BAT 6V to 26V SD VL TA 40 C to 125 C unless otherwise noted Typical values are at VL 3 3V BAT 14V Ta 25 C Note 1 PARAMETER SYMBOL CONDITIONS POWER SUPPLY VL Supply Range VL Supply Curre
30. utput has been cleared See Figure 4 for an exam ple timing diagram of the overtemperature alerts If desired the OT and INT outputs can be connected to the same P GPIO in a wired OR configuration to save uP pin The OT output still asserts when VL is absent provided that it is pulled up to a different supply voltage Serial Peripheral Interface CS SDO SDI CLK The MAX13036 operates as a Serial Peripheral Interface SPI slave device An SPI master accesses the MAX13036 by reading from a status register and writing to a command register Both registers are 16 bits long and are accessed most significant bit MSB first TEMPERATURE Figure 4 Example Timing Diagram of the Overtemperature Alerts 11 9 0 LXVIN MAX13036 Automotive Contact Monitor and Level Shifter SHIFT REGISTER IS COPIED TO COMMAND REGISTER E STATUS REGISTER IS COPIED TO SHIFT REGISTER 15 12 ul o 8 7 fel eL SCO WEN WEN D Mo P7 P6 P4 PA swo or i sero a 500 _ sw sw5 sw4 sw3 sw2 UNUSED Figure 5 SPI Read Write Example On the falling edge of CS the status register is immedi ately loaded to an internal shift register and the contents are transferred out of the SDO output on the rising e
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MAXIM MAX13036 handbook