MAXIM MAX9621 handbook
Contents
1. Oro pertains to the package regardless of RoHS status PACKAGE TYPE PACKAGE CODE OUTLINE NO LAND PATTERN NO 10 uMAX U10 2 21 0061 90 0330 4X S x 10 INCHES MILLIMETERS MIN MAX MIN MAX 0 043 1 10 MARKING A1 0 002 0 006 0 05 0 15 2 0 030 0 037 0 75 0 95 01 0 116 0 120 2 95 3 05 02 0 114 0 118 2 89 3 00 1 0 116 0 120 2 95 3 05 E2 0 114 0 118 2 89 3 00 H 0 187 0 199 475 5 05 E L 0 0157 0 0275 0 40 0 70 M L1 0 037 REF 0 940 REF b 0 007 0 0106 0 177 0 270 1 e 0 0197 BSC 0 500 BSC c 10 0035 0 0078 0 090 0 200 BOTTOM VIEW S 0 0196 REF 0 498 REF o 6 0 6 Pkg Codes U10 2 U10CN 1 FRONT VIEW NOTES gv DRAWING NOT TO SCALE D amp E DO INCLUDE MOLD FLASH MOLD FLASH OR PROTRUSIONS NOT TO EXCEED 0 15 006 CONTROLLING DIMENSION COMPLIES TO JEDEC 187 LATEST REVISION VARIATION BA MARKING SHOWN IS FOR PKG ORIENTATION ONLY ALL DIMENSIONS APPLY TO BOTH LEADED lt gt AND PKG CODES MILLIMETERS GAGE PLANE E1 SIDE VIEW _MAXIM PACKAGE OUTLINE 10L uMAX uSOP APPROVAL 21 CONTROL NO 21 0061 REV IL 14 MAXIM Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Revision Hist2. TION KIT ALUA AVAILABL General Description The MAX9621 is a continuation of the Maxim family of Hall effect sensor interfaces that already includes the MAX9921 The MAX9621 provides a single chip solution to interface two 2 wire Hall effect sensors to low voltage microprocessors uP through either a digital output for Hall effect switches or an analog output for linear infor mation or both The MAX9621 protects the Hall sensors from supply transients up to 60 at the BAT supply Normal operating supply voltage ranges from 5 5V to 18V If the BAT sup ply rises above 18V the MAX9621 shuts off the current to the Hall sensors When a short to ground fault condition is detected the current to the Hall input is shut off and the condition is indicated at the analog output by a zero current level and a high digital output The MAX9621 provides a minimum of 50us blanking time following Hall sensor power up or restart The open drain digital outputs are compatible with logic levels up to 5 5V The MAX9621 is available in a 3mm x 5mm 10 pin UMAX package and is rated for operation in the 40 C to 125 C temperature range Applications Window Lifters Seat Movers Electric Sunroofs Seatbelt Buckles Door Power Locks Ignition Key Steering Column Speed Sensing Typical Application Circuit appears at end of data sheet is a registered trademark of Maxim Integrated Products Inc MAXIM AVLA
3. Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs ABSOLUTE MAXIMUM RATINGS Layer Board 444 4mW 707 3mW dissent toe Re dis 40 to 125 JUNCTION Temp rature ater teen 150 als 65 to 160 300 BATIO GND etie dde 0 3V to 60V Continuous Power Dissipation for a Single ISET TOBAT 2 0V to 0 3V TA 70 C IN1 IN2 to 3V to lower of 60V or VBAT 1V 10 Pin MAX derate 5 6mW C above AOUT1 DOUT1 AOUT2 DOUT2 Continuous Power Dissipation for a Multilayer Board SLEEP to GND ecc pete y i epe 0 3V to 6V TA 70 C Short Circuit Duration 10 Pin MAX derate 8 8mW C above 4 AOUT1 DOUT1 AOUT2 DOUT2 to GND Operating Temperature Range or to 5 5V 1 Continuous CurrentImto INT 2 Et reete te 100mA Storage Temperature Range Current In to Any Other dt 20 Lead Temperature soldering 10s Soldering Temperature reflow n 260 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
4. 1800 50 25 0 25 50 75 100 125 TEMPERATURE C SUPPLY VOLTAGE V RESPONSE TO SHORT TO GROUND MAX9621 toc21 REENERGIZING OF THE HALL INPUT FROM OPEN CIRCUIT CONDITION MAX9621 toc22 Y eee ee Vint viru eas Vaourt Vii Vpourt lint 777970 M ES VAOUTI WEGE NEN NR 400ns div 100us div STARTUP OF IN_ AOUT_ STARTUP OF IN_ DOUT_ FROM SHUTDOWN FROM SHUTDOWN 13 3 EM ag 6 M VSLEEP VSLEEP ViNt lin lini Vaour Vpouri 10us div AVLAXLAH 20us div Lc96X VIN MAX9621 Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Pin Configuration MAXIM MAX9621 Pin Description PIN NAME FUNCTION 1 BAT Battery Power Supply Connect to the positive supply through an external reverse polarity diode Bypassed to GND with O 1uF capacitor Current Setting Input Place a 1 resistor RSET between BAT and ISET to set the desired input current 2 ISET threshold range for the DOUT_ outputs See the Typical Operating Characteristics section for the correct value of RsEr for the desired range Make no other connections to this pin All routing must have low parasitic capacitance See the nput Current Thresholds and Short to Ground section Hall Effect Sensor Input 1 Supplies current to the Hall sensor and monitors the current level drawn to 3 IN 1 determine
5. for extended periods may affect device reliability DC ELECTRICAL CHARACTERISTICS VBAT 13 6V VSLEEP 5V IN1 IN2 no connection RSET 61 9kQ to BAT 10kQ at DOUT1 and DOUT2 RL 5kQ to GND at AOUT1 and AOUT2 unless otherwise noted TA 40 C to 125 C Typical values are at TA 25 Note 1 PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS GENERAL BAT Supply Range VBAT Guaranteed by functional test of 55 18 V and ormal mode 1 mA BAT Supply Current BAT ISD VSLEEP OV 1 10 UA VBAT 5 5V at and IN2 0 59 126 Hall Input Voltage Dropout V pies V all Input Voltage Dropou D 9 a VBAT 5 5V at IN1 and IN2 0 86 1 86 IN 20mA hine Model ESD Protection V Human Body Model 2000 INPUT THRESHOLDS FOR DOUT1 DOUT2 SWITCHING Input Current for Output High RSET 95 3kQ 77 mA Note 2 RSET 52 3 14 Input Current for Output Low RSET 95 3kQ 5 liL mA Note 2 RSET 52 3kQ 9 Input Current Hysteresis for Peak to peak as percent of average high 8 High Low Detection IN HYS low threshold Note 2 Channel to Channel Input High threshold 0 02 Threshold Variation Low threshold 0 02 A short to GND is not a sustained Short Circuit Current Limit Isc condition Hall input reverts to 50uA when 20 mA detected Note 2 AOUT1 AOUT2 ANALOG OUTPUTS Current Gain for AOUT1 and AOUT2 Outputs GI
6. magnetic threshold of the Hall sensor is exceeded A partial list of Hall switches that can be used with the MAX9621 is given in Table 2 Input Current Threshold Precision To get the best input current threshold precision it is rec ommended that the RSET resistor be directly connected to the BAT pin A true Kelvin type connection is best MAXIM Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Typical Application Circuit BATTERY 5 5V TO 18V OPERATING 60V WITHSTAND R REFERENCE SLEEP MODE 1 8V TO 5 5V 10k CONTROL jl Ww ECUCONNECTOR 077 INPUT REMOTE SHORT GROUND DETECTION FILTER MAXIM MAX9621 TAN MAXIM FILTER PROCESS BiCMOS MICROPROCESSOR Chip Information 13 Lc96X VIN MAX9621 Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Package Information For the latest package outline information and land patterns footprints go to www maxim ic com packages Note that a in the package code indicates RoHS status only Package drawings may show a different suffix character but the drawing
7. the high low state of the sensor Bypass to GND with a 0 01uF capacitor Connect an unused input to BAT pin Hall Effect Sensor Input 2 Supplies current to the Hall sensor and monitors the current level drawn to 4 IN2 determine the high low state of the sensor Bypass to GND with a 0 01uF capacitor Connect an unused input to BAT pin 5 GND Ground MAKII Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Pin Description continued PIN NAME FUNCTION 6 DOUT2 Open Drain Output Signal translated from Hall sensor 2 DOUT2 is high when the current flowing out of IN2 exceeds the input current threshold high and is low when less than the input current threshold low See Table 1 for output response to operating conditions 7 AOUT2 Analog Current Output Mirrors the current to the corresponding Hall sensor at IN2 When IN2 has been shut down due to a short to GND a current of zero is supplied to AOUT2 See Table 1 for output response to operating conditions To obtain a voltage output connect a resistor from AOUT_ to ground 8 DOUT1 Open Drain Output Signal translated from Hall sensor 1 DOUT1 is high when the current flowing out of IN1 exceeds the input current threshold high and is low when less than the input current threshold low See Table 1 for output response to operating conditions 9 AOUT 1 Analog Current Output Mirrors the current to the corresponding Hall sensor at I
8. 18 lt lt 2mA 0 05 mA mA Current Gain Error for AOUT1 AOUT2 Outputs GEI 5mA 14mA 02 447 2 MAAKLM Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs DC ELECTRICAL CHARACTERISTICS continued VBAT 13 6V VSLEEP 5V IN1 IN2 no connection RSET 61 9kQ to BAT 10kQ at DOUT1 and DOUT2 RL 5kQ to GND at AOUT1 and AOUT2 unless otherwise noted TA 40 to 125 C Typical values are at TA 25 Note 1 PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Inferred from measurements at Input Referred Current Offset los keen pA 120 120 _ VBAT 5 5V 14mA 085 16 AOUT Dropout Voltage for 596 current V reduction IIN 20mA 1 09 1 75 AOUT Output Impedance 500 MO LOGIC DOUT1 DOUT2 Output Voltage Low DOUT1 _ DOUT2 VOL Sink current 2 1mA 0 4 V Three State Output Current DOUT1 DOUT loz VSLEEP OV OV lt VbOUT lt 5V 1 SLEEP Input Voltage High VIH 2 0 V Input Voltage Low VIL 0 8 V Input Resistance to GND RIN 50 100 AC TIMING CHARACTERISTICS Shutdown Delay from SLEEP IIH 14mA to GND time from SLEEP low t 33 40 46 Low to IN_ Shutoff SHDN to IN_ drop 500mV CL 20pF HS 14mA to GND time from at Mall tBL VIN 500mV until DOUT_ high CL 76 89 103 us 20pF Notes 2 3 IN Curre
9. 25 RESISTANCE kQ TEMPERATURE TEMPERATURE DELAY FROM IN TO DOUT FILTER DELAY DELAY DIFFERENCE BETWEEN CHANNELS MAXIMUM FREQUENCY ON vs TEMPERATURE vs TEMPERATURE HALL INPUTS vs TEMPERATURE 20 2 900 60 70 50 2 15 IN m H 50 40 E z E gt 10 S 2 i 5 5 30 amp 3 5 a 100 20 0 10 10 GE M M M NN E 25 0 25 50 75 100 125 25 0 25 50 75 100 125 TEMPERATURE TEMPERATURE TEMPERATURE IN PULSE LENGTH REJECTED BY FILTER INPUT DROPOUT VOLTAGE INPUT DROPOUT VOLTAGE TO DOUT vs TEMPERATURE vs TEMPERATURE VS VBAT 2 1 15 i E VgAT 5 51 2 IN1 Tam E i E 1 05 lint 14mA E E 16 PD NEGATIVE PULSE gI 0 85 12 P g 075 5 065 POSITIVE PULSE M X a 6 a 0 45 2 0 35 0 25 50 25 0 25 50 75 10 125 45 25 10 5 20 35 50 65 80 95 110125 550 800 1050 1300 1550 180 TEMPERATURE C TEMPERATURE C Vear V 6 MAXIM Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Typical Operating Characteristics continued VBAT 13 6V RSET 61 9kQ RL 5kQ to GND at AOUT_ VSLEEP 5V 25 C unless otherwise noted CURRENT GAIN vs SUPPLY VOLTAGE CURRENT GAIN vs TEMPERATURE 0 07 2 07 0 06 0 06 E 3 0 05 55 0 05 Lr Lr BS 0 04 004 03 0 03 550 800 1050 1300 1550
10. 3161 Allegro www allegromicro com t area added resistor wir infineon com wire Sleep Mode Sleep mode can be used in applications that do not continuously require the polling of the Hall sensors In such cases the uP can enable the MAX9621 for a short time check the sensor status and then put the MAX9621 back to sleep A blanking period follows upon exiting sleep mode Remote Ground The MAX9621 targets applications with 2 wire Hall effect sensors 2 wire sensors have connections for supply and ground The output level is signaled by means of modula tion of the current drawn by the Hall sensor from its supply The two threshold currents for high low are generally in the range of 5mA to 14 Thus the interfacing of a 2 wire sensor is not simply a matter of detecting two voltage thresholds but requires a coarse current sense function Because of the high side current sense structure of the MAX9621 the device is immune to shifts between the 12 sensor ground the ground of the MAX9621 and uP This ground shift immunity eliminates the need for a ground connection wire allowing a single wire interface to the Hall sensor Hall Effect Sensor Selection The MAX9621 is optimized for use with 2 wire Hall effect switches or with 3 wire Hall effect switches connected as 2 wire Figure 5 When using a 3 wire Hall sensor the resistor R is chosen so that the current drawn by the Hall sensor crosses the MAX9621 current threshold when the
11. HIGH LOW TO HIGH i 96 3 5 94 Jj Jj 92 HIGH TO LOW 25 AND 40 C 90 HIGH TO LOW 88 0 20 40 60 80 40 25 10 5 20 35 50 65 80 95 110 125 55 80 105 130 155 180 BAT VOLTAGE V TEMPERATURE BAT VOLTAGE V MAAXALAVI 5 Lc96X VIN Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Typical Operating Characteristics continued VBAT 13 6V RSET 61 9kQ RL 5kQ to GND at AOUT_ VSLEEP 5V TA 25 C unless otherwise noted INPUT BLANKING TIME AT RESTART HALL INPUT CURRENT THRESHOLDS FROM SLEEP MODE OR POWER UP IN CURRENT RAMP RATE AFTER vs ISET RESISTOR vs TEMPERATURE TURN ON vs TEMPERATURE 100 MAX9621 Boos 9 _ u E E 9 8 12 5 85 7 LOW TO H E 2 10 80 ce 6 2 75 5 8 HIGH 70 4 6 65 3 4 60 2 50 60 70 80 90 100 40 25 10 5 20 35 50 65 80 95 110125 40 25 10 5 20 35 50 65 80 95 110 1
12. N1 When IN1 has been shut down due to a short to GND a current of zero is supplied to AOUT1 See Table 1 for output response to operating conditions To obtain a voltage output connect a resistor from AOUT_ to ground Sleep Mode Input The part is placed in sleep mode when the SLEEP input is low for more than 40ps 10 SLEEP If the SLEEP input is low for less than 20 and then goes high the part restarts any Hall input that has been shut off due to a detected short to GND Any Hall input that is operational is not affected when SLEEP is cycled low for less than 20us There is an internal 100kQ pulldown resistance to GND Detailed Description The MAX9621 an interface between two 2 wire Hall effect sensors and a low voltage microprocessor sup plies and monitors current through IN1 and IN2 to two Hall sensors The MAX9621 complements Maxim s existing family of Hall effect sensor interfaces that includes the MAX9921 The MAX9621 provides two independent channels with two outputs for each channel a digital output and an analog output The digital outputs DOUT1 and DOUT2 are open drain and indicate a logic level that corresponds to the Hall sensor status DOUT1 or DOUT2 outputs high when the current out of IN1 or IN2 respectively exceeds the high input current threshold DOUT1 or DOUT2 MAXIM outputs low when the current flowing out of IN1 or IN2 respectively is lower than the low input current thres
13. ZIL AVI Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Provides Supply Current and Interfaces to Two 2 Wire Hall Effect Sensors 5 5V to 18V Operating Voltage Range Protects Hall Sensors Against Up to 60V Supply Transients 9 9 9 Low Power Shutdown for Power Saving Filtered Digital Outputs Analog Output Mirrors the Hall Sensor Current Hall Inputs Protected from Short to Ground Hall Sensor Blanking Following Power Up and Features LC96XVIN Restart from Shutdown and Short to Ground Operates with 3V Ground Shift Between the Hall Sensor and the MAX9621 2kV Human Body Model ESD and 200V Machine Model ESD at All Pins 3mm x 5mm 10 uMAX Package Ordering Information PART TEMP RANGE PIN PACKAGE MAX9621AUB T 40 C to 125 C 10 MAX MAX9621AUB V 40 C to 125 C 10 MAX Denotes a lead Pb free ROHS compliant package T Tape and reel V denotes an automotive qualified part REFERENCE Functional Diagram SLEEP MODE CONTROL FILTER INPUT MAXIM DETECTION MAX9621 FILTER Maxim Integrated Products 1 For pricing delivery and ordering information please contact Maxim Direct at 1 888 629 4642 or visit Maxim s website at www maxim ic com MAX9621
14. an of the threshold current limits lt 0 Y Yo 6 2013 x 10 5 units of 1 kQ To compute the typical input current thresholds from the mean input current it is necessary to obtain the hyster esis The following equation finds the hysteresis given the mean threshold current I lt 0 where 0 033463 in mA and 0 08414 mA mA Input current threshold high H 2 input current threshold low H 2 Application Information Use of Digital and Analog Outputs The digital output can be used to provide the uP with an interrupt signal that can represent a Hall sensor change of status DOUT1 and DOUT2 provide a time domain output filter for robust noise immunity See Figure 2 The analog output can be connected to an ADC with an appropriate load resistor and can be used to perform custom diagnostics 11 Lc96X VIN MAX9621 Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs MAXIM MAX9621 Figure 5 3 Wire Hall Effect Switches Configured as 2 Wire Table 2 A Partial List of Compatible Hall Switches PART NO MANUFACTURER WEBSITE COMMENTS HAL573 6 Micronas www micronas com 2 wire HAL556 560 566 Micronas www micronas com 2 wire HAL579 581 584 Micronas www micronas com 2 wire A1140 1 2 3 Allegro www allegromicro com 2 wire 3 wire optimized for 2 wire A
15. ational it is not affected The restart happens on the rising edge of SLEEP Input Current Thresholds and Short to Ground The input current high and low thresholds that determine the logic level of the digital outputs are adjusted by changing the RSET value When the RSET value changes the following parameters change as well IN HYS ISC BL tRAMP fMAX and PR lH HYS ISC tRAMP and fMAx are inversely pro portional to RSET decrease as RSET increases This inverse relationship is linear For example a 10 change in 1 RSET results in a 10 change in current parameters Conversely time and delay parameters are linear and directly proportional to RSET and a 10 change in RSET results in an 10 change in time parameters The difference between the maximum and minimum threshold current limits is the min max limit spread which is greater than the threshold hysteresis The min max spread and the hysteresis both change by the same per centage as the mean of the threshold current limits The following equation is useful for finding the mean of the threshold current limits given a value of RSET resistance MAXIM lt 0 1 10 0 Rxm is the mean of the threshold current limits R is the value of the RSET resistance in the constant lo 0 03717mA and the constant 0 001668 1 x mA The following equation is useful for finding the value of RSET resistance given a me
16. f the input remains loaded by the Hall switch The current required to power the Hall switch is shut off and only a 50pA pullup current remains The Hall input can be manually reenergized or it can be reener gized by the uP A 10us to 20us negative pulse at SLEEP restarts with a blanking cycle any Hall input that has been shut down due to the short to ground condition During startup or restart it is possible for a Hall input to charge up an external capacitance of 0 02uF without HALL INPUT SHORT TO GROUND FAULT tripping into a short to ground latched state During the short to ground fault DOUT1 and DOUT2 are high impedance pulled high by the pullup resistors while AOUT1 and AOUT are set to zero output current Manual Method for Reenergizing Hall Sensor and Means for Diagnosing an Intermittent Hall Sensor Connection Figure 3 shows the behavior of the MAX9621 when a Hall input is open Figure 4 shows the behavior of the MAX9621 when the open input is reconnected to a Hall sensor Figures 3 and 4 demonstrate how a short to ground Hall input can be reset Resetting a short to ground Hall input involves three steps 1 Relieve the short to ground at the Hall sensor 2 Disconnect the Hall input from the Hall sensor open input fault condition 3 Reconnect the Hall input to the Hall sensor The MAX9621 restarts the Hall input with a blanking cycle If the Hall input is disconnected from the Hall sensor for 10ms it al
17. gure 2 Hall Input Pulse Rejection 4 MAXIM Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Typical Operating Characteristics VBAT 13 6V RSET 61 9kQ RL 5 to GND at AOUT_ VSLEEP 5V TA 25 C unless otherwise noted BAT SUPPLY CURRENT vs IN OPERATING MODE BAT SUPPLY CURRENT vs Vgar IN OPERATING MODE BAT SUPPLY CURRENT vs IN OPERATING MODE 0 9 9 a 0 9 z 0 8 8 0 8 07 7 07 a amp amp tu 25 CE 2 06 06 06 lt lt eoa faa ea 05 5 0 5 04 4 04 19 0 19 5 20 0 205 210 190 19 5 20 0 20 5 21 0 19 0 19 5 20 0 20 5 21 0 BAT VOLTAGE V BAT VOLTAGE V BAT VOLTAGE V BAT SUPPLY CURRENT BAT SUPPLY CURRENT BAT SUPPLY CURRENT vs IN OPERATING MODE vs IN OPERATING MODE vs IN OPERATING MODE 10 0 1 0 E Ta 40 C 8 E 0 8 8 A 0 8 1 Lr a amp amp 06 08 06 c c e lt lt ea a 04 4 04 02 2 02 0 1 2 30 40 5 60 0 10 20 30 40 50 60 0 1 2 30 40 50 6 BAT VOLTAGE V BAT VOLTAGE V BAT VOLTAGE V BAT SUPPLY CURRENT HALL INPUT CURRENT THRESHOLDS HALL INPUT CURRENT vs IN SHUTDOWN MODE FOR HIGH LOW vs TEMPERATURE THRESHOLDS vs VpAT s 10 4 2 2 102 3 2 _ 3 a 5 100 H Low TO
18. hold DOUT1 and DOUT2 provide a time domain output filter for robust noise immunity See Figure 2 The analog outputs AOUT1 and AOUT2 mirror the cur rent flowing out to the corresponding inputs IN1 and IN2 with a nominal gain of 0 05mA mA Hall Sensor Protection from Supply Transients The MAX9621 protects the hall sensors from supply transients by shutting off current at INT and IN2 when the BAT voltage is 18V The digital outputs go low and analog outputs have zero output current When VBAT returns to the proper operating range both inputs restart following a blanking cycle Lc96X VIN MAX9621 Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Table 1 AOUT DOUT Truth Table CONDITION AOUT DOUT_ IN_ Short to GND 0 High Z IN Short to BAT or IN Open 0 Low SLEEP Low 0 High Z VBAT 18V 0 Low If IN_ is already shorted to BAT or open during power up DOUT_ goes to high Z until IN_ is loaded Hall Input Short to Battery Condition The MAX9621 interprets a short to battery when the volt age at IN1 or IN2 is higher than VBAT 100mV The digi tal outputs go low and the analog outputs are set to zero output current If IN1 or IN2 is more than 1V above VBAT it back drives current into BAT The MAX9621 restarts the Hall inputs when the Hall input is loaded again Hall Input Short to Ground The Hall input short to ground fault is effectively a latched condition i
19. lows the Hall input to be pulled up by the 50pA pullup current to register the open input fault condition Reconnecting the Hall input to the Hall sensor restarts the Hall input with a blanking cycle This provides a manual means of reenergizing a Hall input without having to resort to the to restart it This also demonstrates the behavior of an intermittent connection to a Hall sensor VBAT 25mV HALL INPUT OPEN CIRCUIT FAULT HALL INPUT DISCONNECTED FROM SENSOR 4 Figure 3 Hall Input Ramps to Open Circuit Fault When a Short to Ground Is Relieved 10 MAXIM Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs VBAT 25mV 14V Vpat 500mV 5mA us HALL INPUT RECONNECTED Pon TO HALL SENSOR Figure 4 Hall Input Reenergized When Open Input Is Reconnected to Hall Sensor Sleep Mode Input SLEEP The MAX9621 features an active low SLEEP input Pull SLEEP low for more than 40 to put the device into sleep mode for power saving In sleep mode the DOUT1 and DOUT outputs are high impedance and are pulled high by pullup resistors AOUT1 and AOUT are set to zero output current Hall Input Restart When an input has been shut down due to a short to ground cycle SLEEP for 10us to 20us to restart the input If the other input is oper
20. nt Ramp Rate After _ IN_ GND Note 2 3 6 5 6 7 mA us Delay from IN to DOUT Filter From to liL or from liL to Delay DEL CL 20pF Figure 1 Note 2 ae dem us Delay Difference Between e CHALL BYPASS 0 01 IIH 11 5mA Rising and Falling Edges of tDM ai 2 1 us Both Channels Delay Difference Between CHALL BYPASS 0 01UF 11 5mA Channels icc and liL 7 5mA CL 20pF sug ve Maximum Frequency on Hall CHALL BYPASS 0 01UF IIH 11 5mA Inputs and liL 7 5 CL 20pF Note 2 9d dis Maximum Analog Output Current During Short to GND IMAO 1 4 mA Fault IN Pulse Length Rejected by Figure 2 Note 2 78 115 146 ys Filter to DOUT Note 1 All DC specifications are 100 production tested at TA 25 C AC specifications are guaranteed by design at TA 25 Note 2 Parameters that change with the value of the Rser resistor liL IN HYS ISC tDEL 1 and Note 3 Following power up or startup from sleep mode the start of the blanking period is delayed 20us MAXIM 3 LE96XVIN MAX9621 Dual 2 Wire Hall Effect Sensor Interface with Analog and Digital Outputs Timing Diagrams APPROXIMATELY 100mA HALL SENSOR SHORT CIRCUIT OPEN APPROXIMATELY 100mA 5mA us APPROXIMATELY 1 4mA HALL SENSOR OPEN RESTART Figure 1 Timing Diagram Fi
21. ory REVISION REVISION PAGES NUMBER DATE DESCRIPTION CHANGED 0 11 09 Initial release 1 9 11 Added automotive qualified part 1 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 reserves the right to change the circuitry and specifications without notice at any time Maxim Integrated Products 120 San Gabriel Drive Sunnyvale CA 94086 408 737 7600 15 O 2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products Inc Lc96X VIN
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MAXIM MAX9621 handbook