MAX9937 Current-Sense Amplifier with Reverse-Battery Protection General Description Features The MAX9937 is a tiny current-sense amplifier designed Reverse Battery and Load-Dump Protection for unidirectional high-side current-sense applications. -20V to +40V This device addresses major areas of concern for various +4V to +28V Input Common-Mode Range applications including load-dump protection up to +40V, Flexible EMI Filtering reverse-battery protection, and filtering for EMI and tran- Low V : 1.2mV (max) sient performance. OS Low V Drift : 1V/C (typ) The MAX9937 also features a low input offset voltage of OS 1.2mV (max) at +25C with a low temperature drift of just 20A Supply Current 1V/C (typ). 350kHz, 3dB Small-Signal Bandwidth The MAX9937 is available in a 5-pin SC70 package and is rated over the -40C to +125C temperature range. Ordering Information PIN- TOP Applications PART TEMP RANGE PACKAGE MARK Battery Current Sense MAX9937AXK+T -40C to +125C 5 SC70 +ATB Fuse Box Current Sense ECU Current Monitor +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. Pin Configuration appears at end of data sheet. Typical Application Circuit R SENSE RS+ RS- LOAD R R RSP RSN 499 499 5V RSP RSN V CC GND V = 4V BAT TO 28V BIAS BLOCK MICROCONTROLLER MAX9937 OUT ADC R V OUT OUT GAIN = = R V RSP SENSE R OUT 10k 19-4233 Rev 1 9/14MAX9937 Current-Sense Amplifier with Reverse-Battery Protection Absolute Maximum Ratings RSP, RSN to GND Voltage Continuous ................-0.3V to +30V Thermal Limits (Note 1) RSP, RSN to GND Load-Dump Voltage Duration Continuous Power Dissipation (T = +70C) Multiple-Layer PCB A (V = 40V) with Typical Application Circuit ...................... 1s 5 SC70 (derate 3.1mW/C above +70C) ................246.9mW BAT RSP, RSN to GND Reverse-Battery Voltage Duration .............................................................................324C/W JA (V = -20V) with Typical Application Circuit ......Continuous .............................................................................115C/W BAT JC Differential Input Voltage (RSP - RSN) ..............................0.3V Operating Temperature Range ......................... -40C to +125C V to GND .........................................................-0.3V to +6.0V Junction Temperature ......................................................+150C CC OUT to GND ............................................. -0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C CC Output Short Circuit to Ground..................................Continuous Soldering Temperature (reflow) .......................................+260C Continuous Input Current into RSN, RSP* .......................50mA Continuous Input Current into OUT* ................................25mA Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a 4-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. *Junction temperature rating due to power dissipation must also be observed. 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 (V = 5V, V = V = 12V, V = (V - V ) = 0V, R = R = 500 , R = 10k , T = -40C to +125C. Typical CC BAT RS+ SENSE RS+ RS- RSP RSN OUT A values are at T = +25C, unless otherwise noted. See the Typical Application Circuit.) (Note 2) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC CHARACTERISTICS Input Common-Mode Voltage V , RSP Inferred from CMRR test 4 28 V Range V RSN Supply Voltage Range V Inferred from PSRR test 2.7 5.5 V CC T = +25C 0.3 1.2 A Input Offset Voltage (Note 3) V mV OS T = -40C to +125C 1.6 A T = +25C 100 120 Common-Mode Rejection A CMRR V = +4V to +28V dB BAT Ratio T = +125C 90 A Power-Supply Rejection Ratio PSRR V = +2.7V to +5.5V 90 120 dB CC Quiescent Supply Current I V = 5V 20 55 A CC CC T = +25C 0.8 2 5.6 A Input Bias Current (Note 4) I , I A B+ B- T = -40C to +125C 0.65 6.5 A T = +25C 1 12 % A Input Bias Current I /I 2 x (I - I )/(I + I ) T = -40C to B B B+ B- B+ B- A Mismatch 15 % +125C T = +25C, V = 0V 0.01 1 I + A CC RSP Input Current in Shutdown A I RSN T = -40C to +125C, V = 0V 10 A CC Voltage Gain Gain = R /R 20 V/V OUT RSP T = +25C 0.2 1.5 A Voltage Gain Error (Notes 3, 5) % T = -40C to +125C 2.0 A Maxim Integrated 2 www.maximintegrated.com