19-1781; Rev 6; 2/11 Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain Features The MAX4376/MAX4377/MAX4378 single, dual, and quad precision high-side current-sense amplifiers are available in space-saving packages. They feature buffered voltage outputs that eliminate the need for gain-setting resistors and are ideal for today's notebook computers, cell phones, and other systems where current monitoring is critical. These precision devices are offered in three fixed-gain versions of 20, 50, and 100: GAIN SUFFIX 20 T 50 F 100 H For example, MAX4376TAUK is a single high-side amplifier with a gain of 20. High-side current monitoring is especially useful in battery-powered systems since it does not interfere with the ground path of the battery charger. The input common-mode range of 0 to +28V is independent of the supply voltage and ensures that the current-sense feedback remains viable even when connected to a battery pack in deep discharge. The full-scale current reading can be set by choosing the appropriate voltage gain and external-sense resistor. This capability offers a high level of integration and flexibility, resulting in a simple and compact currentsense solution. The MAX4376/MAX4377/MAX4378 operate over a supply voltage range of +3V to +28V, draw 1mA of supply current per amplifier, and operate over the full automotive temperature range of -40C to +125C. These devices have a wide bandwidth of 2MHz, making them suitable for use inside battery-charger control loops. The buffered outputs drive up to 2mA of output current into a ground-referenced load. The MAX4376 is available in a tiny 5-pin SOT23 package. The MAX4377/MAX4378 are available in spacesaving 8-pin MAX (R) and 14-pin TSSOP packages, respectively. o Low-Cost, Single/Dual/Quad, High-Side CurrentSense Amplifiers o 0.5% Typical Full-Scale Accuracy o +3V to +28V Supply Operation o Adjustable Current-Sense Capability with External Sense Resistor o Buffered Output Voltage with 2mA Drive o 1mA (typ) Supply Current o 2.0MHz Bandwidth (Gain = +20V/V) o Automotive Temperature Range (-40C to +125C) o High Accuracy +2V to +28V Common-Mode Range, Functional Down to 0V, Independent of Supply Voltage o Three Gain Versions Available +20V/V (MAX437_T) +50V/V (MAX437_F) +100V/V (MAX437_H) o Available in Space-Saving 5-Pin SOT23 (Single), 8-Pin MAX (Dual), and 14-Pin TSSOP (Quad) Applications Notebook Computers Current-Limited Power Supplies Fuel Gauges in PC General-System/BoardLevel Current Monitoring Battery Chargers Portable/Battery-Powered Systems Cell Phones Smart Battery Packages Automotive Current Detect Power Management Systems PA Bias Control MAX is a registered trademark of Maxim Integrated Products, Inc. Ordering Information TEMP RANGE GAIN (+V/V) PART PINPACKAGE TOP MARK MAX4376 T AUK+T 20 -40C to +125C 5 SOT23 ADOG MAX4376FAUK+T 50 -40C to +125C 5 SOT23 ADOH MAX4376HAUK+T 100 -40C to +125C 5 SOT23 ADOI MAX4376HAUK/V+T 100 -40C to +125C 5 SOT23 AFGO MAX4376TASA+ 20 -40C to +125C 8 SO -- MAX4376FASA+ 50 -40C to +125C 8 SO -- Ordering Information continued at end of data sheet. +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. Pin Configurations TOP VIEW + OUT 1 GND 2 5 RS- 4 RS+ MAX4376 VCC 3 SOT23 Pin Configurations continued at end of data sheet. ________________________________________________________________ Maxim Integrated Products 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. 1 MAX4376/MAX4377/MAX4378 General Description MAX4376/MAX4377/MAX4378 Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain ABSOLUTE MAXIMUM RATINGS VCC, RS+, RS- to GND ...........................................-0.3V to +30V OUT to GND ...............................................-0.3V to (VCC + 0.3V) Differential Input Voltage (VRS+ - VRS- ).................................8V Output Short Circuit to VCC ........................................Continuous Output Short Circuit to GND .....................................................1s Current into Any Pin..........................................................20mA Continuous Power Dissipation (TA = +70C) 5-Pin SOT23 (derate 7.1mW/C above +70C)............571mW 8-Pin MAX (derate 4.5mW/C above +70C) .............362mW 8-Pin SO (derate 5.88mW/C above +70C)................471mW 14-Pin SO (derate 8.33mW/C above +70C)..............667mW 14-Pin TSSOP (derate 9.1mW/C above +70C) .........727mW Operating Temperature Range .........................-40C to +125C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C Soldering Temperature (reflow) .......................................+260C 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 (VRS+ = 0 to 28V, VSENSE = (VRS+ - VRS- ) = 0V, VCC = +3.0V to +28V, RL = , TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = 25C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP UNITS Operating Voltage Range VCC Guaranteed by PSR test 3 28 V Common-Mode Input Range VCM Guaranteed by total OUT voltage error test 0 28 V Common-Mode Rejection CMR 2V VRS+ 28V, VSENSE = 100mV 90 VSENSE = 5mV, VRS+ > 2.0V, VCC = 12V 1 Supply Current per Amplifier Leakage Current ICC IRS+, IRSIRS+ Input Bias Current IRSFull-Scale Sense Voltage VCC = 0V, VRS+ = 28V OUT Low Voltage -400 60 VRS+ > 2.0V 0 120 VRS+ 2.0V -800 120 150 IOUT 2mA VOL A 60 A mV 6.75 0.5 VSENSE = 100mV, VCC = 28V, VRS+ = 28V (VCC - VOUT) mA 8 VRS+ 2.0V VSENSE = 100mV, VCC = 12V, TA = +25C, VRS+ = 12V OUT High Voltage (Note 4) 2.2 0 VSENSE Total OUT Voltage Error (Note 2) dB VRS+ > 2.0V VSENSE = 100mV, VCC = 12V, VRS+ = 12V 2 MAX 3.25 11 % VSENSE = 100mV, VCC = 28V, VRS+ = 28V, TA = +25C 0.5 5 VSENSE = 100mV, VCC = 12V, VRS+ = 0.1V 9 32 VSENSE = 6.25mV, VCC = 12V, VRS+ = 12V (Note 3) 7 VCC = 3V, IOUT = 2mA, VRS+ = 28V 0.9 1.2 V IOUT = 200A, VCC = VRS+ = 12V, VSENSE = 0V, TA = +25C 25 40 mV _______________________________________________________________________________________ Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain (VRS+ = 0 to 28V, VSENSE = (VRS+ - VRS- ) = 0V, VCC = +3.0V to +28V, RL = , TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = 25C.) (Note 1) PARAMETER Bandwidth SYMBOL BW Slew Rate SR Gain AV AV Gain Accuracy CONDITIONS VCC = 12V VRS+ = 12V CLOAD = 15pF Maximum Capacitive Load 2 VSENSE = 100mV (gain = +50V/V) 1.7 VSENSE = 100mV (gain = +100V/V) 1.2 VSENSE = 6.25mV (Note 3) 0.5 VSENSE = 20mV to 100mV, CLOAD = 15pF UNITS MHz 10 +50 MAX437_H +100 VSENSE = 10mV to 150mV, VCC = 12V, IOUT = 2mA, gain = 20 and 50, VRS+ = 12V MAX V/s +20 MAX437_T MAX437_F TA = TMIN to TMAX V/V 5.5 0.5 TA = +25C 2.5 % VCC = 12V, VRS+ = 12V, CLOAD = 15pF CLOAD TYP VSENSE = 100mV (gain = +20V/V) VSENSE = 10mV to 150mV, VCC = 20V, IOUT = 2mA, gain = 100, VRS+ = 12V OUT Setting Time to 1% of Final Value MIN TA = TMIN to TMAX 5.5 TA = +25C 0.5 VSENSE = 6.25mV to 100mV 400 VSENSE = 100mV to 6.25mV 800 2.5 ns No sustained oscillation Output Resistance ROUT VSENSE = 100mV Power-Supply Rejection PSR VRS+ > 2V, VOUT = 1.6V, VCC = 3V to 28V 1000 66 pF 5 90 dB Power-Up Time to 1% of Final Value VSENSE = 100mV, CLOAD = 15pF 2 s Saturation Recovery Time to 1% of Final Value VCC = 12V, VRS+ = 12V, CLOAD = 15pF, VSENSE = 100mV 1 s Reverse Recovery Time to 1% of Final Value VCC = 12V, VRS_ = 12V, CLOAD = 15pF, VSENSE = -100mV to +100mV 1 s Note 1: Note 2: Note 3: Note 4: All devices are 100% production tested at TA = +25C. All temperature limits are guaranteed by design. Total OUT Voltage Error is the sum of gain and offset errors. 6.25mV = 1/16 of 100mV full-scale sense voltage. VSENSE such that VOUT is in saturation. _______________________________________________________________________________________ 3 MAX4376/MAX4377/MAX4378 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VCC = VRS+ = 12V, VSENSE = 100mV, TA = +25C.) SUPPLY CURRENT (PER AMPLIFIER) vs. TEMPERATURE 0.85 MAX4376T 0.80 MAX4376H 0.75 0.70 0.65 1.0 1.0 MAX4376F 0.8 MAX4376T 0.6 0.4 0.60 MAX4376F 0.4 0.2 0.0 -0.2 -0.4 MAX4376H -0.8 0 0.50 10 15 20 25 -1.0 -50 30 -25 0 25 50 75 5 10 MAX4376H 4 3 MAX4376F 2 1 0 MAX4376T 15 20 TOTAL OUTPUT ERROR vs. COMMON-MODE VOLTAGE 1.0 0.8 TOTAL OUTPUT ERROR (%) 5 MAX4376/7/8 toc04 6 TOTAL OUTPUT ERROR (%) 0 SUPPLY VOLTAGE (V) TOTAL OUTPUT ERROR vs. SUPPLY VOLTAGE (VSENSE = 6.25mV) 0.6 0.4 MAX4376H 0.2 0 -0.2 -0.4 -2 -0.6 -3 -0.8 MAX4376F MAX4376T -1.0 -4 5 10 15 20 25 5 10 15 20 25 SUPPLY VOLTAGE (V) COMMON-MODE VOLTAGE (V) GAIN ACCURACY vs. TEMPERATURE TOTAL OUTPUT ERROR vs. TEMPERATURE MAX4376/7/8 toc06 2.0 1.5 1.0 MAX4376H MAX4376F 0.5 0 -0.5 0 30 MAX4376T -1.0 1.0 0.8 TOTAL OUTPUT ERROR (%) 0 GAIN ACCURACY (%) 125 TEMPERATURE (C) SUPPLY VOLTAGE (V) -1 100 MAX4376/7/8 toc05 5 0.6 MAX4376F 0.4 30 MAX4376/7/8 toc07 0 MAX4376T 0.2 0 -0.2 MAX4376H -0.4 -0.6 -1.5 -0.8 -1.0 -2.0 -50 -25 0 25 50 75 TEMPERATURE (C) 4 MAX4376T 0.6 -0.6 0.2 0.55 0.8 MAX4376/7/8 toc03 MAX4376F 1.2 MAX4376/7/8 toc02 0.90 1.2 SUPPLY CURRENT (mA) MAX4376H 0.95 1.4 MAX4376/7/8 toc01 1.00 TOTAL OUTPUT ERROR vs. SUPPLY VOLTAGE (VSENSE = 100mV) TOTAL OUTPUT ERROR (%) SUPPLY CURRENT (PER AMPLIFIER) vs. SUPPLY VOLTAGE SUPPLY CURRENT (mA) MAX4376/MAX4377/MAX4378 Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain 100 125 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (C) _______________________________________________________________________________________ 25 30 Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain MAX4376/7/8 toc08 5 TOTAL OUTPUT ERROR (%) 4 MAX4376 toc09 MAX4376T SMALL-SIGNAL TRANSIENT RESPONSE (VSENSE = 95mV TO 100mV) TOTAL OUTPUT ERROR vs. FULL-SCALE SENSE VOLTAGE CL = 15pF RL =1k IN 5mV/div 3 100mV 95mV 2 MAX4376H MAX4376F 1 2.0V 0 OUT 50mV/div -1 1.9V MAX4376T -2 50 100 VSENSE (mV) 150 200 2s/div MAX4376F SMALL-SIGNAL TRANSIENT RESPONSE (VSENSE = 95mV TO 100mV) MAX4376 toc10 MAX4376H SMALL-SIGNAL TRANSIENT RESPONSE (VSENSE = 95mV to 100mV) CL = 15pF RL = 2.5k IN 5mV/div 100mV 95mV MAX4376 toc11 0 CL = 15pF RL = 5k IN 5mV/div 95mV 5V OUT 100mV/div 100mV 10V OUT 200mV/div 4.75V 9.5V MAX4376T LARGE-SIGNAL TRANSIENT RESPONSE (VSENSE = 6mV to 100mV) MAX4376F LARGE-SIGNAL TRANSIENT RESPONSE (VSENSE = 6mV to 100mV) CL = 15pF RL = 1k IN 45mV/div MAX4376 toc13 2s/div MAX4376 toc12 2s/div CL = 15pF RL = 2.5k 100mV 6mV IN 45mV/div 100mV 6mV 2V 5V OUT 500mV/div OUT 2V/div 0.3V 0.120V 2s/div 2s/div _______________________________________________________________________________________ 5 MAX4376/MAX4377/MAX4378 Typical Operating Characteristics (continued) (VCC = VRS+ = 12V, VSENSE = 100mV, TA = +25C.) Typical Operating Characteristics (continued) (VCC = VRS+ = 12V, VSENSE = 100mV, TA = +25C.) MAX4376H LARGE-SIGNAL TRANSIENT RESPONSE (VSENSE = 6mV to 100mV) CL = 15pF RL = 5k IN 45mV/div 45 MAX4376H 40 100mV 35 6mV 10V GAIN (dB) 30 OUT 3V/div MAX4376/7/8 toc15 SMALL-SIGNAL GAIN vs. FREQUENCY MAX4376 toc14 MAX4376F 25 MAX4376T 20 15 10 0.6V 5 0 1.E+04 2s/div 1.E+05 1.E+06 1.E+07 FREQUENCY (Hz) OUTPUT LOW vs. TEMPERATURE OVERDRIVE RESPONSE AV = +20V/V MAX4376/7/8 toc16 350 750mV IN 200mV/div MAX4376/7/8 toc17 400 300 350mV VOH OUT 2V/div OUTPUT LOW (mV) MAX4376/MAX4377/MAX4378 Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain 250 MAX4376T 200 MAX4376F 150 100 7V MAX4376H 50 0 TIME (500ns) -50 -25 0 25 50 75 TEMPERATURE (C) 6 _______________________________________________________________________________________ 100 125 Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain PIN MAX4376 SOT23-5 MAX4376 MAX4377 MAX4378 SO-8 MAX-8/ SO-8 SO-14/ TSSOP-14 NAME FUNCTION Output Voltage. VOUT_ is proportional to the magnitude of the sense voltage (VRS+ - VRS-). VOUT_ is approximately zero when VRS - > VRS - + (no phase reversal). 1 4 1, 7 1, 7, 8, 14 OUT, OUT_ 2 3 4 11 GND Ground 3 1 8 4 VCC Supply Voltage 4 8 3, 5 3, 5, 10, 12 RS+, RS_+ Power connection to the external sense resistor 5 6 2, 6 2, 6, 9, 13 RS-, RS_- Load-side connection to the external sense resistor -- 2, 5, 7 -- -- Detailed Description The MAX4376/MAX4377/MAX4378 high-side currentsense amplifiers feature a 0 to +28V input common-mode range that is independent of supply voltage. This feature allows the monitoring of current out of a battery in deep discharge and also enables high-side current sensing at voltages greater than the supply voltage (VCC). The MAX4376/MAX4377/MAX4378 operate as follows: current from the source flows through RSENSE to the load (Figure 1). Since the internal sense amplifier's inverting input has high impedance, negligible current flows through RG2 (neglecting the input bias current). Therefore, the sense amplifier's inverting-input voltage equals VSOURCE - (ILOAD)(RSENSE). The amplifier's open-loop gain forces its noninverting input to the same voltage as the inverting input. Therefore, the drop across RG1 equals (I LOAD ) (R SENSE ). Since I RG1 flows through RG1, I RG1 = (ILOAD)(RSENSE)/RG1. The internal current mirror multiplies IRG1 by a current gain factor, , to give IRGD = x I RG1 . Solving I RGD = x (I LOAD )(R SENSE )/RG1. Therefore: VOUT = x (RGD/RG1)(RSENSE x ILOAD) x amp gain where amp gain is 2, 5, or 10. The part's gain equals ( x RGD / RG1) x amp gain. N.C. No Connection. Not internally connected. Set the full-scale output range by selecting RSENSE and the appropriate gain version of the MAX4376/ MAX4377/MAX4378. Applications Information Recommended Component Values The MAX4376/MAX4377/MAX4378 sense a wide variety of currents with different sense resistor values. Table 1 lists common resistor values for typical operation of the MAX4376/MAX4377/MAX4378. Choosing RSENSE To measure lower currents more accurately, use a high value for RSENSE. The high value develops a higher sense voltage that reduces offset voltage errors of the internal op amp. In applications monitoring very high currents, RSENSE must be able to dissipate the I2R losses. If the resistor's rated power dissipation is exceeded, its value may drift or it may fail altogether, causing a differential voltage across the terminals in excess of the absolute maximum ratings. If ISENSE has a large high-frequency component, minimize the inductance of RSENSE. Wire-wound resistors have the highest inductance, metal-film resistors are somewhat better, and low-inductance metal-film resistors are best suited for these applications. Bidirectional Current-Sense Amplifier Therefore: VOUT = (GAIN)(RSENSE)(ILOAD) where GAIN = 20 for MAX437_T. GAIN = 50 for MAX437_F. GAIN = 100 for MAX437_H. Systems such as laptop computers and other devices that have internal charge circuitry require a precise bidirectional current-sense amplifier to monitor accurately the battery's current regardless of polarity. Figure 2 shows the MAX4377 used as a bidirectional current _______________________________________________________________________________________ 7 MAX4376/MAX4377/MAX4378 Pin Description MAX4376/MAX4377/MAX4378 Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain Table 1. Recommended Component Values FULL-SCALE LOAD CURRENT, ILOAD (A) CURRENT-SENSE RESISTOR, RSENSE (m) GAIN (+V/V) FULL-SCALE OUTPUT VOLTAGE (FULL-SCALE VSENSE = 100mV), VOUT (V) 0.1 1000 20 2.0 1 100 5 20 10 10 RSENSE VSOURCE 5.0 10.0 20 2.0 50 5.0 100 10.0 20 2.0 50 5.0 100 10.0 20 2.0 50 100 5.0 10.0 ILOAD TO LOAD BATTERY RSENSE 0 TO +28V RS+ RG1 VCC BATTERY RS- IRG1 +3V TO +28V 50 100 RG2 +3V TO +28V MAX4376 SYSTEM AND CHARGER VCC RS1+ A1 OUT1 RS1- OUT CURRENT MIRROR IRGD VOUT MAX4377 AV = 2, 5, OR 10 OUT RS2- RGD OUT2 GND RS2+ Figure 1. Functional Diagram monitor. This is useful for implementing either smart battery packs or fuel gauges. Current Source Circuit Figure 2. Bidirectional Current Monitor Figure 3 shows a block diagram using the MAX4376 with a switching regulator to make a current source. 8 _______________________________________________________________________________________ Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain VIN MAX1745 LOW-COST SWITCHING REGULATOR 0 TO +18V PROCESS: BiCMOS RSENSE +3V TO +28V RS+ VCC RS- 0.1F MAX4376 LOAD/ BATTERY OUT GND Figure 3. Current Source Pin Configurations (continued) TOP VIEW + + VCC 1 8 RS+ OUT1 1 7 N.C. RS1- 2 3 6 RS- RS1+ OUT 4 5 N.C. GND N.C. 2 GND MAX4376 + 8 VCC OUT1 1 7 OUT2 RS1- 2 3 6 RS2- RS1+ 4 5 RS2+ MAX4377 MAX/SO SO 14 OUT4 MAX4378 13 RS4- 3 12 RS4+ VCC 4 11 GND RS2+ 5 10 RS3+ RS2- 6 9 RS3- 7 8 OUT3 OUT2 SO/TSSOP Ordering Information (continued) GAIN (+V/V) TEMP RANGE MAX4377 T AUA+ 20 -40C to +125C 8 MAX -- MAX4377FAUA+ 50 -40C to +125C 8 MAX -- MAX4377HAUA+ 100 -40C to +125C 8 MAX -- MAX4377TASA+ 20 -40C to +125C 8 SO -- MAX4377FASA+ 50 -40C to +125C 8 SO -- MAX4377HASA+ 100 -40C to +125C 8 SO -- MAX4378 T AUD+ 20 -40C to +125C 14 TSSOP -- MAX4378FAUD+ 50 -40C to +125C 14 TSSOP -- MAX4378HAUD+ 100 -40C to +125C 14 TSSOP -- MAX4378TASD+ 20 -40C to +125C 14 SO -- PART PINPACKAGE TOP MARK MAX4378FASD+ 50 -40C to +125C 14 SO -- MAX4378HASD+ 100 -40C to +125C 14 SO -- Typical Operating Circuit ILOAD VSENSE 0 TO +28V RSENSE +3V TO +28V RS+ VCC RS- 0.1F MAX4376T/F/H A/D CONVERTER LOAD/ BATTERY OUT GND +Denotes a lead(Pb)-free/RoHS-compliant package. _______________________________________________________________________________________ 9 MAX4376/MAX4377/MAX4378 Chip Information ILOAD VSENSE MAX4376/MAX4377/MAX4378 Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. 10 PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 5 SOT U5+1 21-0057 90-0174 8 SOIC S8+2 21-0041 90-0096 8 MAX U8+1 21-0036 90-0092 14 SOIC S14+1 21-0041 90-0096 14 TSSOP U14+1 21-0066 90-0117 ______________________________________________________________________________________ Single/Dual/Quad, High-Side Current-Sense Amplifiers with Internal Gain REVISION NUMBER REVISION DATE 4 4/09 Added automotive part number and lead-free designations 5 6/10 Clarified 0V to 2V is not a high-accuracy range for the device, added soldering temperature and Package Information section 6 2/11 Specified VRS+ value DESCRIPTION PAGES CHANGED 1, 9 1, 2, 10 2, 3 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. 11 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX4376/MAX4377/MAX4378 Revision History