19-1548; Rev 4; 7/09 Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output The MAX4372 low-cost, precision, high-side currentsense amplifier is available in a tiny, space-saving SOT23-5-pin package. Offered in three gain versions (T = 20V/V, F = 50V/V, and H = 100V/V), this device operates from a single 2.7V to 28V supply and consumes only 30µA. It features a voltage output that eliminates the need for gain-setting resistors and is ideal for today’s notebook computers, cell phones, and other systems where battery/DC current monitoring is critical. 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 2-cell battery pack in deep discharge. The user can set the full-scale current reading by choosing the device (T, F, or H) with the desired voltage gain and selecting the appropriate external sense resistor. This capability offers a high level of integration and flexibility, resulting in a simple and compact current-sense solution. For higher bandwidth applications, refer to the MAX4173T/F/H data sheet. Features o Low-Cost, Compact Current-Sense Solution o 30µA Supply Current o 2.7V to 28V Operating Supply o 0.18% Full-Scale Accuracy o 0.3mV Input Offset Voltage o Low 1.5Ω Output Impedance o Three Gain Versions Available 20V/V (MAX4372T) 50V/V (MAX4372F) 100V/V (MAX4372H) o High Accuracy +2V to +28V Common-Mode Range, Functional Down to 0V, Independent of Supply Voltage o Available in a Space-Saving 5-Pin SOT23 Package and 3 x 2 UCSP™ (1mm x 1.5mm) Package Ordering Information Information Ordering PART Applications Power-Management Systems General-System/Board-Level Current Monitoring TEMP RANGE PIN-PACKAGE MAX4372TEUK-T MAX4372TESA MAX4372TEBT-T -40°C to +85°C -40°C to +85°C -40°C to +85°C TOP MARK ADIU — ACX 5 SOT23-5 8 SO 3 x 2 UCSP Note: Gain values are as follows: 20V/V for the T version, 50V/V for the F version, and 100V/V for the H version. Ordering Information continued at end of datasheet. Notebook Computers Portable/Battery-Powered Systems Smart-Battery Packs/Chargers Typical Operating Circuit Cell Phones Precision-Current Sources ILOAD Pin Configurations TOP VIEW 1 GND 1 OUT 2 5 2 3 RSA VCC B RS+ GND OUT RS- MAX4372T/F/H A/D CONVERTER RSENSE OUT VSENSE LOAD/ BATTERY MAX4372T/F/H MAX4372T/F/H VCC GND TOP VIEW (BUMPS ON BOTTOM) 3 4 RS- RS+ UCSP SOT23-5 Pin Configurations continued at end of datasheet. VCC +2.7V TO +28V 0.1μF VCC RS+ VIN 0 TO 28V UCSP is a trademark of Maxim Integrated Products, Inc. ________________________________________________________________ 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. MAX4372T/F/H General Description MAX4372T/F/H Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output ABSOLUTE MAXIMUM RATINGS VCC, RS+, RS- to GND ...........................................-0.3V to +30V OUT to GND ...........................................................-0.3V to +15V Differential Input Voltage (VRS+ - VRS-) ..............................±0.3V Current into Any Pin..........................................................±10mA Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 7.1mW/°C above +70°C).............571mW 8-Pin SO (derate 5.88mW/°C above +70°C).................471mW 3 x 2 UCSP (derate 3.4mW/°C above +70°C) ...........273.2mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s). ................................+300°C Bump Temperature (soldering) Infrared (15s) ................................................................+200°C Vapor Phase (20s) ........................................................+215°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 (VRS+ = 0 to 28V, VCC = 2.7V to 28V, VSENSE = 0, RLOAD = 1MΩ, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Operating Voltage Range (Note 2) SYMBOL CONDITIONS MIN TYP MAX UNITS VCC 2.7 28 V Common-Mode Input Range (Note 3) VCMR 0 28 V Common-Mode Rejection CMR Supply Current Leakage Current ICC IRS+, IRSIRS+ Input Bias Current IRSFull-Scale Sense Voltage (Note 4) Input Offset Voltage (Note 5) VSENSE VOS Full-Scale Accuracy (Note 5) VRS+ > 2V 85 VRS+ > 2V, VSENSE = 5mV 30 60 µA 0.05 1.2 µA VCC = 0 VRS+ > 2V 0 1 VRS+ ≤ 2V -25 2 VRS+ > 2V 0 2 VRS+ ≤ 2V -50 150 Gain = 100V/V 100 OUT High Voltage MAX4372_ESA 0.3 ±0.8 MAX4372_EUK, _EBT 0.3 ±1.3 TA = TMIN to TMAX VCC = VRS+ = 12V MAX4372_ESA ±1.1 MAX4372_EUK, _EBT ±1.9 ±0.18 2 ±3 ±0.15 ±7 VSENSE = 100mV, VCC = 12V, VRS+ = 0.1V (Note 7) ±1 ±28 VSENSE = 6.25mV, VCC = 12V, VRS+ = 12V (Note 8) ±0.15 % % IOUT = 10µA 2.6 IOUT = 100µA 9 65 0.1 0.25 VCC = 2.7V, IOUT = -500µA mV ±6 VSENSE = 100mV, VCC = 28V, VRS+ = 28V (Note 7) VCC = 2.7V VCC - VOH mV TA = +25°C VCC = VRS+ = 12V VSENSE = 100mV, VCC = 12V, VRS+ = 12V (Note 7) OUT Low Voltage µA 2 Gain = 20V/V or 50V/V VSENSE = 100mV, VCC = 12V, VRS+ = 12V, TA = +25°C (Note 7) Total OUT Voltage Error (Note 6) dB _______________________________________________________________________________________ mV V Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output (VRS+ = 0 to 28V, VCC = 2.7V to 28V, VSENSE = 0, RLOAD = 1MΩ, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER -3dB Bandwidth SYMBOL BW Gain CONDITIONS VRS+ = 12V, VCC = 12V, CLOAD = 10pF MIN TYP VSENSE = 20mV, gain = 20V/V 275 VSENSE = 20mV, gain = 50V/V 200 VSENSE = 20mV, gain = 100V/V 110 VSENSE = 6.25mV 50 MAX4372T 20 MAX4372F 50 MAX4372H UNITS kHz V/V 100 Gain Accuracy VSENSE = 20mV to 100mV TA = +25°C Gain = 20V/V, VCC = 12V, VRS+ = 12V, CLOAD = 10pF VSENSE = 6.25mV to 100mV 20 OUT Settling Time to 1% of Final Value VSENSE = 100mV to 6.25mV 20 Capacitive-Load Stability MAX ±0.25 TA = -40°C to +85°C ±2.5 ±5.5 % µs No sustained oscillations OUT Output Resistance ROUT VSENSE = 100mV Power-Supply Rejection PSR VOUT = 2V, VRS+ > 2V 75 1000 pF 1.5 Ω 85 dB Power-Up Time to 1% of Final Value VCC = 12V, VRS+ = 12V, VSENSE = 100mV, CLOAD = 10pF 0.5 ms Saturation Recovery Time (Note 9) VCC = 12V, VRS+ = 12V, CLOAD = 10pF 0.1 ms Note 1: All devices are 100% production tested at TA = +25°C. All temperature limits are guaranteed by design. Note 2: Guaranteed by PSR test. Note 3: Guaranteed by OUT Voltage Error test. Note 4: Output voltage is internally clamped not to exceed 12V. Note 5: VOS is extrapolated from the gain accuracy tests. Note 6: Total OUT voltage error is the sum of gain and offset voltage errors. Note 7: Measured at IOUT = -500µA (RLOAD = 4kΩ for gain = 20V/V, RLOAD = 10kΩ for gain = 50V/V, RLOAD = 20kΩ for gain = 100V/V). Note 8: 6.25mV = 1/16 of 100mV full-scale voltage (C/16). Note 9: The device will not reverse phase when overdriven. _______________________________________________________________________________________ 3 MAX4372T/F/H ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VCC = 12V, VRS+ = 12V, VSENSE = 100mV, TA = +25°C, unless otherwise noted.) AV = +100V/V AV = +50V/V 30.0 35 AV = +20V/V 30 AV = +100V/V 31.5 SUPPLY CURRENT (μA) 32.5 32.0 MAX4372T toc02 MAX4372 toc01 40 SUPPLY CURRENT (μA) 25 20 15 8 12 16 20 24 -15 28.0 10 35 60 85 4 8 12 16 20 24 POWER-SUPPLY REJECTION vs. FREQUENCY 1.0 -0.4 -0.6 -45 -50 -55 AV = +100V/V 0.5 PSR (dB) G = +50V/V G = +20V/V -40 28 MAX4372T toc06 1.5 -0.8 AV = +50V/V AV = +20V/V 0 -60 -65 -70 -75 -80 -0.5 -1.0 -85 10 15 20 25 -90 -1.0 30 0 50 1.4 0.8 G = +50V/V G = +100V/V 0.4 G = +20V/V 10 15 20 300 100 1k -0.2 25 COMMON-MODE VOLTAGE (V) 30 AV = +100V/V -0.4 100k TOTAL OUTPUT ERROR vs. TEMPERATURE AV = +50V/V -0.3 10k FREQUENCY (Hz) AV = +20V/V -0.1 GAIN ACCURACY (%) 1.0 5 250 GAIN ACCURACY vs. TEMPERATURE 1.2 0 200 0 MAX4372T toc07 1.6 0.2 150 VSENSE (mV) TOTAL OUTPUT ERROR vs. COMMON-MODE VOLTAGE 0.6 100 -0.5 -0.6 -0.7 1.0 0.8 TOTAL OUTPUT ERROR (%) 5 MAX4372T toc08 0 SUPPLY VOLTAGE (V) 4 VSENSE = 5mV 0 TOTAL OUTPUT ERROR vs. VSENSE OUTPUT ERROR (%) OUTPUT ERROR (%) -40 TOTAL OUTPUT ERROR vs. SUPPLY VOLTAGE -0.2 0 AV = +20V/V COMMON-MODE VOLTAGE (V) 0.4 -1.2 29.5 TEMPERATURE (°C) G = +100V/V 0 AV = +50V/V SUPPLY VOLTAGE (V) 0.6 0.2 28 MAX4372T toc05 4 VSENSE = 5mV 0 MAX4372 toc04 0 30.0 28.5 5 VSENSE = 5mV 25.0 30.5 29.0 10 27.5 31.0 MAX4372T toc09 SUPPLY CURRENT (μA) 35.0 SUPPLY CURRENT vs. COMMON-MODE VOLTAGE SUPPLY CURRENT vs. TEMPERATURE MAX4372 toc03 SUPPLY CURRENT vs. SUPPLY VOLTAGE OUTPUT ERROR (%) MAX4372T/F/H Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output 0.6 0.4 AV = +50V/V 0.2 0 -0.2 -0.4 -0.8 -0.6 -0.9 -0.8 AV = +100V/V AV = +20V/V -1.0 -1.0 -40 -15 10 35 TEMPERATURE (°C) 60 85 -40 -15 10 35 TEMPERATURE (°C) _______________________________________________________________________________________ 60 85 Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output MAX4372T SMALL-SIGNAL TRANSIENT RESPONSE MAX4372F SMALL-SIGNAL TRANSIENT RESPONSE MAX4372H SMALL-SIGNAL TRANSIENT RESPONSE MAX4372T toc10 MAX4372T toc11 MAX4372T toc12 30mV 30mV VSENSE 30mV VSENSE VSENSE 10mV 10mV 600mV VOUT 10mV 3V 1.5V VOUT VOUT 200mV 1V 0.5V 20μs/div 20μs/div 20μs/div MAX4372F LARGE-SIGNAL TRANSIENT RESPONSE MAX4372T LARGE-SIGNAL TRANSIENT RESPONSE MAX4372T toc14 MAX4372T toc13 150mV VSENSE 150mV VSENSE 50mV 50mV 3V 7.5V VOUT VOUT 2.5V 1V 20μs/div 20μs/div MAX4372H LARGE-SIGNAL TRANSIENT RESPONSE SMALL-SIGNAL GAIN vs. FREQUENCY MAX4372T toc15 MAX4372T toc16 3 2 1 100mV VSENSE G = 50V/V 0 10V GAIN (dB) 0 G = 20V/V -1 -2 -3 G = 100V/V -4 VOUT -5 -6 0 -7 -8 20μs/div VSENSE = 20mV 1k 10k 100k 1M FREQUENCY (Hz) _______________________________________________________________________________________ 5 MAX4372T/F/H Typical Operating Characteristics (continued) (VCC = 12V, VRS+ = 12V, VSENSE = 100mV, TA = +25°C, unless otherwise noted.) Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output MAX4372T/F/H Pin Description PIN SOT23 1 SO 3 UCSP A2 2 4 3 4 NAME FUNCTION GND Ground A3 OUT Output Voltage. VOUT is proportional to the magnitude of VSENSE (VRS+ - VRS-). 1 A1 VCC Supply Voltage. Use at least a 0.1µF capacitor to decouple VCC from fast transients. 8 B1 RS+ Power Connection to the External Sense Resistor 5 6 B3 RS- Load-Side Connection to the External Sense Resistor — 2, 5, 7 — N.C. No Connection. Not internally connected. _______________Detailed Description The MAX4372 high-side current-sense amplifier features a 0 to 28V input common-mode range that is independent of supply voltage. This feature allows the monitoring of current flow out of a battery in deep discharge, and also enables high-side current sensing at voltages far in excess of the supply voltage (VCC). Current flows through the sense resistor, generating a sense voltage (Figure 1). Since A1’s inverting input is high impedance, the voltage on the negative terminal equals VIN - VSENSE. A1 forces its positive terminal to match its negative terminal; therefore, the voltage across RG1 (VIN - V1-) equals VSENSE. This creates a current to flow through RG1 equal to VSENSE / RG1. The transistor and current mirror amplify the current by a factor of β. This makes the current flowing out of the current mirror equal to: IM = β VSENSE / RG1 A2’s positive terminal presents high impedance, so this current flows through RGD, with the following result: V2+ = RGD β · VSENSE / RG1 R1 and R2 set the closed-loop gain for A2, which amplifies V2+, yielding: VOUT = RGD · β · VSENSE / RG1 (1 + R2 / R1) The gain of the device equals: VOUT = RGD · β (1 + R2 / R1) / RG1 VSENSE __________Applications Information Recommended Component Values The MAX4372 operates over a wide variety of current ranges with different sense resistors. Table 1 lists common resistor values for typical operation of the MAX4372. 6 VIN 0 TO 28V RG1 100kΩ 2.7V TO 28V V1+ VCC A1 RG2 100kΩ RS+ RSENSE ILOAD V1CURRENT MIRROR RGD IM TO LOAD MAX4372T/F/H OUT VSENSE RS- V2+ A2 V2- R2 R1 GND Figure 1. Functional Diagram Choosing RSENSE Given the gain and maximum load current, select RSENSE such that VOUT does not exceed VCC - 0.25V or 10V. To measure lower currents more accurately, use a high value for RSENSE. A higher value develops a higher sense voltage, which overcomes offset voltage errors of the internal current amplifier. In applications monitoring very high current, ensure RSENSE is able to dissipate its own 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. _______________________________________________________________________________________ Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output FULL-SCALE LOAD CURRENT, ILOAD (A) 0.1 1 5 10 CURRENT-SENSE RESISTOR, RSENSE (mΩ) 1000 100 20 10 Using a PC Board Trace as RSENSE If the cost of RSENSE is an issue and accuracy is not critical, use the alternative solution shown in Figure 2. This solution uses copper PC board traces to create a sense resistor. The resistivity of a 0.1-inch-wide trace of 2-ounce copper is about 30mΩ/ft. The resistance temperature coefficient of copper is fairly high (approximately 0.4%/°C), so systems that experience a wide temperature variance must compensate for this effect. In addition, self-heating will introduce a nonlinearity error. Do not exceed the maximum power dissipation of the copper trace. For example, the MAX4372T (with a maximum load current of 10A and an RSENSE of 5mΩ) creates a full-scale VSENSE of 50mV that yields a maximum VOUT of 1V. RSENSE, in this case, requires about 2 inches of 0.1inch-wide copper trace. GAIN (V/V) FULL-SCALE OUTPUT VOLTAGE (FULL-SCALE VSENSE = 100mV), VOUT (V) 20 2.0 50 5.0 100 10.0 20 2.0 50 5.0 100 10.0 20 2.0 50 5.0 100 10.0 20 2.0 50 5.0 100 10.0 INPUT 0.3in COPPER MAX4372T/F/H Table 1. Recommended Component Values LOAD/BATTERY RSENSE 0.1in COPPER 0.3in COPPER VSENSE RS+ VCC 2.7V TO 28V MAX4372T/F/H RS- OUT GND UCSP Applications Information For the latest application details on UCSP construction, dimensions, tape carrier information, printed circuit board techniques, bump-pad layout, and recommended reflow temperature profile, as well as the latest information on reliability testing results, go to the Maxim's website at www.maxim-ic.com/ucsp to find the Application Note: UCSP—A Wafer-Level Chip-Scale Package. Figure 2. Connections Showing Use of PC Board _______________________________________________________________________________________ 7 Ordering Information (continued) PART TEMP RANGE PIN-PACKAGE MAX4372FEUK-T -40°C to +85°C 5 SOT23-5 MAX4372FESA -40°C to +85°C 8 SO Pin Configurations (continued) TOP MARK ADIV — VCC 1 -40°C to +85°C 3 x 2 UCSP ACY N.C. 2 MAX4372HEUK-T -40°C to +85°C 5 SOT23-5 MAX4372HESA -40°C to +85°C 8 SO MAX4372HEBT-T -40°C to +85°C 3 x 2 UCSP ADIW — ACZ GND MAX4372FEBT-T Chip Information 8 RS+ 7 N.C. 3 6 RS- OUT 4 5 N.C. MAX4372T/F/H SO TRANSISTOR COUNT: 225 PROCESS: BiCMOS 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. 6L, UCSP.EPS MAX4372T/F/H Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output PACKAGE OUTLINE, 3x2 UCSP 21-0097 Note: MAX4372_EBT uses package code B6-2. 8 _______________________________________________________________________________________ G 1 1 Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output N E H INCHES MILLIMETERS MAX MIN 0.053 0.069 0.004 0.010 0.014 0.019 0.007 0.010 0.050 BSC 0.150 0.157 0.228 0.244 0.050 0.016 MAX MIN 1.75 1.35 0.25 0.10 0.49 0.35 0.19 0.25 1.27 BSC 3.80 4.00 5.80 6.20 0.40 SOICN .EPS DIM A A1 B C e E H L 1.27 VARIATIONS: 1 INCHES TOP VIEW DIM D D D MIN 0.189 0.337 0.386 MAX 0.197 0.344 0.394 MILLIMETERS MIN 4.80 8.55 9.80 MAX 5.00 8.75 10.00 N MS012 8 AA 14 AB 16 AC D A B e FRONT VIEW A1 C 0∞-8∞ L SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, .150" SOIC APPROVAL DOCUMENT CONTROL NO. 21-0041 REV. B 1 1 _______________________________________________________________________________________ 9 MAX4372T/F/H Package Information (continued) 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. Package Information (continued) 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. SOT-23 5L .EPS MAX4372T/F/H Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output 10 ______________________________________________________________________________________ Low-Cost, UCSP/SOT23, Micropower, High-Side Current-Sense Amplifier with Voltage Output Revision History REVISION NUMBER REVISION DATE 4 7/09 DESCRIPTION Updated feature in accordance with actual performance of the product PAGES CHANGED 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 ____________________ 11 © 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.