19-5021; Rev 1; 2/10 KIT ATION EVALU E L B AVAILA 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier The MAX9634 high-side current-sense amplifier offers precision accuracy specifications of V OS less than 250µV (max) and gain error less than 0.5% (max). Quiescent supply current is an ultra-low 1µA. The MAX9634 fits in a tiny, 1mm x 1mm UCSP™ package size or a 5-pin SOT23 package, making the part ideal for applications in notebook computers, cell phones, PDAs, and all battery-operated portable devices where accuracy, low quiescent current, and small size are critical. The MAX9634 features an input common-mode voltage range from 1.6V to 28V. These current-sense amplifiers have a voltage output and are offered in four gain versions: 25V/V (MAX9634T), 50V/V (MAX9634F), 100V/V (MAX9634H), and 200V/V (MAX9634W). The four gain selections offer flexibility in the choice of the external current-sense resistor. The very low 250µV (max) input offset voltage allows small 25mV to 50mV full-scale VSENSE voltage for very low voltage drop at full-current measurement. The MAX9634 is offered in tiny 4-bump UCSP (1mm x 1mm x 0.6mm footprint) and 5-pin SOT23 packages specified for operation over the -40°C to +85°C extended temperature range. Applications Cell Phones PDAs Power-Management Systems Features o Ultra-Low Supply Current of 1µA (max) o Low 250µV (max) Input Offset Voltage o Low < 0.5% (max) Gain Error o Input Common Mode: +1.6V to +28V o Voltage Output o Four Gain Versions Available 25V/V (MAX9634T) 50V/V (MAX9634F) 100V/V (MAX9634H) 200V/V (MAX9634W) o Tiny 1mm x 1mm x 0.6mm, 4-Bump UCSP or 5-Pin SOT23 Packages Ordering Information PART PINPACKAGE GAIN (V/V) TOP MARK MAX9634TERS+ 4 UCSP 25 +ABX MAX9634FERS+ 4 UCSP 50 +ABY MAX9634HERS+ 4 UCSP 100 +ABZ MAX9634WERS+ 4 UCSP 200 +ACA MAX9634TEUK+ 5 SOT23 25 +AFHG MAX9634FEUK+ 5 SOT23 50 +AFHH MAX9634HEUK+ 5 SOT23 100 +AFHI MAX9634WEUK+ 5 SOT23 200 +AFHJ +Denotes a lead(Pb)-free/RoHS-compliant package. Note: All devices are specified over the -40°C to +85°C extended temperature range. Portable/Battery-Powered Systems Notebook Computers UCSP is a trademark of Maxim Integrated Products, Inc. Pin Configurations TOP VIEW (BUMPS ON BOTTOM) RS+ A1 A2 RS+ 5 RS- MAX9634T/F/H/W MAX9634T/F/H/W GND B1 B2 UCSP DRAWINGS NOT TO SCALE RS4 OUT 1 GND 2 GND 3 OUT SOT23 ________________________________________________________________ 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 MAX9634 General Description MAX9634 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier ABSOLUTE MAXIMUM RATINGS RS+, RS- to GND....................................................-0.3V to +30V OUT to GND .............................................................-0.3V to +6V RS+ to RS- ...........................................................................±30V Short-Circuit Duration: OUT to GND ..........................Continuous Continuous Input Current (any pin) ..................................±20mA Continuous Power Dissipation (TA = +70°C) 4-Bump UCSP (derate 3.0mW/°C above +70°C).........238mW 5-Pin SOT23 (derate 3.9mW/°C above +70°C)............312mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range ............................-65°C to +150°C Bump Temperature (soldering) Reflow............................+260°C Lead Temperature (soldering, 10s) .................................+300°C Soldering Temperature (reflow) .......................................+260°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+ = VRS- = 3.6V, VSENSE = (VRS+ - VRS-) = 0V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN VRS+ = 5V, TA = +25°C Supply Current (Note 2) ICC Common-Mode Input Range VCM TYP MAX 0.5 0.85 VRS+ = 5V, -40°C < TA < +85°C 1.1 VRS+ = 28V, TA = +25°C 1.1 VRS+ = 28V, -40°C < TA < +85°C Common-Mode Rejection Ratio CMRR Input Offset Voltage (Note 3) 1.6 1.6V < VRS+ < 28V, -40°C < TA < +85°C 94 VOS MAX9634W TA = +25°C 28 130 100 -40°C < TA < +85°C TA = +25°C 100 Gain Error (Note 4) 50 MAX9634H MAX9634W 100 200 ±0.1 GE MAX9634W Output Resistance (Note 5) OUT Low Voltage 2 ROUT VOL µV 250 25 MAX9634F MAX9634T/MAX9634F/ MAX9634H dB 425 MAX9634T G V 250 300 -40°C < TA < +85°C Gain µA 2.5 Guaranteed by CMRR, -40°C < TA < +85°C MAX9634T/MAX9634F/ MAX9634H 1.8 UNITS TA = +25°C -40°C < TA < +85°C ±0.5 ±0.6 TA = +25°C ±0.1 -40°C < TA < +85°C MAX9634T/MAX9634F/MAX9634H MAX9634W V/V ±0.7 % ±0.8 7.0 14.0 10 20 13.2 26.4 Gain = 25 1.5 7.5 Gain = 50 Gain = 100 Gain = 200 3 6 12 15 30 85 _______________________________________________________________________________________ kΩ mV 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier (VRS+ = VRS- = 3.6V, VSENSE = (VRS+ - VRS-) = 0V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL OUT High Voltage TYP MAX UNITS VOH = VRS- - VOUT (Note 6) 0.1 0.2 V VSENSE = 50mV, gain = 25 125 VSENSE = 50mV, gain = 50 60 VSENSE = 50mV, gain = 100 30 VSENSE = 50mV, gain = 200 15 tS 1% final value, VSENSE = 50mV 100 µs tON 1% final value, VSENSE = 50mV 200 µs VOH Small-Signal Bandwidth (Note 5) BW Output Settling Time Power-Up Time CONDITIONS MIN kHz All devices are 100% production tested at TA = +25°C. All temperature limits are guaranteed by design. VOUT = 0. ICC is the total current into RS+ plus RS- pins. VOS is extrapolated from measurements for the gain-error test. Gain error is calculated by applying two values of VSENSE and calculating the error of the slope vs. the ideal: Gain = 25, VSENSE is 20mV and 120mV. Gain = 50, VSENSE is 10mV and 60mV. Gain = 100, VSENSE is 5mV and 30mV. Gain = 200, VSENSE is 2.5mV and 15mV. Note 5: The device is stable for any external capacitance value. Note 6: VOH is the voltage from VRS- to VOUT with VSENSE = 3.6V/gain. Note 1: Note 2: Note 3: Note 4: Typical Operating Characteristics (VRS+ = VRS- = 3.6V, TA = +25°C, unless otherwise noted.) 20 N (%) N (%) 20 15 15 10 10 5 5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 INPUT OFFSET VOLTAGE (mV) 0.3 0.4 28V 1.0 0.8 3.6V 0.6 0.4 1.8V 0.2 0 0 1.2 MAX9634 toc03 25 SUPPLY CURRENT (µA) 25 1.4 MAX9634 toc02 30 MAX9634 toc01 30 SUPPLY CURRENT vs. TEMPERATURE GAIN ERROR HISTOGRAM INPUT OFFSET VOLTAGE HISTOGRAM 0 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 GAIN ERROR (%) 0.3 0.4 -40 -15 10 35 60 85 TEMPERATURE (°C) _______________________________________________________________________________________ 3 MAX9634 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (VRS+ = VRS- = 3.6V, TA = +25°C, unless otherwise noted.) -45 -50 30 20 5 10 15 20 25 30 0.6 0.4 0 -40 -15 10 35 60 0 85 5 10 15 20 25 TEMPERATURE (°C) COMMON-MODE VOLTAGE (V) GAIN ERROR vs. COMMON-MODE VOLTAGE GAIN ERROR vs. TEMPERATURE VOUT vs. VSENSE (SUPPLY = 3.6V) -0.3 -0.4 3.0 0.05 2.5 G = 100 VOUT (V) -0.2 3.5 0.06 0.04 1.5 0.02 1.0 0.01 0.5 10 15 20 25 -15 10 35 60 85 50 VSENSE (mV) VOUT vs. VSENSE (SUPPLY = 1.6V) SMALL-SIGNAL GAIN vs. FREQUENCY CMRR vs. FREQUENCY 0 GAIN (dB) G = 100 1.0 G = 50 AV = 50V/V -10 -15 -25 60 VSENSE (mV) 80 100 G = 100 -140 -160 -30 40 -80 -120 0.4 0 G = 50 -60 -100 -20 0.2 G = 25 -40 G = 25 0.6 -20 AV = 100V/V -5 1.2 0 GAIN (dB) 1.4 AV = 25V/V MAX9634 toc12 MAX9634 toc10 5 150 100 TEMPERATURE (°C) 1.6 20 0 VOLTAGE (V) 1.8 0.8 G = 25 0 -40 30 MAX9634 toc11 5 G = 50 2.0 0.03 0 -0.5 30 MAX9634 toc09 0.07 GAIN ERROR (%) -0.1 4.0 MAX9634 toc08 0.08 MAX9634 toc07 0 0 0.8 COMMON-MODE VOLTAGE (V) 0.1 0 1.0 0.2 0 0 GAIN ERROR (%) 40 10 -55 4 1.2 SUPPLY CURRENT (µA) -40 1.4 MAX9634 toc05 50 INPUT OFFSET (µV) -35 INPUT OFFSET (µV) 60 MAX9634 toc04 -30 SUPPLY CURRENT vs. COMMON-MODE VOLTAGE INPUT OFFSET vs. TEMPERATURE MAX9634 toc06 INPUT OFFSET vs. COMMON-MODE VOLTAGE VOUT (V) MAX9634 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier 1 10 100 1k 10k FREQUENCY (Hz) 100k 1M 1 10 100 1k 10k FREQUENCY (Hz) _______________________________________________________________________________________ 100k 1M 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier SMALL-SIGNAL PULSE RESPONSE (GAIN = 100) SMALL-SIGNAL PULSE RESPONSE (GAIN = 50) MAX9634 toc13a SMALL-SIGNAL PULSE RESPONSE (GAIN = 25) MAX9634 toc13b 15mV MAX9634 toc13c 30mV 60mV VSENSE 10mV VSENSE 20mV VSENSE 40mV 1.5V 1.5V 1.5V VOUT VOUT 1V VOUT 1V 1V 20µs/div 25µs/div 25µs/div LARGE-SIGNAL PULSE RESPONSE (GAIN = 100) LARGE-SIGNAL PULSE RESPONSE (GAIN = 50) LARGE-SIGNAL PULSE RESPONSE (GAIN = 25) MAX9634 toc14a MAX9634 toc14c MAX9634 toc14b 30mV VSENSE 120mV 60mV VSENSE 10mV 10mV VSENSE 20mV 3V 3V 3V VOUT VOUT VOUT 0.5V 1V 0.5V 20µs/div 25µs/div 25µs/div Pin Description PIN UCSP SOT23 A1 5 NAME FUNCTION RS+ External Sense Resistor Power-Side Connection External Sense Resistor Load-Side Connection A2 4 RS- B1 1, 2 GND Ground B2 3 OUT Output Voltage. VOUT is proportional to VSENSE = VRS+ - VRS-. _______________________________________________________________________________________ 5 MAX9634 Typical Operating Characteristics (continued) (VRS+ = VRS- = 3.6V, TA = +25°C, unless otherwise noted.) 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier MAX9634 Typical Operating Circuit ILOAD RSENSE VBATT = 1.6V TO 28V RS+ RS- R1 R1 VDD = 3.3V LOAD µC P MAX9634 ROUT OUT ADC 10kΩ GND Detailed Description The MAX9634 unidirectional high-side, current-sense amplifier features a 1.6V to 28V input common-mode range. This feature allows the monitoring of current out of a battery with a voltage as low as 1.6V. The MAX9634 monitors current through a current-sense resistor and amplifies the voltage across that resistor. The MAX9634 is a unidirectional current-sense amplifier that has a well-established history. An op amp is used to force the current through an internal gain resistor at RS+, which has a value of R1, such that its voltage drop equals the voltage drop across an external sense resistor, RSENSE. There is an internal resistor at RS- with the Table 1. Internal Gain-Setting Resistors (Typical Values) 6 GAIN (V/V) R1 (Ω) ROUT (kΩ) 200 100 20 100 100 10 50 200 10 25 400 10 same value as R1 to minimize offset voltage. The current through R1 is sourced by a high-voltage p-channel FET. Its source current is the same as its drain current, which flows through a second gain resistor, ROUT. This produces an output voltage, VOUT, whose magnitude is I LOAD x R SENSE x R OUT /R 1 . The gain accuracy is based on the matching of the two gain resistors R1 and R OUT (see Table 1). Total gain = 25V/V for the MAX9634T, 50V/V for the MAX9634F, 100V/V for the MAX9634H, and 200V/V for the MAX9634W. The output is protected from input overdrive by use of an output current-limiting circuit of 7mA (typical) and a 6V clamp protection circuit. Applications Information Choosing the Sense Resistor Choose RSENSE based on the following criteria: Voltage Loss A high RSENSE value causes the power-source voltage to drop due to IR loss. For minimal voltage loss, use the lowest RSENSE value. _______________________________________________________________________________________ 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier VOUT (max) = VRS+ (min) - VSENSE (max) - VOH and: RSENSE = VOUT (max) G × ILOAD (max) VSENSE full scale should be less than VOUT/GAIN at the minimum RS+ voltage. For best performance with a 3.6V supply voltage, select RSENSE to provide approximately 120mV (gain of 25V/V), 60mV (gain of 50V/V), 30mV (gain of 100V/V), or 15mV (gain of 200V/V) of sense voltage for the full-scale current in each application. These can be increased by use of a higher minimum input voltage. Accuracy In the linear region (VOUT < VOUT (max)), there are two components to accuracy: input offset voltage (VOS) and gain error (GE). For the MAX9634, VOS = 250µV (max) and gain error is 0.5% (max). Use the linear equation: Efficiency and Power Dissipation At high current levels, the I2R losses in RSENSE can be significant. Take this into consideration when choosing the resistor value and its power dissipation (wattage) rating. Also, the sense resistor’s value might drift if it is allowed to heat up excessively. The precision VOS of the MAX9634 allows the use of small sense resistors to reduce power dissipation and reduce hot spots. Kelvin Connections Because of the high currents that flow through RSENSE, take care to eliminate parasitic trace resistance from causing errors in the sense voltage. Either use a fourterminal current-sense resistor or use Kelvin (force and sense) PCB layout techniques. Optional Output Filter Capacitor When designing a system that uses a sample-and-hold stage in the ADC, the sampling capacitor momentarily loads OUT and causes a drop in the output voltage. If sampling time is very short (less than a microsecond), consider using a ceramic capacitor across OUT and GND to hold VOUT constant during sampling. This also decreases the small-signal bandwidth of the currentsense amplifier and reduces noise at OUT. VOUT = (gain ± GE) x VSENSE ± (gain x VOS) to calculate total error. A high RSENSE value allows lower currents to be measured more accurately because offsets are less significant when the sense voltage is larger. _______________________________________________________________________________________ 7 MAX9634 OUT Swing vs. VRS+ and VSENSE The MAX9634 is unique because the supply voltage is the input common-mode voltage (the average voltage at RS+ and RS-). There is no separate VCC supply voltage pin. Therefore, the OUT voltage swing is limited by the minimum voltage at RS+. MAX9634 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier ILOAD RSENSE TO WALL-CUBE/ CHARGER VBATT = 1.6V TO 28V RS+ RS- RS+ RSLOAD R1 R1 R1 P P MAX9634 ROUT R1 MAX9634 OUT 10kΩ ROUT OUT VDD = 3.3V 10kΩ µC GND GND ADC ADC Figure 1. Bidirectional Application UCSP Applications Information Bidirectional Application Battery-powered systems may require a precise bidirectional current-sense amplifier to accurately monitor the battery’s charge and discharge currents. Measurements of the two separate outputs with respect to GND yields an accurate measure of the charge and discharge currents, respectively (Figure 1). For the latest application details on UCSP construction, dimensions, tape carrier information, PCB techniques, bump-pad layout, and recommended reflow temperature profile, as well as the latest information on reliability testing results, refer to Application Note 1891: WaferLevel Packaging (WLP) and Its Applications. . Chip Information PROCESS: BiCMOS 8 _______________________________________________________________________________________ 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier PACKAGE CODE DOCUMENT NO. 2 x 2 UCSP R41A1+1 21-0242 5 SOT23 U5-2 21-0057 2x2 UCSP.EPS PACKAGE TYPE _______________________________________________________________________________________ 9 MAX9634 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. 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 MAX9634 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier 10 ______________________________________________________________________________________ 1µA, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier REVISION NUMBER REVISION DATE 0 10/09 Initial release — 1 2/10 Corrected gain error limits in Electrical Characteristics table 2 DESCRIPTION PAGES CHANGED 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 © 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX9634 Revision History