MAX471 Maxim Integrated Products, MAX471 Datasheet
MAX471
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MAX471 Summary of contents
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... The MAX471 has an internal 35mΩ current-sense resis- tor and measures battery currents up to ±3A. For appli- cations requiring higher current or increased flexibility, the MAX472 functions with external sense and gain-set- ting resistors ...
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... Current into SHDN, GND, OUT, RG1, RG2, V Current into SIGN.................................................+10mA, -50mA Note 1: Due to special packaging considerations, MAX471 (DIP, SO) has a higher power dissipation rating than the MAX472. RS+ and RS- must be soldered to large copper traces to achieve this dissipation rating. 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 ...
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ELECTRICAL CHARACTERISTICS—MAX472 (V = +3V to +36V, RG1 = RG2 = 200Ω PARAMETER SYMBOL Supply Voltage V Supply Current Input Offset Voltage V (Note 2) Input Bias Current I RG1 Input Bias-Current Matching OUT Current Accuracy I RG ...
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... Precision, High-Side Current-Sense Amplifiers __________________________________________Typical Operating Characteristics (Typical Operating Circuit (MAX471) or circuit of Figure 4, RG1 = RG2 = 200Ω, R otherwise noted.) SUPPLY CURRENT vs. SUPPLY VOLTAGE +85° +25° -40° (V) RS+ MAX471 NO-LOAD OFFSET CURRENT vs. SUPPLY VOLTAGE 2.4 VS+ = VS- 2 -40°C A 2.0 1.8 1 +85° ...
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... Operating Characteristics (continued) (Typical Operating Circuit (MAX471) or circuit of Figure 4, RG1 = RG2 = 200Ω, R otherwise noted.) MAX472 ERROR vs. SENSE VOLTAGE RG1 RG2 RG2 RG1 -15 -25 0 (mV) SENSE MAX471 0mA to 100mA TRANSIENT RESPONSE 0A 100 s/div V = 10V 1%, SIGN PULL-UP = 50k 1% CC OUT MAX471 ...
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... Gain Resistor. Connect to battery side of current-sense resistor through the gain resistor GND Ground or Battery Negative Terminal An open-collector logic output. For the MAX471, a low level indicates current is flowing from 5 5 SIGN RS- to RS+. For the MAX472, a low level indicates a negative V high impedance when SHDN is high. Leave open if SIGN is not needed. ...
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... RS+ Q1 MAX471 Figure 1. MAX471 Functional Diagram POWER SOURCE OR BATTERY Q1 MAX472 Figure 2. MAX472 Functional Diagram _______________________________________________________________________________________ Precision, High-Side Current-Sense Amplifiers R SENSE RG1 A1 R SENSE V SENSE RG1 RG2 RS- RG2 OUT 5 COMP SIGN TO LOAD/CHARGER OUT 5 COMP SIGN 7 ...
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... Since OUT delivers a current, an external voltage gain- setting resistor (R pin in order to get a voltage. R MAX471. RG1 and RG2 are factory trimmed for an out- put current ratio (output current to load current) of 500µA/A. Since they are manufactured of the same material and in very close proximity on the chip, they provide a high degree of temperature stability ...
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... The general circuit of Figure 4 is useful in a wide variety of applications. It can be used for high-current applica- tions (greater than 3A), and also for those where the full- scale load current is less than the 3A of the MAX471. Table 1. Suggested Component Values for the MAX472 CURRENT- ...
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Precision, High-Side Current-Sense Amplifiers In Figure 6, assume the load current to be measured is 10A and that you have determined a 0.3 inch wide, 2 ounce copper to be appropriate. The resistivity of 0.1 inch wide, 2 ounce copper ...
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... IR drops in the paralleled connection. This is necessary to achieve equal current sharing. Power-Supply Bypassing and Grounding The MAX471 has been designed as a “high side” (posi- tive terminal) current monitor to ease the task of grounding any battery charger, thermistor, etc. that may be a part of the battery pack. Grounding the MAX471 requires no special precautions ...
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... 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. 12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 1996 Maxim Integrated Products ...