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MAX9923：Ultra-Precision, High-Side Current-Sense Amplifiers

Use Autozeroing Front-End to Achieve VOS < 10µV, Allowing Small VSENSE and RSENSE

The MAX9922/MAX9923 ultra-precision, high-side current-sense amplifiers feature ultra-low offset voltage (VOS) of 25µV (max) and laser-trimmed gain accuracy better than 0.5%. The combination of low VOS and high-gain accuracy allows precise current measurements even at very small sense voltages. The MAX9922/MAX9923 are capable of both unidirectional and bidirectional operation. For unidirectional operation, connect REF to GND. For bidirectional operation, connect REF to VDD/2. The MAX9922 has adjustable gain set with two external resistors. The MAX9923T/MAX9923H/MAX9923F use an internal laser-trimmed resistor for fixed gain of 25V/V, 100V/V, and 250V/V, respectively. The devices operate from a +2.85V to +5.5V single supply, independent of the input common-mode voltage, and draw only 700µA operating supply current and less than 1µA in shutdown. The +1.9V to +28V current-sense input common-mode voltage range makes the MAX9922/MAX9923 ideal for current monitoring in applications where high accuracy, large common-mode measurement range, and minimum full-scale VSENSE voltage is critical. The MAX9922/MAX9923 use a spread-spectrum autozeroing technique that constantly measures and cancels the input offset voltage, eliminating drift over time and temperature, and the effect of 1/f noise. This, in conjunction with the indirect current-feedback technique, achieves less than 25µV (max) offset voltage. The MAX9922/MAX9923 are available in a small 10-pin µMAX® package and are specified over the -40°C to +85°C extended temperature range.

Key Features Ultra-Precision VOS Over Temperature MAX9922: ±10µV (max) MAX9923T: ±25µV (max) MAX9923H: ±20µV (max) MAX9923F: ±10µV (max) ±0.5% (max) Full-Scale Gain Accuracy Bidirectional or Unidirectional ISENSE Multiple Gains Available Adjustable (MAX9922) +25V/V (MAX9923T) +100V/V (MAX9923H) +250V/V (MAX9923F) 1.9V to 28V Input Common-Mode Voltage, Independent of VDD Supply Voltage: +2.85V to +5.5V 700µA Supply Current, 1µA Shutdown Current Extended Temperature Range (-40°C to +85°C) Available in Space-Saving 10-Pin µMAX

MAX9922, MAX9923: Typical Operating Circuit Applications/Uses Handheld Li+ Battery Current Monitoring Notebook/Desktop Power Management Precision Current Sources

DataSheet

Parametrics

Design kits & evaluation modules

• MAX9922EVKIT

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