nanoPower, 4-Bump UCSP/SOT23, Precision Current-Sense Amplifier

Industry's Smallest Current-Sense Amp: 1mm x 1mm with ICC < 1µA, VOS < 250µV, Gain Error < 0.5%

Please check latest availability status for a specific part variant.


The MAX9634 high-side current-sense amplifier offers precision accuracy specifications of VOS 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.
MAX9634: Typical Operating Circuit MAX9634: Typical Operating Circuit Enlarge+

Key Features

  • Ultra-Low Supply Current of 1µA (max)
  • Low 250µV (max) Input Offset Voltage
  • Low < 0.5% (max) Gain Error
  • Input Common Mode: +1.6V to +28V
  • Voltage Output
  • Four Gain Versions Available
    • 25V/V (MAX9634T)
    • 50V/V (MAX9634F)
    • 100V/V (MAX9634H)
    • 200V/V (MAX9634W)
  • Tiny 1mm x 1mm x 0.6mm, 4-Bump UCSP or 5-Pin SOT23 Packages


  • Cell Phones
  • Notebook Computers
  • PDAs
  • Portable/Battery-Powered Systems
  • Power-Management Systems

See parametric specs for Current Sense Amplifiers (52)

Part NumberOutput FormatCMVR
Bi-Dir. Curr. SenseVSENSE_FS
VOS @25°C
GainGain Accuracy @25°C
ComparatorsOper. Temp.
minmaxminmaxtyprecomm.maxmax@ -3dBSee Notes
MAX9634 Voltage1.6281.6280.5No
100 V/V
200 V/V
25 V/V
50 V/V
0-40 to +85
UCSP (R)/4
$0.75 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX9634EVKIT: Evaluation Kit for the MAX9634
MAXNANOPWRBD: Evaluation Kit for the MAX32660, MAX11615, MAX40007, MAX9119, MAX9634, MAX17222
Product Reliability Reports: MAX9634.pdf 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >


Related Resources

High-Speed Quad Driver with Integrated DACs, Cable-Droop Compensation, Slew-Rate Control, and VHH Fourth-Level Drive

  • Low Power at High-Speed Maximizes Driver Performance
    • 700mW per Channel
    • 2.57Gbps at +1V Programmed
    • 280ps Typical Rise/Fall Times at +2V (20% to 80%)
  • Integrated Functionality Provides Value-Added Features
    • Programmable Double Time Constant Cable-Droop Compensation
    • Digital Slew-Rate Control for EMI Sensitive Applications
    • Adjustable Output Resistance with 360mΩ Resolution

  • MAX40662
    Quad Transimpedance Amplifier with Input Current Clamp and Multiplexer for LiDAR

    • AEC-Q100
    • Enables ASIL Compliance (FMEDA Available Upon Request)
    • Internal Multiplexer

    Dual 280ps High-Speed Comparator, Ultra-Low Dispersion with LVDS Outputs

    • Fast Propagation Delay: 280ps, Typ
    • Low Overdrive Dispersion: 25ps (VOD = 10mV to 1V)
    • Supply Voltage 2.7V to 3.6V