MAX9928FAUA+T

The low-cost, uni-/bidirectional, high-side, current-sense amplifiers are ideal for monitoring battery charge and discharge currents in notebooks, cell phones, and other portable equipment. These devices feature a wide -0.1V to +28V input common-mode voltage range, low 20μA supply current with VOS less than 0.4mV, and a gain accuracy better than 1.0%. The input common-mode range is independent of the supply voltage, ensuring that the current-sense information remains accurate even when the measurement rail is shorted to ground. The MAX9928F features a current output with a transconductance ratio of 5μA/mV. An external resistor converts the output current to a voltage, allowing adjustable gain so that the input sense voltage can be matched to the maximum ADC input swing. The MAX9929F has a voltage output and integrates a 10kΩ output resistor for a fixed voltage gain of 50V/V. A digital SIGN output indicates direction of current flow, so the user can utilize the full ADC input range for measuring both charging and discharging currents. The amplifiers are fully specified over the -40°C to +125°C automotive temperature range, and available in 6-bump UCSP (1mm×1.5mm) and 8-pin μMAX packages. The UCSP package is bump-to-bump compatible with the MAX4372_EBT.

Applications

• Monitoring Charge/Discharge Currents in Portable/Battery-Powered Systems
• Notebook Computers
• General-System/Board-Level Current Monitoring
• Smart-Battery Packs/Chargers
• Precision Current Sources
• Smart Cell Phones
• Super Capacitor Charge/Discharge

Key features

• Wide -0.1V to +28V Common-Mode Range, Independent of Supply Voltage
• 2.5V to 5.5V Operating Supply Voltage
• 20μA Quiescent Supply Current
• 0.4mV (max) Input Offset Voltage
• Gain Accuracy Better than 1% (max)
• SIGN Output Indicates Current Polarity
• Transconductance and Gain Versions Available: 5μA/mV (MAX9928F), 50V/V (MAX9929F)
• Pin Compatible with the MAX4372 in UCSP
• Available in Ultra-Small, 3×2 UCSP (1mm×1.5mm) and 8-Pin μMAX Packages