The MAX9928F/MAX9929F 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 MAX9928F/MAX9929F are fully specified over the -40°C to +125°C automotive temperature range, and available in 6-bump UCSP™ (1mm x 1.5mm) and 8-pin µMAX® packages. The UCSP package is bump-to-bump compatible with the MAX4372_EBT.
Applications
- General-System/Board-Level Current Monitoring
- Monitoring Charge/Discharge Currents in Portable/Battery-Powered Systems
- Notebook Computers
- Precision Current Sources
- Smart-Battery Packs/Chargers
- Smart-Cell Phones
- Super Capacitor Charge/Discharge
