Date: 03/10/2008

Maxim's current-sense amplifiers with wide input common-mode range

Maxim Integrated Products announced the availability of the new current-sense amplifiers, MAX9928/MAX9929, for monitoring charge and discharge currents. These devices use a rail-to-rail input stage to achieve a wide, -0.1V to +28V, input common-mode range.

The wide input common-mode range of these new bi-directional current-sense amplifiers enables them to monitor deeply discharged batteries and super-capacitors. The new architecture employed in this device offers true ground sensing and high-side current sensing in the same chip, which helps to provide this wide input range and allows both unidirectional and bi-directional (charge/discharge) current monitoring capability.

The other features include:

1. Consumes only 20µA of quiescent current
2. +2.5V to +5.5V supply voltage.
3. Have less than 400µV of offset voltage.
4. On-chip, laser-trimmed, gain-setting resistors.
5. MAX9928 is a current-output device and is available in two transconductance gain options: 2µA/mV and 5µA/mV.
6. The user can select the output resistor to convert the current to a voltage to match the input range of an ADC.
7. MAX9929 is a voltage-output device with fixed-gain options of 20V/V and 50V/V.
8. Both chips have a digital sign output to indicate direction of current flow. This allows the user to maximize the output-voltage swing and utilize an ADC's full input range for measuring charge/discharge currents.
9. Operating temperature range: -40°C to +125°C

Packaging: 1mm x 1.5mm, 6-bump UCSP and 8-pin µMAX packages.
Prices start at $0.85 (1000-up, FOB USA).

For more information, go to: http://www.maxim-ic.com