Current-sense amplifier offers chip-select pin

Maxim Integrated Products has added the MAX9934 to its range of high-side current-sense amplifiers (CSAs). Offered in space-saving UCSP and microMAX packages, the MAX9934 is ideal for notebook computers, MP3 players, smartphones, and other portable electronics that require precision monitoring on multiple supply rails.

This precision CSA utilises a current-output architecture and a chip-select pin to enhance design flexibility and simplify power-management schemes. The current-output architecture allows designers to set the voltage gain using an external resistor (Rout) for greater flexibility. Meanwhile, the inclusion of a chip-select pin enables multiple MAX9934s, monitoring different supplies, to be multiplexed onto one ADC channel with a single Rout. This unique functionality allows designers to implement advanced power-monitoring and power-management schemes when a limited number of analogue read channels are available.

Maxim's autozeroing techniques ensure an input-offset voltage (Vos) of less than ±10microvolts and gain error of less than 0.25%. These precision specifications allow the use of very small sense voltages for minimally invasive current monitoring.

The MAX9934 is fully specified over the -40°C to +125°C automotive temperature range, and is available in 8-pin microMAX and tiny, 1mm x 1.5mm, 6-bump UCSP packages. Prices start at Rs.43.87 ($0.95) (1000-up, FOB USA).