Two AA cell instrumentation amplifier for body networks
Analog Devices has introduced a micro-power ‘zero-drift’ instrumentation amplifier whose inputs extend 300mV beyond the supply rails.
Dubbed AD8237, input offset drift is under 0.3µV/ºC, maximum gain error is 0.005%, drift is 0.5ppm/°C, and CMRR (common-mode rejection ratio) is 114dB.
“With a quiescent supply current of just over 100µA, the amplifier is suited for signal conditioning bridge, temperature and other similar sensors used in low-power designs,” said ADI. Target applications include battery-powered healthcare, consumer and precision instrumentation equipment such as infusion pumps, blood pressure monitors, 4-20mA sensors, gaming peripherals and consumer weigh scales.”
A single supply of 1.8-5.5V powers the chip and it comes in a MSOP-8 package.
Gain between 1 and 1,000 is set by the ratio of two external resistors.
Other spec points include: 75µV input offset, 10kHz bandwidth (G=100), 1.5uVp-p input voltage noise, -40 to 125?C operation.
“The AD8237 operates well in a system with a variety of SAR [successive approximation] A/D converters such as the AD7988-1 16bit converter,” said ADI.
There is a video about the AD8237 here.