Tiny in-amp boosts system-level performance and saves space

For space-constrained industrial and instrumentation applications that demand precise measurement and high channel densities, the AD8222 offers designers twice the number of output channels and 40 dB higher common mode rejection ratio (CMRR) than competitive dual-channel in-amps, all in a package that is 50% smaller. The AD8222’s combination of higher channel count, smaller size and superior noise rejection enables manufacturers of factory automation systems, medical monitoring devices and other industrial and instrumentation equipment to significantly boost the precision, accuracy, channel density and response time of their products without increasing component count or board size.

The new device can also be configured as a differential output instrumentation amplifier. This differential output capability, coupled with the AD8222’s outstanding noise performance (8 nV/root-Hz input noise) allows designers to use smaller supply rails without sacrificing signal-to-noise performance. The unique ability of the new in-amp to drive differentially also allows systems designers to pair the AD8222 with high-performance differential-input analog-to-digital converters (ADCs) and affords them the flexibility of operating their products with a single supply or with signal conditioning blocks to further improve noise immunity. Additionally, while competing multi-chip in-amp solutions are unable to specify differential performance, the AD8222’s single-chip differential operation is specified for all key performance parameters.

The AD8222 dual-channel in-amp has the highest CMRR in its class, an advantage for designers building multi-channel devices with a low tolerance for noise, such as electrocardiograms (ECGs), electroencephalograms (EEGs) and precision industrial control systems. The AD8222 features 80-dB CMRR up to 10 kHz (G=1). This is 40 dB higher than the nearest competing dual-channel in amp and outperforms single-channel in amps by 6 dB at dc and more than 20 dB out to the full 10 kHz range. The new dual-channel in-amp also offers 2 volts per microsecond slew rate, 8 nV/root-Hz maximum input voltage noise at 1 kHz, 0.25 microvolts p-p input noise and a wide power supply range of ±2.3 V to ±18 V.

The AD8222 dual-channel in-amp is available in a 4 mm x 4 mm 16-lead LFCSP (lead-frame chip-scale package) - the same size as packages used by competing single-output in-amps. The amplifier is well suited for operation with differential input ADCs, including the AD7661, AD7675, AD7680 and AD7940 from Analog Devices. The AD8222 is currently sampling and will be available in volume production in the third quarter. The AD8222 will be priced at $3.59 in 1,000-unit quantities.