Low Power, Wide Supply Range, Low Cost Unity-Gain Difference Amplifiers

The AD8276/AD8277 are general-purpose, unity-gain difference amplifiers intended for precision signal conditioning in power critical applications that require both high performance and low power. They provide exceptional 86 dB common-mode rejection ratio (CMRR) and high bandwidth while amplifying signals well beyond the supply rails. The on-chip resistors are laser trimmed for gain drift of 1 ppm/°C and high CMRR. The AD8276/AD8277 also have extremely low gain drift vs. temperature.

The common-mode range of the amplifiers extends to almost double the supply voltage, making these amplifiers ideal for single-supply applications that require a high common-mode voltage range. The internal resistors and electrostatic discharge (ESD) circuitry at the inputs also provide overvoltage protection to the op amps.

The AD8276/AD8277 are unity-gain stable. Although they are optimized for use as difference amplifiers, they can also be connected in high precision, single-ended configurations with G = −1, +1, or +2. The AD8276/AD8277 provide an integrated precision solution that has smaller size, lower cost, and improved performance than a discrete alternative.

The AD8276/AD8277 operate on single supplies (2.0 V to 36 V) or dual supplies (±2 V to ±18 V). The maximum quiescent supply current is 200 μA per channel, which is ideal for battery-operated and portable systems.

The AD8276 is available in the space-saving 8-lead mini small outline package (MSOP) and the standard small outline (SOIC) package, as well as in die form, and the AD8277 is offered in a 14-lead SOIC package. Both are specified for performance over the industrial temperature range of −40°C to +85°C and are fully RoHS compliant.

Applications

* Voltage measurement and monitoring

* Current measurement and monitoring

* Differential output instrumentation amplifier

* Portable, battery-powered equipment

* Test and measurement

* Wide input range beyond supplies

* Rugged input overvoltage protection

* Low supply current: 200 μA maximum per channel

* Low power dissipation: 0.54 mW at VS = 2.7 V

* Bandwidth: 550 kHz

* CMRR: 86 dB minimum, dc to 10 kHz