The AD8278 and AD8279 are general-purpose difference amplifiers intended for precision signal conditioning in power critical applications that require both high performance and low power. The AD8278 and AD8279 provide exceptional common-mode rejection ratio (80 dB) and high bandwidth while amplifying input signals that are well beyond the supply rails. The on-chip resistors are laser trimmed for excellent gain accuracy and high CMRR. They also have extremely low gain drift vs. temperature.
The common-mode range of the amplifier extends to almost triple the supply voltage (for G = ½), making the amplifer ideal for single-supply applications that require a high common-mode voltage range. The internal resistors and ESD circuitry at the inputs also provide overvoltage protection to the op amp.
The AD8278 and AD8279 can be used as difference amplifiers with G = ½ or G = 2. They can also be connected in a high precision, single-ended configuration for non inverting and inverting gains of −½, −2, +3, +2, +1½, +1, or +½. The AD8278 and AD8279 provide an integrated precision solution that has a smaller size, lower cost, and better performance than a discrete alternative.
The AD8278 and AD8279 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, which is ideal for battery-operated and portable systems. For unity-gain difference amplifiers with similar performance, refer to the AD8276 and AD8277 data sheets.
The AD8278 is available in the space-saving 8-lead MSOP and SOIC packages, and the AD8279 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
* Instrumentation amplifier building block
* Portable, battery-powered equipment
* Test and measurement
### Features and Benefits
Wide input range beyond supplies
Rugged input overvoltage protection
Low supply current: 200 μA maximum (per amplifier)
Low power dissipation:
0.5 mW at VS = 2.5 V
Bandwidth: 1 MHz (G = ½)
CMRR: 80 dB minimum,
dc to 20 kHz (G = ½, B Grade)
Low offset voltage drift: ±1 μV/°C maximum (B Grade)
