High-precision, fully differential programmable gain amplifier

October 15, 2013 // By Graham Prophet
Texas Instruments' PGA281 is a zero-drift PGA providing 5 µV offset voltage for precision and long-term stability.

A fully differential, zero-drift, 36-V programmable gain amplifier, the PGA281 offers the lowest offset voltage in its class to improve accuracy and long-term stability. Its zero-drift architecture enables DC precision and long-term stability. It also reduces the need for future system calibration. You can use the PGA281 in industrial signal acquisition applications, including test and measurement, strain gauges, bridge amplifiers, and medical instrumentation.

Features of the PGA281 include:

- Zero-drift architecture: An offset voltage of 25 µV and an offset voltage drift of 174 nV/C with a maximum gain of 128 enables designers to optimise system performance. The offset voltage provides stability over a wide variety of conditions, including time and temperature.

- Best-in-class CMRR: More than 140 dB over a wide frequency range doubles the ability to reject common mode signals at unity gain. This allows minimal error when resolving changes in voltage.

- Wide range of internal gain options: Digitally programmable internal gain options and output scaling capabilities provide more than 20 unique gain selections. Programmable gain and attenuation allow for a wide input range of a few millivolts to greater than 20V, which makes the device a versatile front end.

- Internal error detection: An error flag pin indicates if an over-voltage or over-load condition has occurred, allowing the designer to monitor and maintain a clear signal.

The PGA281 comes in a 5 x 6.4-mm, 16-pin TSSOP package, specified over a temperature range of –40C to +105C, at $2.55 (1,000).

TI; www.ti.com/pga281