Programmable Instrumentation Amps Are Fast, Accurate

Design specifically for industrial and instrumentation applications with large voltage ranges, the AD8250 and AD8251 digitally programmable instrumentation amplifiers operate with ±5-V to ±12-V power supplies while delivering a 12-MHz bandwidth and 0.5-μs settling time to 0.01%. The devices’ 1-μV/° C offset drift and 10 ppm/°C gain drift are the lowest of any programmable gain in-amp, according to the company. Leveraging ADI’s submicron iCMOS (industrial CMOS) process technology, the amplifiers draw only 3.5 mA and come in 10-lead MSOP (mini small-outline plastic) packages.

Users have the flexibility of being able to digitally adjust the amplifiers’ gain settings even after the devices have been designed into a system. The user interface allows designers to set the 2-bit gain control word in one of three ways. It can be latched using the clock input; it can be set within 1 μs in transparent mode, or the bits can be strapped to a high- or low-voltage potential, permanently setting the gain. The amplifiers are identical except for their gain settings. The AD8250 offers gains of 1, 2, 5, and 10. The AD8251 provides gains of 1, 2, 4, and 8.