Pin-Strapping Selects Internal Resistors To Set Gain

While traditional amplifiers use external resistors to set gain, a new amplifier family integrates on-board thin-film precision resistors that can be selected by pin-strapping. Users can configure the LT1991 and LT1995 as difference, summing, inverting, or non-inverting amplifiers with various gain options without using any external components. The precision LT1991 has a 560-kHz gain-bandwidth product. As a difference amp, gain is programmable from 1 to 13; as a non-inverting amp, from 0.07 to 14; and as an inverting amp, from −0.08 to −13, all with a guaranteed maximum gain accuracy of 0.04%. It has less than 50-mV input offset with a 50-pA input offset current. Offset voltage drift is 1 µV/°C, and gain drift is less than 3 ppm/°C. The amp has rail-to-rail output and operates on supplies from 2.7 to 36 V, drawing less than 110 mA from a single 5-V supply. The high-speed LT1995 offers a 32-MHz gain-bandwidth product. As a difference amp, gain is programmable from 1 to 7; as a non-inverting amp, from 1 to 8; and as an inverting amp, from −1 to −7, with a guaranteed maximum gain accuracy of 0.2%. It has less than 2.5-mV input offset. The LT1995 can slew at 1000 V/µs and settles to 0.1% in 100 ns. It operates on supplies from ±2.5 to ±15 V, drawing less than 9 mA. Thousand-piece pricing starts at $1.39 each for the LT1991 and $1.89 each for the LT1995.