The LT1991 combines a precision operational amplifier with eight precision resistors to form a one-chip solution for accurately amplifying voltages. Gains from –13 to 14 with a gain accuracy of 0.04% can be achieved using no external components. The device is particularly well suited for use as a difference amplifier, where the excellent resistor matching results in a common mode rejection ratio of greater than 75dB. The amplifier features a 50µV maximum input offset voltage and a gain bandwidth product of 560kHz. The device operates from any supply voltage from 2.7V to 36V and draws only 100µA supply current on a 5V supply. The output swings to within 40mV of either supply rail. The resistors have excellent matching, 0.04% over temperature for the 450k resistors. The matching temperature coefficient is guaranteed less than 3ppm/°C. The resistors are extremely linear with voltage, resulting in a gain non-linearity of less than 10ppm. The LT1991 is fully specified at 5V and ±15V supplies and from –40°C to 125°C. The device is available in space saving 10-lead MSOP and low profile (0.8mm) 3mm × 3mm DFN packages.
The LT1991 combines a precision operational amplifier with eight precision resistors to provide a one‑chip solution for accurate voltage amplification. Gains from –13 to 14 can be achieved without external components, with a gain accuracy of 0.04 % and a common‑mode rejection ratio greater than 75 dB. The device features a 50 µV maximum input offset voltage, 560 kHz gain‑bandwidth product, and rail‑to‑rail output swing within 40 mV of either supply rail.
It operates from a wide supply range of 2.7 V to 36 V, drawing only 100 µA at a 5 V supply. The LT1991 is offered in space‑saving 10‑lead MSOP and low‑profile 3 mm × 3 mm DFN packages and is suited for handheld instrumentation, medical instrumentation, strain‑gauge amplifiers, and differential‑to‑single‑ended conversion.
| Gain error | <0.04 % |
|---|---|
| Gain drift | <3 ppm/°C |
| CMRR | >75 dB |
| Supply voltage range | 2.7 V to 36 V |
| Supply current | 100 µA (5 V supply) |
| Output swing | within 40 mV of either rail |
| Gain‑bandwidth product | 560 kHz |
The device operates from any supply voltage between 2.7 V and 36 V.
The gain‑bandwidth product is 560 kHz.