Precision, Micropower, Single Supply Instrumentation Amplifier (Fixed Gain = 10 or 100)

The LT1101 establishes the following milestones: (1) It is the first micropower instrumentation amplifier, (2) It is the first single supply instrumentation amplifier, (3) It is the first instrumentation amplifier to feature fixed gains of 10 and/or 100 in low cost, space-saving 8-lead packages.

The LT1101 is completely self-contained: no external gain setting resistor is required. The LT1101 combines its micropower operation (75µA supply current) with again error of 0.008%, gain linearity of 3ppm, gain drift of 1ppm/°C. The output is guaranteed to drive a 2k load to ±10V with excellent gain accuracy.

Other precision specifications are also outstanding: 50µV input offset voltage, 130pA input offset current, and low drift (0.4µV/°C and 0.7pA/°C). In addition, unlike other instrumentation amplifiers, there is no output offset voltage contribution to total error.

A full set of specifications are provided with ±15V dual supplies and for single 5V supply operation. The LT1101 can be operated from a single lithium cell or two Ni-Cad batteries. Battery voltage can drop as low as 1.8V, yet the LT1101 still maintains its gain accuracy. In single supply applications, both input and output voltages swing to within a few millivolts of ground. The output sinks current while swinging to ground—no external, power consuming pull down resistors are needed.

Applications

* Differential Signal Amplification in Presence of Common Mode Voltage

* Micropower Bridge Transducer Amplifier

* Thermocouples

* Strain Gauges

* Thermistors

* Differential Voltage-to-Current Converter

* Transformer Coupled Amplifier

* 4mA to 20mA Bridge Transmitter

* Gain Error: 0.04% Max

* Gain Non-Linearity: 0.0008% (8ppm) Max

* Gain Drift: 4ppm/°C Max

* Supply Current: 105µA Max

* Offset Voltage: 160µV Max

* Offset Voltage Drift: 0.4µV/°C Typ

* Offset Current: 600pA Max

* CMRR, G = 100: 100dB Min

* 0.1Hz to 10Hz Noise:

* 0.9µVP-P: Typ

* 2.3pAP-P Typ

* Gain Bandwidth Product: 250kHz Min

* Single or Dual Supply Operation

* Surface Mount Package Available