Micropower, Single-Supply, Rail-to-Rail, Precision Instrumentation Amplifiers

The MAX4194 is a variable-gain precision instrumentation amplifier that combines Rail-to-Rail; single-supply operation, outstanding precision specifications, and a high gain bandwidth. This amplifier is also offered in three fixed-gain versions: the MAX4195 (G = +1V/V), the MAX4196 (G = +10V/V), and the MAX4197 (G = +100V/V). The fixed-gain instrumentation amplifiers feature a shutdown function that reduces the quiescent current to 8µA. A traditional three operational amplifier configuration is used to achieve maximum DC precision.

The MAX4194–MAX4197 have rail-to-rail outputs and inputs that can swing to 200mV below the negative rail and to within 1.1V of the positive rail. All parts draw only 93µA and operate from a single +2.7V to +7.5V supply or from dual ±1.35V to ±3.75V supplies. These amplifiers are offered in 8-pin SO packages and are specified for the extended temperature range (-40°C to +85°C).

See the MAX4198/MAX4199 data sheet for single-supply, precision differential amplifiers.

Applications

* 4mA to 20mA Loop Transmitters * Battery-Powered/Portable Equipment * Bridge Amplifier * Data Acquisition Systems * Medical Equipment * Thermocouple Amplifiers * Transducer Interface

* Low Power Consumption Is Ideal for Remote-Sensing and Battery-Powered Applications

* +2.7V Single-Supply Operation

* Low Power Consumption

* 93µA Supply Current

* 8µA Shutdown Current (MAX4195/MAX4196/MAX4197)

* Precision Specifications Maximize Sensor Peformance

* High Common-Mode Rejection: 115dB (G = +10V/V)

* Input Common-Mode Range Extends 200mV Below GND

* Low 50µV Input Offset Voltage (G ≥ +100V/V)

* Low ±0.01% Gain Error (G = +1V/V)

* 250kHz -3dB Bandwidth (G = +1V/V, MAX4194)

* Rail-to-Rail Outputs