The LT®1167 is a low power, precision instrumentation amplifier that requires only one external resistor to set gains of 1 to 10,000 and is ideally suited to be used with board level pressure sensors. In fact the first circuit shown used a GE/NovaSensor NPC-1220 to make a simple barometer.
The LT1167 is a modified version of the three op amp instrumentation amplifier. Laser trimming and monolithic construction allow tight matching and tracking of circuit parameters over the specified temperature range. The LT1167 is laser trimmed for low offset voltage so that no external offset trimming is required for most applications.
The reference terminal is one end of one of the four 10k resistors around the difference amplifier. The output voltage of the LT1167 (Pin 6) is referenced to the voltage on the reference terminal (Pin 5). Resistance in series with the REF pin must be minimized for best common mode rejection. For single supply operation, the REF pin can be at the same potential as the negative supply (Pin 4) provided the output of the instrumentation amplifier remains inside the specified operating range and that one of the inputs is at least 2.5V above ground.
In addition, the LTC1167 has buildt in RFI reduction, and is suited well for almost all industrial applications.