A mode selectable field transmitter comprising: a housing; a sensor located within the housing that is adapted to generate an electrical signal representative of a sensed process variable; and transmitter circuitry located within the housing that is adapted to transmit an output to a receiver external to the housing based on the electrical signal provided by the sensor, wherein the transmitter circuitry is configurable to a plurality of operating modes having different combinations of function, performance, and power consumption, the transmitter circuitry including: an analog-to-digital (A/D) converter that is adapted to convert the electrical signals provided by the sensor to digital signals; an A/D bias circuit connected and adapted to regulate power provided to the A/D converter; and a controller that is adapted to electrically configure the transmitter circuitry to one of the plurality of operating modes in response to mode selection data received from a source external to the housing, characterised in that: for at least one of the operating modes, the A/D converter is adapted to be electrically configured by the controller to operate at an increased update rate; the A/D bias circuit is adapted to be electrically configured by the controller to increase the power provided to the A/D converter, such that a resulting decrease in power is available for other functions and components in the transmitter circuitry. a housing; a sensor located within the housing that is adapted to generate an electrical signal representative of a sensed process variable; and transmitter circuitry located within the housing that is adapted to transmit an output to a receiver external to the housing based on the electrical signal provided by the sensor, wherein the transmitter circuitry is configurable to a plurality of operating modes having different combinations of function, performance, and power consumption, the transmitter circuitry including: an analog-to-digital (A/D) converter that is adapted to convert the electrical signals provided by the sensor to digital signals; an A/D bias circuit connected and adapted to regulate power provided to the A/D converter; and a controller that is adapted to electrically configure the transmitter circuitry to one of the plurality of operating modes in response to mode selection data received from a source external to the housing, an analog-to-digital (A/D) converter that is adapted to convert the electrical signals provided by the sensor to digital signals; an A/D bias circuit connected and adapted to regulate power provided to the A/D converter; and a controller that is adapted to electrically configure the transmitter circuitry to one of the plurality of operating modes in response to mode selection data received from a source external to the housing, characterised in that: for at least one of the operating modes, the A/D converter is adapted to be electrically configured by the controller to operate at an increased update rate; the A/D bias circuit is adapted to be electrically configured by the controller to increase the power provided to the A/D converter, such that a resulting decrease in power is available for other functions and components in the transmitter circuitry. for at least one of the operating modes, the A/D converter is adapted to be electrically configured by the controller to operate at an increased update rate; the A/D bias circuit is adapted to be electrically configured by the controller to increase the power provided to the A/D converter, such that a resulting decrease in power is available for other functions and components in the transmitter circuitry.