Input offset voltage
Encyclopedia
Input offset voltage is the differential
DC voltage
required between the inputs of an amplifier
, especially an operational amplifier
, to make the output zero (0 volts with respect to ground, or between differential outputs if they exist, for voltage amplifiers).
Differential amplifier
A differential amplifier is a type of electronic amplifier that amplifies the difference between two voltages but does not amplify the particular voltages.- Theory :Many electronic devices use differential amplifiers internally....
DC voltage
Voltage
Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
required between the inputs of an amplifier
Amplifier
Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...
, especially an operational amplifier
Operational amplifier
An operational amplifier is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output...
, to make the output zero (0 volts with respect to ground, or between differential outputs if they exist, for voltage amplifiers).
- Typical values are around 1-10mV for cheap commercial-grade operational amplifierOperational amplifierAn operational amplifier is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output...
integrated circuits, but can be a few microvolts if nulled (assuming the IC has offset null pins for external adjustment circuits) and/or if higher quality (perhaps laser-trimmed) devices are used, although this may drift with temperature or age. - Chopper amplifiers are used to reduce offset voltages.
- Input current (and input offset current) will affect the offset voltage unless low impedance signal sources are used; FETFetFet is a municipality in Akershus county, Norway. It is part of the Romerike traditional region. The administrative centre of the municipality is the village of Fetsund.Fet was established as a municipality on 1 January 1838...
-input operational amplifiers tend to be better in this respect.