V1mA

V1mA is a label sometimes encountered in electronics contexts, but it is not a standardized component or specification. In many documents, V1mA refers to the voltage that occurs at a point when a current of 1 milliampere is present in the circuit. Because it is not formally defined, its exact meaning depends on the context of the schematic, datasheet, or test setup.

In practical terms, V1mA can be interpreted in a few ways. If a resistor with resistance R carries 1 mA, the voltage across it is V1mA = I × R, or V1mA = 0.001 × R. In other cases, V1mA may denote the voltage required to drive a 1 mA load, such as the supply voltage or the input voltage at a node when a 1 mA current is drawn. It can also mark a measurement reference point on a current source or on an I–V characteristic curve where the current level is 1 mA.

Because the meaning can vary, it is important to consult the specific document for a definition if V1mA is encountered. Ambiguity can arise when multiple currents or reference points are discussed in the same schematic or datasheet.

See also: Ohm’s law, I–V characteristics, Thevenin equivalent, current source, test point, voltage reference.