5mA

5mA, or five milliamperes, is a unit of electric current equal to one thousandth of an ampere. It is commonly used in electronics to specify small currents in low-power circuits. For example, many indicator LEDs draw around 5mA when operating at their typical forward voltage. Microcontrollers and digital sensors often source or sink current in the range of a few milliamperes for communication lines such as I²C or UART.

The ampere is the SI base unit for current, and the milliamperes notation (mA) indicates a multiplier of 10⁻³. Thus, 5mA = 0.005 amperes. In terms of charge flow, one ampere equals one coulomb per second, so 5mA corresponds to a charge transfer rate of 0.005 coulombs per second.

In practical circuits, 5mA is often considered within the safe operating limits of many plastic and ceramic capacitors and standard signal pins on integrated circuits. However, sustained currents at or above this level can cause heating in thin wires or long traces; designers typically use trace widths or wire gauges that accommodate expected current densities to minimize temperature rise.

Regulated power supplies for micro‑control units may provide 3.3 V or 5 V rails with a 5mA current limit to protect against accidental overload. Circuit designers use voltage dividers or current‑limiting series resistors to restrict currents to 5mA when driving sensors or display drivers that require that amount of current for proper operation.