microwatt

Microwatt (symbol μW, also written uW) is a unit of power in the International System of Units (SI) equal to one millionth of a watt (10^-6 W). The prefix micro- comes from the Greek mikros meaning small. In decimal form, 1 μW equals 0.001 milliwatt and 0.000001 watt. The symbol μ is the standard SI prefix mu letter; in environments lacking the mu character, u is often used.

Because microwatts represent very small power levels, the term is common in electronics, sensors, and energy-efficient devices. In battery-powered and sleep modes, devices may consume only a few μW; for example, a microcontroller in deep sleep at a supply of about 3.3 V might draw on the order of a few microamperes, corresponding to several μW of dissipation. Photovoltaic and energy-harvesting circuits for wearables or remote sensors may generate power in the μW range under low light.

Compared with other SI prefixes, microwatts lie between nanowatts (nW) and milliwatts (mW). Specifically: 1 mW = 1000 μW and 1 μW = 1000 nW. The term is widely used in specifications, datasheets, and measurement conventions to express tiny, yet measurable, power levels in systems where efficiency and battery life are critical.