attenuator pad [pad]

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(n.) In electronics, a passive network that reduces the voltage or power level of a signal with negligible distortion, but with insertion loss. It is typically a simple resistive network, although any combination of inductors, resistors, and capacitors may be used. A pad may also provide impedance matching. Pads are named according to the topology of the network they form, with the two most common being an L-pad and a T-pad. An L-pad is a two-legged network shaped like a backward letter “L.” It usually consists of two resistors that are fixed or adjustable. A variable L-pad consists of two variable potentiometers that are ganged together. The ganged sections work to provide either constant input or constant output impedance regardless of the attenuation setting. The term is used generally to include all L-shaped networks. Volume and level controls are examples. A T-pad is a three-legged network shaped like a letter “T.” It consists of three resistors that are fixed or adjustable. A variable T-pad consists of two or three variable potentiometers that are ganged together.