GBWP

GBWP stands for gain-bandwidth product, a commonly used parameter to describe the frequency response of linear amplifiers and related active circuits. In simple single-pole models, an amplifier’s open-loop gain falls with frequency due to a dominant pole. The GBWP provides a convenient summary of this behavior: for a given feedback configuration, the closed-loop gain and the corresponding bandwidth multiply to a roughly constant value. Equivalently, GBWP is often interpreted as the open-loop dc gain multiplied by the dominant-pole frequency, and it also equals the unity-gain bandwidth in a single-pole system.

Measurement and units typically use Hz or MHz and are provided in device data sheets. The unity-gain bandwidth (the frequency where the closed-loop gain equals one) is closely related to the GBWP and serves as a practical reference point. In many designs, the product of the closed-loop gain and its bandwidth remains approximately constant over a range of gains, until higher-order poles or nonlinear effects become significant.

Practical implications: GBWP limits the achievable closed-loop bandwidth for a desired gain. If the required gain-bandwidth product exceeds the GBWP, the amplifier cannot preserve the intended gain across the target frequency range, leading to attenuation or phase distortion. Real devices deviate from the ideal single-pole model due to extra poles, output limitations, and temperature dependence, which can affect phase margin and stability.

Applications: GBWP is used in selecting amplifiers for filters, sensing and instrumentation, video, and RF circuits, where a balance between gain and bandwidth is essential. It helps engineers predict performance and ensure adequate speed for a given closed-loop configuration.