公开(公告)号：US20240421780A1

公开(公告)日：2024-12-19

申请号：US18335459

申请日：2023-06-15

Applicant: Analog Devices, Inc.

Inventor： David J. McLaurin ,  Kevin Gard

IPC: H03F3/195 ,  H03F1/56 ,  H03G1/00 ,  H03G3/30

Abstract: Variable gain amplifiers (VGAs) with fine attenuation step control and flat signal-to-noise ratio (SNR) versus attenuation are provided. In certain embodiments, a VGA includes an input that receives a radio frequency (RF) input signal, a segmented amplification circuit including multiple amplification cells that operate in parallel to amplify the RF input signal to generate multiple amplified RF signals, an impedance ladder including multiple taps each connected to a different node of the impedance ladder, and switches that control routing of the amplified RF signals to one or more selected taps of the impedance ladder. Accordingly, the VGA uses the switches to connect the outputs of the segmented amplification circuit to the selected tap(s) of the impedance ladder. By changing the tap selection, the attenuation step of the VGA is controlled.