| 摘要 |
PROBLEM TO BE SOLVED: To provide a gain control circuit that can reduce DC offset fluctuation in a base band signal at gain control. SOLUTION: In the configuration of the gain control circuit 10 where an output of a gain control amplifier 2 is negatively fed back to an input side sbutractor 5 via an amplifier 3 and an integrator 4 so as to decrease a DC gain, by controlling a gm (transconductance) of the integrator 4, in a way that the DC gain is constant in response to the gain control of the gain control amplifier 2, the DC offset fluctuation of a gain control circuit 10 can be reduced. Furthermore, this gain control circuit 10 can suitably be applicable to a base band section of a reception circuit of a wireless communication unit.
|
