Abstract: A novel low-power exponential current generator used for VGA is proposed in this paper. This generator adopts a MOSFET biased in sub-threshold region to generate exponential current. To compensate the variation of process and temperature, a threshold detector and a system solution are proposed. The exponential current generator is verified in TSMC 0.18μm standard CMOS technology. Within a ±0.41 dB error, the dynamic range of the proposed exponential current generator is 30 dB. The power consumption is 11μW, and the minimum power source voltage is 0.9V.