Digitally Controlled AGC with Programmable-Gain Amplifier for DVB-T/H

This paper describes a digitally controlled automatic gain control (AGC) subsystem for the analog front-end (AFE) supporting the digital video broadcasting in DZIF (double conversion with zero second IF) architecture. The receive path contains a programmable-gain amplifier (PGA) with self-tuning gain circuit. The dynamic range of the PGA is 51 dB controlled by a digital loop to form a first order control system. The third-harmonic distortion is less than -60 dB for differential input signal up to 160 mVpp. The supply voltage used is 1.8 V and the power consumption of designed chip is 13 mW. The nonlinearity of the proposed design verified by HSPICE post-layout simulation is better than -60 dB at every MOS corner, which is suffcient for the system specification. This chip is fabricated on TSMC's standard 0.18 m 1P6M CMOS technology.