A switched-capacitor programmable-gain amplifier for high-definition video analog front-ends

A switched-capacitor programmable gain amplifier (PGA) for high-definition video analog front-ends (AFEs) is presented. The PGA also acts as the sample and holder of the ADC to reduce the power consumption and chip area of the whole AFE. The 9-bit gain and offset control DACs are embedded into the switched capacitor networks of the PGA. Simulated results show that the PGA achieves a gain range of 0.9 to 2.4V/V, and an offset control range of -230 to 230mV while consuming 10.1mA from a 1.8V power supply. An AFE based on the proposed PGA is fabricated in TSMC 0.18μm process. Measurement results show that the AFE achieves the capability to process variant HDTV signals up to 1080p YPbPr and computer video signals up to UXGA (1600×1200 @75Hz).