A high dynamic range programmable gain amplifier for HomePlug AV powerline communication system

A high dynamic range programmable gain amplifier (PGA) for HomePlug AV powerline communication (PLC) receivers has been designed in a standard 0.18-μm CMOS technology. Linear transconductance amplifiers are employed as gain cells to obtain high dynamic range. A current compensation technique is proposed to achieve fine gain step characteristics. For constant settling time issue in automatic gain control (AGC) loop, a pseudo-exponential approximation is adopted. A 6-bit PGA suited for PLC receiver is realized by cascading PGA gain cell along with fixed gain amplifiers. The proposed PGA has been measured to exhibits a 3-dB bandwidth of more than 78 MHz and a dB-linear gain ranging from -24 to 74 dB with a maximum gain error of 0.24LSB. The core circuit consumes 1.9 mW through a 1.8 V supply, and occupies only 0.03 mm² active area.