The Wide Input Range Automatic-Threshold Control Circuit for High Definition Digital Audio Interface

There have been many researches about optical receivers to realize high-definition multimedia home network. For example, automatic-gain control (AGC) and automatic-threshold control (ATC) techniques to realize optical receiver have already been introduced. When the authors design optical receiver using conventional ATC techniques in low supply voltage, bit error rate (BER) performance of optical receiver is deteriorated due to the threshold voltage of NMOS which is used in source follower. To improve BER performance, new scheme of ATC which is not affected by threshold voltage is needed. This paper proposes wide input range automatic-threshold control (ATC) circuit. Optical receiver adopting proposed ATC was fabricated using standard 0.25mum CMOS technology. It has minimum receivable power of -27 dBm at 20Mbps without external adjustment.