A 50 dB variable gain amplifier using parasitic bipolar transistors in CMOS

[1]  Cheng-Chung Shih,et al.  A CMOS analog front end for 9600BPS facsimile modem , 1987, 1987 IEEE International Solid-State Circuits Conference. Digest of Technical Papers.

[2]  R. Gregorian,et al.  A programmable gain/loss circuit , 1987 .