Low noise, gain enhanced circuits for low voltage low power CMOS systems

Low voltage low power specifications make difficult the integration of very high gain operational amplifiers; the classic method to achieve a gain enhancement together with both an offset and a low frequency, noise reduction is a proper autozeroing, which on the other hand significantly increases the effects of the input wideband noise. In this paper, the authors introduce dynamic matching of operational amplifiers, circuits using this principle may, achieve gain enhancement (together with both an offset and a low frequency noise reduction), without autozeroing, which results in better noise performances and thus in better accuracy.