Differential peak detection for outputting a signal indicative of a peak
value of an input signal. The input signal is differentially amplified
using common mode feedback and a common mode output is thereby output,
wherein common mode level of the common mode output is substantially the
same as a common mode voltage. The common mode output of such
differential amplification is coupled to an input of a first common
source input pair, and the common mode voltage and a feedback from the
output signal across a sampling capacitor is coupled to an input of a
second common source input pair. A summation of respective outputs of the
first and second common source input pairs is coupled to an input of a
transconductance stage, wherein an output of the transconductance stage
controls charging of the sampling capacitor. In this manner, a more
accurate output signal is provided.