An auto-input-offset removing floating gate pseudo-differential transconductor

A floating-gate pseudo-differential transconductor is presented, in which the differential input signal is allowed to have a dc offset. Normally such an offset would render a normal CMOS differential pair useless. The circuit inherently removes any dc offset from the floating gates by feedback mechanisms involving Fowler-Nordheim electron tunneling and hot-electron injection. This technique can enable direct cascading of several cells without amplifying and accumulating offsets, or can be used to generate differential current mode signals from a single voltage source that has a dc offset, as with an electret microphone.