One solution for CMOS precision rectifier

Nano–power‐integrated precision rectifiers for implantable medical devices

“…But the development of such rectifiers is not trivial, firstly not only because of the power consumption of the operational amplifiers associated to classical rectifiers like the one in Figure 1B (dozens similar embodiments exist) but also because floating diodes are not always available in standard CMOS technology mainly due to latchup issues. The problem is challenging to such an extent that there are several published works and some patents proposing different rectifier topologies, most using either diodes and operational amplifiers, or a comparator or an equivalent structure to change an amplifier's configuration between ±1 gain depending on the sign of the input signal 1–14 …”

“…The problem is challenging to such an extent that there are several published works and some patents proposing different rectifier topologies, most using either diodes and operational amplifiers, or a comparator or an equivalent structure to change an amplifier's configuration between ±1 gain depending on the sign of the input signal. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] In the present work, the development of precision CMOS-integrated rectifiers with a current consumption down to a few nanoampere and using no diodes is presented, including measurement results on fabricated CMOS-integrated circuits. First, a rectifier transconductor named G mRect is shown, consuming only a 120-nA supply current.…”