1 research outputs found
Power-efficient single-stage class-AB OTA based on non-linear nested current mirrors
A novel approach to design low-power area-efficient
rail-to-rail output single-stage class-AB operational transconductance amplifiers (OTAs) with enhanced large- and small-signal
performance to drive large capacitive loads is presented. It is
based on a non-linear nested current mirror at the active load
of a splitted differential input pair biased in weak inversion that
boosts dynamic currents beyond their quiescent value directly
at the output branch. As a result, slew rate, DC gain, gainbandwidth product, settling time and noise performance are
improved without additional circuit elements or power consumption. An OTA prototype has been fabricated in a 180-nm CMOS
process, consuming a quiescent power of 2.9 µW from a supply
voltage of ±0.5 V and a silicon area of 0.001 mm2
. Measurement
results validate the advantages of the proposal, exhibiting positive
and negative slew rates of 110 V/ms and −58 V/ms, respectively,
and a gain-bandwidth product of 136 kHz with a phase margin
of 90â—¦
for a capacitive load of 160 pF.This work was supported by the Ministerio de Ciencia e Innovación (MCIN)/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 under Grant PID2019-107258RBC32