Low-voltage, low-power operational transconductance amplifier using novel current-mirrors

In this paper, a new complementary metal oxide semiconductor (CMOS) low-voltage, low-power operational transconductance amplifier (OTA) using current-reuse-current-mirror (CRCM) based on chartered 0.18 μm CMOS technology is presented. Because of the new CRCM technique and negative resistance load used in the OTA, the post-layout simulation results demonstrate that the CRCM OTA achieves DC gain of 48.1 dB, gain-bandwidth product of 117 MHz, phase margin of 62°; while the power consumption is only 45.58 μW with ± 0.7 V supply voltages. Moreover, in the current-reuse stage, the passive resistors are replaced by n-channel MOS transistors, which not only make the OTA consists of only active MOS transistors, but also make the DC gain of the OTA can be electronically and continuously controlled by the bias voltage, and the tuning range is from 0 to 48.1 dB. The chip area including test pads is only 0.09×0.12 mm2. The cadence post-layout simulation results are provided to verify all the theoretical analysis. © Institution of Engineers Australia, 2014.