High-Precision Differential-Input Buffered and External Transconductance Amplifier for Low-Voltage Low-Power Applications

Abstract

Recently, the demand for low-voltage low-power integrated circuits design has grown dramatically. For battery-operated devices both the supply voltage and the power consumption have to be lowered in order to prolong the battery life. This paper presents an attractive approach to designing a low-voltage low-power high-precision differential-input buffered and external transconductance amplifier, DBeTA, based on the bulk-driven technique. The proposed DBeTA possesses rail-to-rail voltage swing capability at a low supply voltage of +/- 400 mV and consumes merely 62 mu W. The proposed circuit is a universal active element that offers more freedom during the design of current-, voltage-, or mixed-mode applications. The proposed circuit is particularly interesting for biomedical applications requiring low-voltage low-power operation capability where the processing signal frequency is limited to a few kilohertz. An oscillator circuit employing a minimum number of active and passive components has been described in this paper as one of many possible applications. The circuit contains only a single active element DBeTA, two capacitors, and one resistor, which is very attractive for integrated circuit implementation. PSpice simulation results using the 0.18 mu m CMOS technology from TSMC are included to prove the unique results.