A digitally programmable gain amplifier for ultra-low-power applications

摘要

This paper presents a subthreshold CMOS digitally programmable gain amplifier for ultra-low-power signal processing applications. The subthreshold MOS transistor technique is used to achieve low-power consumption of the proposed circuit. The structure is constituted by a class-AB current amplifier which can handle a wide input signal. The gain of the digitally programmable gain amplifier is regulated by using current digital signal level without switch requirements; hence low circuit complexity, low power consumption and low number of devices can be obtained. Also both non-inverting and inverting amplifiers can be easily obtained into one single topology. Using additional resistors to convert the current to the voltage, single-input and differential-input digitally programmable voltage gain amplifiers can be obtained. The proposed circuit is simulated using 0.5 mu m CMOS technology. The simulation results show that the proposed circuit consumes very low power from +/- 1.2 V power supply.