Digitally controlled transconductor based on a quantum transconductance

A new CMOS digitally controlled negative-transconductance amplifier (DTA) and an application example of a 4-Bits-Digitally Controlled Oscillator (DCO) are presented in this paper. The DTA is based on the traditional Digital CMOS inverter topology. From simulation and under 1.2 volts supply voltage, the proposed DCO oscillates from 375MHz to 475MHz which is compatible with the Medical Implant Communication Service (MICS) frequency band. The maximum total power consumption is about 2.5mW and only 2.5nW in power-off mode. All simulations have been performed using a CMOS 130nm process design kit from STMicroelectronics.