In this paper, a novel variable-gain amplifier (VGA) and a novel voltage-controlled ring oscillator (VCRO) are proposed. The two proposed schemes depend on the same controlled inverter unit with a single added device. The relationship between the voltage gain of the proposed VGA and the control voltage and the relationship between the oscillation frequency of the proposed VCRO and the control voltage are both derived. Finally, the proposed VGA and VCRO are simulated adopting the 45 nm CMOS technology with a power-supply voltage, V DD , equal to 1 V.