An apparatus can include tracking circuitry coupled to a current source and configured to generate a reference voltage signal based on a reference current signal from the current source. The apparatus can include voltage regulator circuitry coupled to the tracking circuitry and configured to generate a voltage supply signal based on the reference voltage signal. The apparatus can further include amplifier circuitry configured to amplify an input signal based on the voltage supply signal. The reference voltage signal can track process and temperature variations associated with at least one field effect transistor within the tracking circuitry. The voltage regulator circuitry can be configured to operate with a closed loop gain higher than 1. The tracking circuitry includes a first transistor connected in parallel with a second transistor, the first and second transistors having a complimentary type with each other (e.g., NMOS and PMOS transistors).