A diode-less compact voltage/frequency reference-in-one

A circuit class of Voltage References is introduced, built by modifying a Widlar bandgap cell to incorporate a non-linear switched-capacitor resistor realized with a VCO (f-VR) or a var actor (c-VR). Since it is not based on diodes the reference is suited to low supplies, and tolerates high levels of total ionizing dose for extreme rad-hard applications. Autonomous f-VRs then provide a compact voltage/frequency reference-in-one. f-VR prototypes fabricated in 90nm CMOS exhibit 7ppm/°C voltage TC and <;-45dB PSR, with 15ppm/°C and <;0.9%/V frequency stability over -40/+120°C with an internal opamp. Performance improvements to -68dB PSR, 0.03%/V frequency stability were further demonstrated by testing with an external chopped opamp.