Bandgap voltage reference circuitry working under a wide supply range is
provided. The bandgap reference circuitry in accordance with the
invention may provide an accurate reference voltage for systems with a
supply voltage that may range from approximately 1.8V to approximately
5.5V. The circuitry may be designed using a standard process and standard
devices without requiring the use of special low-threshold devices or
deep N-well processes and may generate an internal regulated supply
voltage that may remain at a substantially stable voltage level, in spite
of variations in the power supply voltage. The bandgap reference
circuitry may further use a voltage clamping structure to reduce leakage
currents.