Inherently accurate adjustable switched capacitor voltage reference with wide voltage range

A switched capacitor voltage reference including a single bias current source, three capacitors, diode devices, an amplifier and switching circuits for developing a temperature independent reference voltage. A single current source avoids having to match multiple current sources. A first capacitor and at least one diode device set a voltage having a negative temperature coefficient. A second capacitor and each of the diode devices set a voltage having a positive temperature coefficient. A third capacitor allows adjustable gain to enable a wide voltage range including a low voltage such as less than one volt. The switching circuits switch between multiple modes for developing and then combining the different temperature coefficient voltages. The topology allows a simple amplifier to be used. The topology is inherently accurate and does not require device trimming. An averaging method may be used to compensate for any mismatch between the diode devices.