Temperature insensitive bandgap voltage generator tracking power supply variations

摘要

A circuit for generating a bandgap voltage that is insensitive to temperature. The circuit includes an amplifier with a feedback loop having a high impedance output current mirror controlled by transistors connected to an output from the amplifier. The current mirror provides proportional currents to a pair of resistors that are connected to inputs to the amplifier, a first input receiving a temperature sensitive voltage from a first of the resistors, and a second input receiving a voltage that is a combination of a temperature sensitive voltage across a second of the resistors and a temperature sensitive offsetting voltage. The second resistor may be tapped to provide a selectable bandgap voltage. A reference voltage for operating the generator may be obtained from a voltage division of supply voltage by two resistors of the same type.