摘要 |
The accuracy of a bandgap reference voltage generator that contains two n-p-n transistors, an operational amplifier and five resistors, is increased by the use of current compensation circuitry which includes a third n-p-n transistor with an emitter resistor and a current mirror circuit. A master leg of the current mirror circuit generates a first output current which is identical to base current needed by the two transistors of the bandgap voltage generator. A slave leg of the current mirror circuit generates a second output current which is identical to the first output current and which is coupled to bases of the two transistors of the bandgap reference voltage generator. Thus base current needed by the two transistors is supplied by the compensation circuitry. This improves the accuracy of the output voltage generated by the reference voltage bandgap generator.
|