| 摘要 |
A bandgap reference circuit includes two diode-connected transistors and an operational amplifier. The operational amplifier is connected in a feedback arrangement so that the current passing through transistor is substantially the same. This means that the current density in each transistor differs. The output of the operational amplifier is a function of the base emitter voltages of the two transistors and is substantially temperature invariant. Each transistor has a supplemental capacitor connected between its collector and emitter. The capacitors are substantially equal in size and both are substantially larger than the parasitic capacitance of either transistor. As a result, the overall capacitance of each transistor is substantially the same giving the reference circuit a favorable power supply rejection ratio.
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