| 摘要 |
A switched capacitor (SC) network is used in conjunction with a single PN junction to form a switching bandgap reference voltage circuit. The circuit includes an amplifier having an inverting input, a noninverting input, and an output; a first capacitor having a first capacitance (C1) coupled between the amplifier inverting input and a first common voltage source; a second capacitor having a second capacitance (C2) coupled between the amplifier inverting input and the amplifier output; a transistor having a base, a collector, and an emitter, the base and collector being coupled to the first common voltage source, and the emitter being coupled to the amplifier noninverting input. Two current sources are coupled to the transistor to bias the transistor to a one level during a precharge mode and a second, higher level during a reference voltage mode. A switch is connected in parallel with the second capacitor. The switch is opened during the precharge mode and closed during the reference voltage mode wherein a bandgap reference voltage (Vo) is produced at the amplifier output during the reference voltage mode equal to: V0=VBE2+(C2/C1)x(VBE2-VBE1). |
