Band-gap reference voltage source having high power supply rejection ratio

Abstract

The invention discloses a band-gap reference voltage source having a high power supply rejection ratio. The band-gap reference voltage source comprises a band-gap reference core circuit, a preposition voltage stabilizing circuit, a reference voltage converting circuit, a power supply voltage division circuit and a starting circuit. The starting circuit provides an initial bias current for an operational amplifier in the band-gap reference core circuit after the starting circuit is electrified. The power supply voltage division circuit divides the power supply voltage so as to generate needed different power supply branch voltages. The preposition voltage stabilizing circuit provides the pre-regulation voltage for the band-gap reference core circuit. The reference voltage converting circuit determines output states of the band-gap reference core circuit, and then selects the band-gap reference core circuit output or the power supply branch voltages to serve as the reference voltage. The band-gap reference core circuit outputs the band-gap reference voltage. According the invention, the power supply rejection ratio of the band-gap reference voltage source can be increased.

Description

technical field [0001] The invention relates to a voltage reference source technology, in particular to a bandgap reference voltage source with a high power supply rejection ratio, and the invention belongs to the field of integrated circuits. Background technique [0002] In the design of analog and digital-analog hybrid circuits, the reference voltage source can provide a stable reference voltage for the system, and other modules of the circuit, such as ADC and DAC, have strict requirements on the stability of the reference voltage module. Therefore, a well-designed reference voltage source is very necessary. The bandgap reference voltage source has become a widely used reference voltage source because it can generate a reference voltage that has little relationship with the power supply voltage and temperature variation. [0003] Such as figure 1 Shown is the structure diagram of the traditional bandgap reference voltage source. The operational amplifier OP controls th...

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Problems solved by technology

[0004] However, the power supply rejection ratio of the above-mentioned bandgap reference voltage source is not high, which is easily affected by the noise introduced from the digital part of the circuit on the same chip, and it is difficult to meet the requirements of other high-precision modules for reference voltage stability.

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