Reference voltage generator and method for providing multiple reference voltages

Abstract

The present invention relates to a reference voltage generator and a method for providing a plurality of reference voltages. The reference voltage generator comprises a voltage regulator, a band-voltage circuit and an amplifying circuit. The voltage regulator with an input node is coupled to an external power supply for generating a regulated voltage source. The band-gap voltage circuit includes a first resistor and a second resistor and a first transistor and a second transistor to generate a voltage difference between the base-to-emitter voltages of the first and the second transistors. The first resistor is coupled to the first transistor. The second resistor is coupled to the first resistor, the first transistor and a regulated voltage source, the second resistor is coupled to the first resistor and a first transistor for generating the first predetermined voltage in response to the voltage difference. The amplifier circuit is coupled to the first transistor of the band-gap voltage circuit for receiving a first amplifying signal and generating an amplified signal so as to regulate the regulated voltage source. The present invention can generate an input reference voltages according under the more supply source and can improve more voltage sources.

Description

technical field [0001] The present invention relates to a reference voltage generator, in particular to a reference voltage generator providing multiple reference voltages with a high power supply rejection ratio and a method thereof. Background technique [0002] Reference circuits generate reference voltages that are used in many semiconductor applications, including digital and analog devices. Maintaining the accuracy of these semiconductor applications is directly dependent on the stability of the reference voltage. High-performance digital or analog devices require a stable reference voltage that is immune to temperature variations, power supply variations, and noise. For example, the accuracy of analog-to-digital and digital-to-analog conversions is directly dependent on the accuracy of an internal reference, which is typically a voltage reference that can withstand power supply variations, noise, and temperature variations. [0003] A common solution to an internal ...

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Problems solved by technology

However, voltage buffering consumes more power and die area

[0009] figure 1 Another disadvantage of the bandgap reference voltage circuit shown is the input reference bias voltage V of the high gain amplifier circuit OS Impact

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