摘要 |
A reference voltage supplying circuit is disclosed, wherein the circuit generates stable maximum reference voltage and minimum reference voltage to a pipeline Analog to Digital Converter (ADC) even if levels of a first reference voltage and a second reference voltage are changed. According to the present invention, the first reference voltage and a maximum feedback voltage are differentially amplified by a first operational amplifier, and the second reference voltage and a minimum feedback voltage are differentially amplified by a second operational amplifier. Furthermore, a feedback voltage generator generates a maximum feedback voltage and a minimum feedback voltage in response to output signals from the first and second operational amplifiers and feedbacks the voltages to the first and second operational amplifiers, such that if the first and second reference voltages are changed, the maximum and minimum feedback voltages are changed to enable the first and second operational amplifiers to output stable signals. A reference voltage generator is operated in response to the output signals from the first and second operational amplifiers to generate stable maximum and minimum reference voltages.
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