Reference voltage generator with op-amp buffer

摘要

A reference voltage circuit and method making same, the reference voltage circuit including: a first sub-circuit for generating first and second temperature-compensated voltages; a second sub-circuit configured to receive the first and second temperature-compensated voltages and generate first and second reference voltages based on the first and second temperature-compensated voltages, respectively; and a third sub-circuit configured to receive and change voltage levels of the first and second reference voltages, and output a third reference voltage.

主权项

1. A reference circuit, comprising:
a first sub-circuit for generating first and second temperature-compensated voltages; a second sub-circuit configured to receive the first and second temperature-compensated voltages and generate first and second reference voltages based on the first and second temperature-compensated voltages, respectively; a third sub-circuit configured to receive and change voltage levels of the first and second reference voltages, and output a third reference voltage, wherein an output impedance of the first sub-circuit is higher than an input impedance of the third sub-circuit and the second sub-circuit provides a voltage buffer between the first and third sub-circuits; wherein a first drain terminal of a first MOSFET transistor of the first sub-circuit is coupled to a positive input terminal of a second differential amplifier of the second sub-circuit and a positive input terminal of a first differential amplifier of the first sub-circuit is coupled to a positive input terminal of a third differential amplifier of the second sub-circuit, respectively, and wherein a standard variation of the third reference voltage over a temperature range of −25 to 125 degrees Celsius is less than 1.0%.