Biasing circuit

Abstract

Disclosed is a biasing circuit. The biasing circuit comprises a positive temperature coefficient bias current generating circuit, a negative temperature coefficient bias current generating circuit, aconstant temperature voltage generating circuit and a constant temperature current generating current, wherein the positive temperature coefficient bias current generating circuit is used for generating a biasing current IB1 with a positive temperature coefficient; the negative temperature coefficient bias current generating circuit is used for generating a biasing current IB2 with a negative temperature coefficient; the constant temperature voltage generating current is used for generating a constant temperature voltage Vref related to the positive temperature coefficient biasing current IB1and the negative temperature coefficient biasing current IB2; and the constant temperature current generating current is used for generating a constant temperature current Iref related to the positivetemperature coefficient biasing current IB1 and the negative temperature coefficient biasing current IB2. By virtue of the biasing circuit, a voltage source and a current source can be generated at the same time, and the biasing circuit has the advantage of a small area as a CMOS biasing circuit as well as high PSRR and low low-temperature drift characteristics as a traditional Bipolar circuit.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a bias circuit capable of simultaneously generating a constant temperature current source and a constant temperature voltage source. Background technique [0002] With the development of integrated circuits, the chip area is gradually reduced. Bias voltage source and bias current source are two essential signal sources in the operation of analog integrated circuits. In the traditional design, the bipolar (bipolar) tube is used to generate bias voltage and bias current. Although better PSRR and better temperature drift characteristics can be obtained, it occupies a large area of ​​the circuit. The bias circuit designed with pure CMOS devices can effectively save the circuit area, but its PSRR and temperature drift performance are relatively poor. [0003] figure 1 It is a common bias circuit designed by pure CMOS devices. In this circuit, M1~M4 tubes and resistor R B Generat...

AI Technical Summary

Problems solved by technology

The PSRR cannot meet the requirements in many high-precision circuits

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