Low temperature coefficient reference voltage source applied to lvds driving circuit

Abstract

The invention relates to the field of integrated circuits, and provides a low-temperature coefficient reference voltage source circuit. A low-temperature coefficient reference voltage can be obtained within a wide temperature range, the circuit can be manufactured through the CMOS technology without additional processing steps, and the circuit manufacturing cost is saved. Therefore, by means of the technical scheme, a low-temperature coefficient reference voltage source for an LVDS drive circuit is composed of an NMOS transistor NX, a PMOS transistor P1, a PMOS transistor P2, a resistor R2a, a resistor R2b, a resistor R1 and an amplifier OTA. The low-temperature coefficient reference voltage source is mainly applied in the integrated circuit design and manufacturing occasions.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a reference voltage circuit design capable of providing a low temperature coefficient. Specifically, it relates to a low temperature coefficient reference voltage source applied to LVDS drive circuits. Background technique [0002] LVDS is a commonly used high-speed interface circuit, and its output signal is a low-voltage differential signal with a common mode level of 1.2V and a swing of 350mV. In order to stabilize the common-mode level of the output signal of the LVDS driving circuit at 1.2V, the LVDS driving circuit usually needs a common-mode feedback circuit, and the common-mode feedback circuit needs an accurate reference voltage source. Since the LVDS output signal has very strict requirements on the common-mode level, the voltage source must be very accurate, that is to say, the temperature coefficient of the reference voltage should be low. [0003] The traditional...

AI Technical Summary

Problems solved by technology

Although the traditional CMOS process is compatible with the PNP triode, but one end of the triode is connected to the substrate, so the injection current of the triode substrate can easily cause the problem of lining bias, resulting in the instability of the reference voltage; in addition, although the traditional CMOS process can Compatibility with PNP transistors is achieved, but additional process steps need to be introduced, and the number of masks needs to be increased, resulting in an increase in circuit manufacturing costs

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