Step-down voltage dividing bias circuit based on in-well high-voltage high-precision polycrystalline resistor

Abstract

The invention discloses a step-down voltage dividing bias circuit based on an in-well high-voltage high-precision polycrystalline resistor. The bias circuit includes two high-voltage-resistance high-precision polycrystalline resistor voltage dividing circuits, voltage self-bias circuits, bipolar composite triodes, series connection voltage dividing triodes, a series connection resistor voltage dividing circuit and a current bias circuit. The two high-voltage-resistance high-precision polycrystalline resistor voltage dividing circuits are in series connection, and are used for obtaining high voltage from a high-voltage port VDD, and obtaining sampling voltage VK after voltage dividing and step-down; stable voltage VQ is generated after the sampling voltage VK passes through the voltage self-bias circuits for voltage regulation; constant low-voltage bias voltage VCC is output after the stable voltage VQ passes through the bipolar composite triodes and the series connection voltage dividing triodes for voltage step-down and fine-adjustment; reference voltage VREF of various values is obtained after the constant bias voltage VCC passes through the series connection resistor voltage dividing circuit for voltage dividing; and at the same time, the current bias circuit utilizes the constant bias voltage VCC to produce multiple stable bias currents IBAS. An entire bias circuit networkincreases a circuit integration degree, reduces a chip area, and reduces costs.

Description

technical field [0001] The invention belongs to the technical field of analog integrated circuits, and in particular relates to a voltage-dividing bias circuit based on high-voltage and high-precision polycrystalline resistors in wells. Background technique [0002] In integrated circuit systems, it is common to contain bias networks. The function of the bias network is to provide a stable bias voltage or bias current to other modules inside the circuit, so that each module of the circuit can work well. However, in a general bias network, the power supply voltage of the bias network directly determines the process selection of internal circuit devices. Therefore, the withstand voltage requirements provided by the process of the internal devices of the circuit must match the size of the power supply voltage. Today's popular high-voltage BCD process can withstand tens of volts; for hundreds of volts or even hundreds of volts, it can only be realized by special devices, such ...

AI Technical Summary

Problems solved by technology

Therefore, the inaccuracy of MOS gate polysilicon growth is consistent with that of polysilicon resistance, which affects the accuracy of polysilicon resistance

On the other hand, when the existing polycrystalline resistor is used as a fuse, the polycrystalline resistor is usually made thicker, which makes it difficult to maintain the thickness of the silicided region and the non-silicided region, which makes it difficult to reduce the height of the gate

Images