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Operational amplifier for performing offset voltage correction on output working point

An operational amplifier, offset voltage technology, applied in the field of operational amplifiers, can solve problems such as poor accuracy

Active Publication Date: 2017-11-14
西安华泰半导体科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide an operational amplifier that performs offset voltage correction for the output operating point, so as to solve the problem of poor precision when performing offset voltage calibration at the operating point required by the user

Method used

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  • Operational amplifier for performing offset voltage correction on output working point
  • Operational amplifier for performing offset voltage correction on output working point
  • Operational amplifier for performing offset voltage correction on output working point

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] see figure 2 The main circuit of the operational amplifier includes: NMOS transistor MN101, NMOS transistor MN102, NMOS transistor MN103, NMOS transistor MN104, NMOS transistor MN105, NMOS transistor MN106, NMOS transistor MN107, NMOS transistor MN108, NMOS transistor MN109, NMOS transistor MN110, NMOS transistor MN111, NMOS transistor MN112, NMOS transistor MN113, NMOS transistor MN114, PMOS transistor MP101, PMOS transistor MP102, current source Ib101, current source Ib102, switch k101, switch k102, switch k103, switch a101, switch a102, switch a103, Switch a104, switch b0, switch b1, switch b2, switch b3, switch b4, switch b5, switch b6, capacitor C101.

[0029] see figure 2, the non-inverting input end of the operational amplifier is connected to the gate of the PMOS transistor MP102 through the switch k103, the inverting input end is connected to the gate of the PMOS transistor MP101 through the switch k101, one end of the switch k102 is connected to the gate of...

Embodiment 2

[0035] The structure of the operational amplifier in this embodiment is the same as that in Embodiment 1, and the gain stage in the main module of the operational amplifier is replaced with a telescopic operational amplifier structure.

[0036] see figure 2 , the main circuit of the operational amplifier includes: NMOS transistor MN201, NMOS transistor MN202, NMOS transistor MN203, NMOS transistor MN204, NMOS transistor MN205, PMOS transistor MP201, PMOS transistor MP202, PMOS transistor MP203, PMOS transistor MP204, PMOS transistor MP205, PMOS transistor MP206, PMOS transistor MP207, PMOS transistor MP208, PMOS transistor MP209, PMOS transistor MP210, PMOS transistor MP211, PMOS transistor MP212, PMOS transistor MP213, PMOS transistor MP214, PMOS transistor MP215, current source Ib201, current source Ib202, switch k201 , switch k202, switch k203, switch a201, switch a202, switch a203, switch a204, switch b201, switch b202, switch b203, switch b204, switch b205, switch b206, ...

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PUM

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Abstract

The invention relates to an operational amplifier for performing offset voltage correction on an output working point. The operational amplifier comprises an operational amplifier module, a comparator module, a logic control module, a correction logic module, an inter-integrated circuit (IIC) interface and a digital-to-analogue converter (DAC) module, wherein the IIC interface is connected with the DAC module, and an output end of the DAC module is connected with an in-phase input end of the comparator module; an inverting input end of the comparator module is connected with an output end (VOUT) of the operational amplifier module; an input end of the logic control module is connected with an output end of the comparator module; an output end of the logic control module is connected with an input end of the correction logic module. An offset correction process of the operational amplifier comprises coarse adjustment and fine adjustment; the coarse adjustment is carried out in a way of transistor parallel connection, and the fine adjustment is carried out in a way of transistor series connection, so that the correction accuracy is improved.

Description

technical field [0001] The invention belongs to the field of CMOS process integrated circuits, and in particular relates to an operational amplifier for correcting offset voltage for an output operating point. Background technique [0002] In the manufacturing process of the operational amplifier, due to the uncertainty of the CMOS manufacturing process and the mechanical pressure in the packaging process, the prepared operational amplifier inevitably has a certain offset voltage. As a result, when the amplifier is working normally, an unexpected error will always be superimposed on its output, which will inevitably have a certain impact on the performance of the entire circuit, especially the accuracy, especially in applications with small DC signals and high precision. There are many techniques to reduce or correct this offset voltage. Such as the use of larger transistors, self-zeroing and chopping techniques. During the correction process, it is necessary to add a comm...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H03F1/34H03F3/45H03G1/00H03G3/30
CPCH03F1/342H03F3/45179H03F2200/471H03F2203/45031H03F2203/45044H03G1/0088H03G3/30
Inventor 王红义范柚攸吴凯周罡曹灿
Owner 西安华泰半导体科技有限公司