CN202663358U - Operational amplifier circuit for achieving zero starting-up noise - Google Patents

Abstract

The utility model discloses an operational amplifier circuit for achieving zero starting-up noise. The operational amplifier circuit comprises an amplifier and a starting-up noise control circuit, and is characterized in that the starting-up noise control circuit comprises a standby control unit, a power supply detection unit, a negative power supply module, a digital delay module, an oscillator module and a logical control module. The negative power supply module is in a charge pump structure and provides negative voltage for an operational amplifier. The oscillator module is used for providing clock signals for a negative power supply module charge pump, and is used for providing a clock for the digital delay module. According to the operational amplifier circuit, by means of logical control for the standby control unit, the power supply detection unit, the negative power supply module and the digital delay module, any module does not start up or is abnormal in the starting-up process, the circuit shields outputs and inputs to the ground, and therefore the zero starting-up noise of the preposed operational amplifier is achieved.

Description

A kind of operation amplifier circuit of realizing zero VGA CARD

Technical field

Preamplifier module of the present utility model has realized zero VGA CARD, has greatly reduced the impulsive disturbance to system, belongs to the Audio Signal Processing field.

Background technology

Along with a large amount of of consumer electronics product popularize, people are more and more higher to the quality requirement of audio signal, no matter be high-quality LED-TV, or the mobile electronic product of high-fidelity music center and modern popular, all extremely harsh requirement, the start-up noises of not noted by people before comprising have been proposed the noise of its audio frequency output.Suppressing VGA CARD also becomes the factor of a key of a high quality audio system, it also is a design module with challenge, VGA CARD in the past suppresses module, just remove to weaken VGA CARD by the mode of similar soft start, but removal that can not be real, and can not suppress continuous switching on and shutting down noise, so still can hear the noise of whip when most products is started shooting now.The negative pumping source technology of operational amplifier utilization of the present utility model and digital delay technology have realized zero VGA CARD, the impact of power supply electrifying, the impact of standby conversion has dropped to minimum, guarantees to offer the clean signal of whole audio system, realizes " zero noise transmission ".

The utility model content

The utility model purpose provides one and realizes that zero VGA CARD module application is in the audio frequency pre-amplification circuit.

The utility model adopts following technical scheme for achieving the above object:

A kind of operation amplifier circuit of realizing zero VGA CARD, comprise amplifier and VGA CARD control circuit, it is characterized in that: described VGA CARD control circuit comprises Opportunity awaiting control for linear unit, power supply detecting unit, negative supply module, digital delay module, oscillator module and Logic control module;

Described Opportunity awaiting control for linear unit comprises standby opening module and chip enable module responsible standby after power supply voltage start finishes is opened and startup is inner respectively reference current, reference power supply;

Described power supply detecting unit comprises power supply detection module and power supply amplitude and Detection of Stability module, and whether power supply reached preset voltage and in the whether stable output of certain detection time of power supply after detection chip started respectively, or the pulse of moment;

Described negative supply module provides negative voltage for charge pump construction for operational amplifier;

Described oscillator module is used to the negative supply Modular charge pump that clock signal is provided, and the clock that provides of digital delay module is provided;

Described digital delay module is used for realizing time-delay, before negative supply is not set up, output is closed by the digital delay module, prevent because negative supply is set up the interference of ripple and impact in the process, after negative supply is set up, the digital delay module guarantees that also in work the time-delay long enough guarantees that negative supply has time enough to set up;

Described Logic control module be used for to realize that Opportunity awaiting control for linear unit, power supply detecting unit, negative supply module, the arbitrary module of digital delay module are not activated and finishes or occur unusually, and circuit all will shield and be input to ground.

The utility model is by to the logic control of standby control unit, power supply detecting unit, negative supply module, digital delay module, and arbitrary module is not activated to be finished or occur unusually, and circuit all will shield and be input to ground.Thereby realize preamplifier zero VGA CARD.

Description of drawings

Fig. 1 is the utility model VGA CARD control circuit functional-block diagram;

Fig. 2 is the utility model circuit theory diagrams.

Embodiment

A kind of operation amplifier circuit of realizing zero VGA CARD as shown in Figure 1, comprise amplifier and VGA CARD control circuit, described VGA CARD control circuit comprises Opportunity awaiting control for linear unit, power supply detecting unit, negative supply module, digital delay module, oscillator module and Logic control module;

Described Opportunity awaiting control for linear unit comprises standby opening module and chip enable module responsible standby after power supply voltage start finishes is opened and startup is inner respectively reference current, reference power supply;

Described power supply detecting unit comprises power supply detection module and power supply amplitude and Detection of Stability module, and whether power supply reached preset voltage and in the whether stable output of certain detection time of power supply after detection chip started respectively, or the pulse of moment;

Described negative supply module provides negative voltage for charge pump construction for operational amplifier;

Described oscillator module is used to the negative supply Modular charge pump that clock signal is provided, and the clock that provides of digital delay module is provided;

Described digital delay module is used for realizing time-delay, before negative supply is not set up, output is closed by the digital delay module, prevent because negative supply is set up the interference of ripple and impact in the process, after negative supply is set up, the digital delay module guarantees that also in work the time-delay long enough guarantees that negative supply has time enough to set up;

Described Logic control module be used for to realize that Opportunity awaiting control for linear unit, power supply detecting unit, negative supply module, the arbitrary module of digital delay module are not activated and finishes or occur unusually, and circuit all will shield and be input to ground.

Its operation principle is as follows: circuit begins to start from power supply, is in holding state, and all output inputs pull down to ground, guarantee that any AC signal can't be input to chip internal, guarantee to produce without any noise in the power initiation process; The time-delay regular hour entered the standby opening module afterwards after power initiation finished, and opened the chip enable unit, also had this moment other three modules to close the output input; The chip enable module enters power supply detection module and power supply amplitude and Detection of Stability module after starting the foundation of reference voltage electric current, if this moment, power supply existed than great fluctuation process, circuit will be fixed on this detected state always, close input and output; If power supply is stable, there is not large ripple, this closing function is opened, and enters next startup module.The digital delay module, utilize the internal delay time module, provide certain detection time to the power supply detection module, power supply is normal in this time-delay, next step opens internal oscillator, oscillator has two purposes, the one, the clock signal of charge pump, the 2nd, before the clock of digital delay module, negative supply were not set up, output was closed by the digital delay module, prevent because negative supply is set up the interference of ripple and impact in the process, after negative supply was set up, the digital delay module guaranteed that also in work the time-delay long enough guarantees that negative supply has time enough to set up.The digital delay module reaches autoshutdown behind the 0.5ms of setting, opens input and output, enters normal operating state.All can close input and output at any status circuit very before this, close the path of any noise, realize zero noise start.

Claims (1)

1. operation amplifier circuit of realizing zero VGA CARD, comprise amplifier and VGA CARD control circuit, it is characterized in that: described VGA CARD control circuit comprises Opportunity awaiting control for linear unit, power supply detecting unit, negative supply module, digital delay module, oscillator module and Logic control module;

Described Opportunity awaiting control for linear unit comprises standby opening module and chip enable module responsible standby after power supply voltage start finishes is opened and startup is inner respectively reference current, reference power supply;

Described power supply detecting unit comprises power supply detection module and power supply amplitude and Detection of Stability module, and whether power supply reached preset voltage and in the whether stable output of certain detection time of power supply after detection chip started respectively, or the pulse of moment;

Described negative supply module provides negative voltage for charge pump construction for operational amplifier;

Described oscillator module is used to the negative supply Modular charge pump that clock signal is provided, and the clock that provides of digital delay module is provided;

Described digital delay module is used for realizing time-delay, before negative supply is not set up, output is closed by the digital delay module, prevent because negative supply is set up the interference of ripple and impact in the process, after negative supply is set up, the digital delay module guarantees that also in work the time-delay long enough guarantees that negative supply has time enough to set up;

Described Logic control module be used for to realize that Opportunity awaiting control for linear unit, power supply detecting unit, negative supply module, the arbitrary module of digital delay module are not activated and finishes or occur unusually, and circuit all will shield and be input to ground.

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