A mute drive circuit and a vehicle-mounted device

Abstract

The embodiments of the invention provide a mute drive circuit and a vehicle-mounted device and relates to the technical field of electronics. The invention aims to solve the problem that POP sound is generated before a mute circuit executes a mute mode during shutdown operation of a vehicle-mounted device. The mute drive circuit comprises a voltage detection circuit, an inverter, an OR gate, and a mute control circuit. The voltage detection circuit detects a low level when an external electric power source is shut down and outputs the low level to the inverter; the inverter converts the low level into high level and outputs the high level to a first input end of the OR gate; the OR gate outputs the high level to a MUTE pin position of the mute control circuit when the high level is input at any of the first input end of the OR gate and a second input end of the OR gate; the mute control circuit executes a mute mode when the high level is input at the MUTE pin position of the mute control circuit. A method provided by the embodiments of the invention is used for eliminating POP sound during shutdown of a vehicle-mounted device.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a mute drive circuit and vehicle-mounted equipment. Background technique [0002] With the development of electronic technology, more and more vehicle-mounted devices such as car phones, car stereos and car radios are produced thereupon, which brings convenience to people's life and travel; The power supply capacitor is discharged, which is easy to generate POP sound, and the user experience is poor. [0003] CN 103313169 A By setting a mute drive circuit in the vehicle-mounted device, when the vehicle-mounted device is turned off, the mute drive circuit works and executes the mute mode, so that the user cannot hear the POP sound. Wherein, the mute driving circuit can output a high level through its control terminal to execute the mute mode. Specifically: when performing the shutdown operation of the vehicle-mounted device, the microcontroller can be controlled by software ...

AI Technical Summary

Problems solved by technology

[0005] Embodiments of the present invention provide a mute drive circuit and a vehicle-mounted device to solve the problem that a POP sound will still be generated before the mute circuit performs mute when the vehicle-mounted device is turned off.

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