Startup and shutdown mute circuit suitable for digital power amplifier IC

Abstract

The utility model relates to an on-off mute circuit suitable for a digital power amplifier IC. The on-off mute circuit comprises an input end VCC, an output end MUTE, a resistor R1, a diode D1, a resistor R2, a diode D2, a capacitor C1, a triode Q1, a three-end voltage stabilizer U1, a resistor R6, a capacitor C2 and a triode Q2. When the power amplifier is started, a high level is output through the resistor R1, the diode D1 and the output end MUTE, and the power amplifier is muted; and meanwhile, the input end VCC charges the capacitor C1 through the resistor R2, the voltage of the capacitor C1 is gradually increased, and when the voltage is higher than 5.8 V, the triode Q1 is conducted to the ground, and the output end MUTE is changed from high to low, so that the starting-up mute task is completed. During shutdown, the capacitor C2 discharges electricity to the ground through the diode D3 and the resistor R6, the base electrode of the triode Q2 is lowered, the triode Q2 is conducted, the capacitor C3 enables the output end MUTE to output high level through the resistor R5, and the shutdown mute task is completed.

Description

Technical Field

[0001] The utility model relates to circuit electronic technology, in particular to a switch mute circuit suitable for a digital power amplifier IC. Background Art

[0002] Most digital amplifier ICs are protected against power-on and power-off shocks by using MCU single-chip control. Because the time difference of MCU power-on during startup cannot be controlled in time, the MCU is also powered off at the same time when the power is turned off, which is equivalent to being out of control. This method is not only difficult to debug, but also cannot completely solve the power-on and power-off shock problem. For some audio products that do not require MCU single-chip control, if an MCU is added only to solve the power-on and power-off shock problem, the cost will also increase accordingly. Summary of the invention

[0003] The technical problem to be solved by the utility model is to provide a switch mute circuit suitable for a digital power amplifier IC, which has fast control response, low cost and convenient debugging.

[0004] In order to solve the above technical problems, the technical solution of the utility model is: a switch mute circuit suitable for a digital power amplifier IC, comprising an input terminal VCC, an output terminal MUTE, a resistor R1, a diode D1, a resistor R2, a diode D2, a capacitor C1, a transistor Q1, a three-terminal voltage regulator U1, a resistor R6, a capacitor C2 and a transistor Q2; the input terminal VCC is respectively connected to the input terminal of the three-terminal voltage regulator, one end of the resistor R1, one end of the resistor R2 and the cathode of the diode D2, the other end of the resistor R1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the output terminal MUTE, the anode of the diode D1 is connected to the collector of the transistor Q1, the emitter of the transistor Q1 is grounded, and the base of the transistor Q1 is respectively connected to the other end of the resistor R2, the diode The anode of D2 is connected to the positive electrode of the capacitor C1, the negative electrode of the capacitor C1 is grounded, the output end of the three-terminal regulator is respectively connected to one end of the resistor R6, the cathode of the diode D3, one end of the resistor R3, and the anode of the diode D4, the other end of the resistor R6 is grounded, the anode of the diode D3 is connected to the positive electrode of the capacitor C2, the negative electrode of the capacitor C2 is grounded, the other end of the resistor R3 is connected to the positive electrode of the capacitor C2 through the resistor R4, the emitter of the transistor Q2 is connected to the cathode of the diode D4, the base of the transistor Q2 is connected between the resistor R3 and the resistor R4, the collector of the transistor Q2 is connected to the anode of the diode D5, the cathode of the diode D5 is connected to the output end MUTE, and the cathode of the diode D4 is grounded through the resistor R5 and the capacitor C3 in sequence. The principle of the utility model: when the power is turned on, a high level is output through the resistor R1, the diode D1, and the output terminal MUTE to mute the power amplifier; at the same time, the input terminal VCC charges the capacitor C1 through the resistor R2, and the voltage of the capacitor C1 gradually increases. When it is higher than 5.8V, the transistor Q1 is turned on to the ground, and the output terminal MUTE changes from high to low, completing the task of turning on and muting. When the power is turned off, the capacitor C2 is discharged to the ground through the diode D3 and the resistor R6, the base of the transistor Q2 becomes low, the transistor Q2 is turned on, and the capacitor C3 makes the output terminal MUTE output a high level through the resistor R5, completing the task of turning off and muting.

[0005] Compared with the prior art, the utility model has the following beneficial effects:

[0006] The utility model adopts hardware circuit design, has fast control response, low cost and convenient debugging, and is suitable for any audio product that supports or does not support MCU control. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is the circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0008] The utility model will be further described below in conjunction with the accompanying drawings.

[0009] like Figure 1 As shown, a power-on / off mute circuit suitable for a digital power amplifier IC can be applied to a digital power amplifier IC, and the power-on / off mute circuit includes an input terminal VCC, an output terminal MUTE, a resistor R1, a diode D1, a resistor R2, a diode D2, a capacitor C1, a transistor Q1, a three-terminal voltage regulator U1, a resistor R6, a capacitor C2 and a transistor Q2; the input terminal VCC is respectively connected to the input terminal of the three-terminal voltage regulator, one end of the resistor R1, one end of the resistor R2 and the cathode of the diode D2, the other end of the resistor R1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the output terminal MUTE, the anode of the diode D1 is connected to the collector of the transistor Q1, the emitter of the transistor Q1 is grounded, and the base of the transistor Q1 is respectively connected to the other end of the resistor R2, the diode The anode of D2 is connected to the positive electrode of the capacitor C1, the negative electrode of the capacitor C1 is grounded, the output end of the three-terminal regulator is respectively connected to one end of the resistor R6, the cathode of the diode D3, one end of the resistor R3, and the anode of the diode D4, the other end of the resistor R6 is grounded, the anode of the diode D3 is connected to the positive electrode of the capacitor C2, the negative electrode of the capacitor C2 is grounded, the other end of the resistor R3 is connected to the positive electrode of the capacitor C2 through the resistor R4, the emitter of the transistor Q2 is connected to the cathode of the diode D4, the base of the transistor Q2 is connected between the resistor R3 and the resistor R4, the collector of the transistor Q2 is connected to the anode of the diode D5, the cathode of the diode D5 is connected to the output end MUTE, and the cathode of the diode D4 is grounded through the resistor R5 and the capacitor C3 in sequence. The principle of the utility model: when the power is turned on, a high level is output through the resistor R1, the diode D1, and the output terminal MUTE to mute the power amplifier; at the same time, the input terminal VCC charges the capacitor C1 through the resistor R2, and the voltage of the capacitor C1 gradually increases. When it is higher than 5.8V, the transistor Q1 is turned on to the ground, and the output terminal MUTE changes from high to low, completing the task of turning on and muting. When the power is turned off, the capacitor C2 is discharged to the ground through the diode D3 and the resistor R6, the base of the transistor Q2 becomes low, the transistor Q2 is turned on, and the capacitor C3 makes the output terminal MUTE output a high level through the resistor R5, completing the task of turning off and muting.

Claims

1. A power on / off mute circuit suitable for a digital power amplifier IC, characterized in that: The invention comprises an input terminal VCC, an output terminal MUTE, a resistor R1, a diode D1, a resistor R2, a diode D2, a capacitor C1, a transistor Q1, a three-terminal voltage regulator U1, a resistor R6, a capacitor C2 and a transistor Q2; the input terminal VCC is respectively connected to the input terminal of the three-terminal voltage regulator, one end of the resistor R1, one end of the resistor R2 and the cathode of the diode D2, the other end of the resistor R1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the output terminal MUTE, the anode of the diode D1 is connected to the collector of the transistor Q1, the emitter of the transistor Q1 is grounded, the base of the transistor Q1 is respectively connected to the other end of the resistor R2, the anode of the diode D2 and the positive electrode of the capacitor C1, the capacitor C 1 is grounded, the output end of the three-terminal regulator is respectively connected to one end of a resistor R6, a cathode of a diode D3, one end of a resistor R3, and an anode of a diode D4, the other end of the resistor R6 is grounded, the anode of the diode D3 is connected to the positive electrode of a capacitor C2, the negative electrode of the capacitor C2 is grounded, the other end of the resistor R3 is connected to the positive electrode of the capacitor C2 through the resistor R4, the emitter of the transistor Q2 is connected to the cathode of the diode D4, the base of the transistor Q2 is connected between the resistor R3 and the resistor R4, the collector of the transistor Q2 is connected to the anode of a diode D5, the cathode of the diode D5 is connected to the output end MUTE, and the cathode of the diode D4 is grounded through the resistor R5 and the capacitor C3 in sequence.

Images