Audio driving integrated circuit
By designing the audio amplifier circuit of the op amp U3 and U4, the series voltage divider circuit and the shutdown circuit of the NPN type transistor Q4 in the audio driving integrated circuit, the problem of the existing audio driving circuit continuously consumed power is solved, and the circuit is quickly shut down and stability improvement is achieved.
Patent Information
- Application Number
- CN202421375513.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-17
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-06-17
AI Technical Summary
Existing audio driver circuits have problems of continuous power consumption, resulting in increased power consumption, component overheating, drifting and performance degradation, and the inability to quickly shut down in case of overload or failure, affecting reliability and efficiency.
An audio driving integrated circuit is designed to amplify and output the audio signal through the op amp U3 and U4, and a series voltage divider circuit provides a stable reference voltage, and the circuit shutdown control is realized through the NPN type transistor Q4 and the switch S1.
The circuit is quickly shut down, avoid unnecessary current consumption, protect circuit components, prevent drift or temperature influence caused by long-term operation, enhance stability and reliability, and reduce power consumption.
Smart Images
Figure CN222691716U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of integrated circuits, in particular to an audio driver integrated circuit. Background Art
[0002] In modern audio driver circuits, audio power amplifiers are widely used to amplify and process audio signals. Traditional audio driver circuits usually include multiple op amps and their related circuits and feedback networks to achieve high-quality audio signal amplification. However, these circuits have some design flaws, especially the lack of an effective shutdown function.
[0003] The audio driver circuits in the prior art consume power continuously, generating unnecessary current consumption even when not in use. This not only increases the power consumption of the circuit, but can also cause component overheating, drift, and performance degradation. In addition, in the event of an overload or fault, conventional circuits cannot shut down quickly, which can easily cause damage to circuit components. Inadequate performance in power management and circuit protection limits their reliability and efficiency in practical applications. Utility Model Content
[0004] The utility model aims to provide an audio driver integrated circuit to solve the technical problem of the existing audio driver integrated circuit that continuously consumes electric energy.
[0005] To achieve the above purpose, the specific technical solution of an audio driver integrated circuit of the utility model is as follows:
[0006] An audio driver integrated circuit comprises an operational amplifier U3 and an operational amplifier U4, wherein the output ends of the operational amplifier U3 and the operational amplifier U4 are used to output audio signals, the non-inverting input ends of the operational amplifier U3 and the operational amplifier U4 are connected, and a series voltage divider circuit is provided for providing a reference voltage for the non-inverting input end; the output end of the operational amplifier U3 is connected to the inverting input end of the operational amplifier U4 through a resistor R6, the inverting input end of the operational amplifier U3 is used to input an audio signal, and a shutdown circuit is also provided, comprising an NPN-type transistor Q4, the collector of the transistor Q4 is connected to the non-inverting input end of the operational amplifier U4, the emitter of the transistor Q4 is grounded through a resistor R12, the base of the transistor Q4 is connected to a switch S1 outside the integrated circuit through a resistor R11, and the second end of the switch S1 is grounded; the first end of the switch S1 is connected to the resistor R11, and is connected to a power supply through a pull-up resistor R13.
[0007] Furthermore, the resistor R12 is connected in parallel with a capacitor C3.
[0008] Furthermore, the series voltage divider circuit includes a resistor R8 and a resistor R10, a first end of the resistor R8 is connected to a power supply and grounded through a capacitor C5, a second end of the resistor R8 is connected to a first end of the resistor R10, a second end of the resistor R10 is grounded, and a common node of the resistor R8 and the resistor R10 is respectively connected to the non-inverting input terminal of the operational amplifier U3.
[0009] Furthermore, the output terminal of the operational amplifier U3 is connected to the inverting input terminal thereof through the resistor R17 and the capacitor C6 respectively.
[0010] Furthermore, the inverting input terminal of the operational amplifier U3 is connected to the external audio input terminal through the resistor R18 and the capacitor C7 in sequence.
[0011] The audio driver integrated circuit provided by the utility model has the following advantages:
[0012] The audio driver circuit amplifies and outputs the audio signal through the operational amplifiers U3 and U4, provides a stable reference voltage through the voltage divider circuit, and realizes the circuit shutdown control through the transistor Q4 and the switch S1. The simple switch S1 is convenient for users to operate, and the shutdown function can quickly shut down the circuit to avoid unnecessary current consumption and protect the circuit components in the event of overload or fault. Prevent drift or temperature effects caused by long-term operation, and enhance stability and reliability. The shutdown circuit effectively reduces power consumption, improves system stability and reliability through the NPN transistor Q4 and a small number of external components, making it have high practical value in audio driver applications. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is the internal functional block diagram of the audio driver integrated circuit provided by the utility model;
[0014] Figure 2 This is a connection diagram of the external switch of the audio driver integrated circuit provided by the utility model. DETAILED DESCRIPTION
[0015] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.
[0016] See also Figure 1 and Figure 2The utility model provides an audio driver integrated circuit, including an operational amplifier U3 and an operational amplifier U4. The non-inverting input terminal of the operational amplifier U3 is grounded through a capacitor, the non-inverting input terminal of the operational amplifier U3 is connected to the non-inverting input terminal of the operational amplifier U4, the output terminal of the operational amplifier U3 serves as a first audio output terminal VOUT1, and the output terminal of the operational amplifier U4 serves as a second audio output terminal VOUT2. The output terminal of the operational amplifier U3 is connected to the inverting input terminal of the operational amplifier U4 through a resistor R6, and the output terminal of the operational amplifier U4 is connected to its inverting input terminal through a feedback resistor R7.
[0017] The inverting input terminal of the operational amplifier U3 is used as the input terminal of the signal source. The inverting input terminal of the operational amplifier U3 is grounded through capacitor C8 and resistor C9 respectively. The inverting input terminal of the operational amplifier U3 is connected to the external input terminal through capacitor C7, resistor R18 in sequence. The output terminal of the operational amplifier U3 is connected to its inverting input terminal through resistor R17 and capacitor C6 respectively. Resistor R17 is connected in parallel with capacitor C6.
[0018] Capacitor C7 is an input coupling capacitor that isolates the DC component and prevents the DC bias voltage from entering the inverting input terminal of the operational amplifier U3, thereby protecting the circuit and allowing only AC signals to pass.
[0019] Resistor R18 is an input resistor, which is connected in series with the input signal source to limit the input current and work with the feedback network to determine the input impedance and gain of the op amp. Resistor R18 can also suppress high-frequency noise and signals and play an anti-interference role.
[0020] Resistor R17 and capacitor C6 are used in the feedback network to determine the gain and frequency response characteristics of op amp U3. At low frequencies, R17 determines the gain of op amp U3 (voltage gain is controlled by feedback). At low frequencies, capacitor C6 presents a high impedance and has little effect on the feedback resistor. At high frequencies, capacitor C6 provides a low impedance path, shorting resistor R17, thereby reducing the high frequency gain of the amplifier, improving the stability and frequency response of the circuit, and preventing high frequency oscillations.
[0021] A series voltage divider circuit is provided, including a resistor R8 and a resistor R10 connected in series, with a resistance value ranging from tens of K to 100K. A first end of the resistor R8 is connected to a power supply VDD and is grounded through a capacitor C5. A second end of the resistor R8 is connected to a first end of the resistor R10, and a second end of the resistor R10 is grounded. A common node of the resistor R8 and the resistor R10 is respectively connected to the in-phase input terminals of the operational amplifier U3 and the operational amplifier U4.
[0022] Through the synergistic effect of these components, op amp U3 is able to stably amplify signals at different frequencies, ensuring that the audio drive circuit has good frequency response and stability.
[0023] Preferably, the resistance value of the resistor R8 is equal to the resistance value of the resistor R19, and the in-phase input terminals of the operational amplifier U3 and the operational amplifier U4 obtain the VDD / 2 voltage.
[0024] A shutdown circuit is also provided, including an NPN transistor Q4, the collector of which is connected to the common node of the resistor R8 and the resistor R10, the emitter of which is grounded through the resistor R12, the base of which is connected to the switch S1 outside the integrated circuit through the resistor R11, the second end of the switch S1 is grounded, the first end of the switch S1 is connected to the resistor R11, and is connected to the power supply VDD through the pull-up resistor R13. The value of the resistor R12 is less than 100 ohms.
[0025] Resistor R12 is also connected in parallel with capacitor C3. The function of resistor R12 connected in parallel with capacitor C3 is mainly to improve the frequency response and stability of the shutdown circuit. Capacitor C3 acts as a bypass capacitor, providing a low impedance path at high frequencies to bypass high-frequency signals. Capacitor C3 exhibits low impedance at high frequencies and can bypass high-frequency noise and interference signals.
[0026] When transistor Q4 switches quickly (for example, switch S1 operates frequently), high-frequency interference signals may be generated. Capacitor C3 bypasses these high-frequency components to ground by providing a low-impedance path, thereby preventing these high-frequency signals from entering the emitter of transistor Q4 and affecting its normal operation.
[0027] Capacitor C3 helps to increase the switching speed of transistor Q4. When turning off and on transistor Q4, capacitor C3 can quickly provide or absorb current, reduce the change time of the emitter potential, and thus speed up the response speed of transistor Q4. Without capacitor C3, resistor R12 will introduce some unnecessary high-frequency noise and voltage fluctuations. Capacitor C3 is connected in parallel across R12 to stabilize the emitter voltage, reduce noise, and ensure the stability of the operating point of transistor Q4 during the switching process.
[0028] By connecting capacitor C3 in parallel, the shutdown circuit performs more stably and quickly under high frequency conditions, thereby improving the performance and reliability of the overall circuit.
[0029] Shutdown Mode:
[0030] When switch S1 is turned off, the base is pulled up to VDD through resistor R13, and transistor Q4 is in the on state. Since transistor Q4 is turned on, the common node of R8 and R10 is pulled down to the ground potential. In this way, the voltage of the in-phase input terminal of op amps U3 and U4 drops from VDD / 2 to nearly 0V, forcing the op amp to turn off the output, thereby realizing the shutdown function.
[0031] Normal working mode:
[0032] When switch S1 is closed, the base is grounded through resistor R11, and transistor Q4 is turned off. After transistor Q4 is turned off, a low impedance path is formed between the collector and the emitter, and the common node of resistors R8 and R10 is maintained at the set divided voltage VDD / 2. The in-phase input terminals of op amps U3 and U4 are both maintained at VDD / 2 voltage to ensure normal operation of the circuit.
[0033] In shutdown mode, the voltage of the non-inverting input terminal of op amps U3 and U4 is pulled down to nearly 0V, and the op amp enters a low power consumption state, greatly reducing the total power consumption of the circuit.
[0034] The circuit switch control can be achieved through a simple mechanical switch S1, which is convenient for user operation.
[0035] The shutdown function can quickly turn off the circuit when needed to avoid unnecessary current consumption, and can also protect circuit components under certain conditions (such as overload or fault).
[0036] By shutting down the circuit, the op amp can be turned off when not in use to prevent drift or temperature effects that may be caused by long-term operation, thereby enhancing the stability and reliability of the circuit.
[0037] Turning the circuit off and then back on can achieve the reset function of the circuit, which helps to reinitialize the circuit state in some cases (such as after troubleshooting).
[0038] It can be seen that the shutdown circuit realizes effective circuit switch control function through a simple NPN transistor Q4 and a small number of external components, which not only reduces power consumption and protects the circuit, but also improves the stability and reliability of the overall system. These advantages make the circuit have high practical value in audio drive applications.
[0039] This circuit uses op amps U3 and U4 to amplify and output audio signals, provides a stable reference voltage through a voltage divider circuit, and uses transistor Q4 and switch S1 to control the circuit's shutdown, making it suitable for various audio drive scenarios. Of course, switch S1 can also be an electronic switch.
[0040] The beneficial effects of implementing the utility model to provide an audio driver integrated circuit are as follows:
[0041] The audio driver circuit amplifies and outputs the audio signal through the op amps U3 and U4, provides a stable reference voltage through the voltage divider circuit, and realizes the circuit shutdown control through the transistor Q4 and the switch S1. The simple mechanical switch S1 is convenient for users to operate, and the shutdown function can quickly shut down the circuit to avoid unnecessary current consumption and protect the circuit components in the event of overload or fault. Prevent drift or temperature effects caused by long-term operation, and enhance stability and reliability. The shutdown circuit effectively reduces power consumption, improves system stability and reliability through the NPN transistor Q4 and a small number of external components, making it have high practical value in audio driver applications.
[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. An audio driver integrated circuit, comprising an operational amplifier U3 and an operational amplifier U4, wherein the output terminals of the operational amplifier U3 and the operational amplifier U4 are used to output audio signals, the in-phase input terminals of the operational amplifier U3 and the operational amplifier U4 are connected, and a series voltage divider circuit is provided to provide a reference voltage for the in-phase input terminal; the output terminal of the operational amplifier U3 is connected to the inverting input terminal of the operational amplifier U4 through a resistor R6, and the inverting input terminal of the operational amplifier U3 is used to input an audio signal, characterized in that: A shutdown circuit is also provided, including an NPN transistor Q4, the collector of which is connected to the in-phase input terminal of the operational amplifier U4, the emitter of which is grounded via a resistor R12, the base of which is connected to a switch S1 outside the integrated circuit via a resistor R11, the second end of the switch S1 being grounded; the first end of the switch S1 is connected to the resistor R11, and is connected to a power supply via a pull-up resistor R13.
2. The audio driver integrated circuit according to claim 1, characterized in that: The resistor R12 is also connected in parallel with a capacitor C3.
3. The audio driver integrated circuit according to claim 2, characterized in that: The series voltage divider circuit includes a resistor R8 and a resistor R10, a first end of the resistor R8 is connected to a power supply and is grounded through a capacitor C5, a second end of the resistor R8 is connected to a first end of the resistor R10, a second end of the resistor R10 is grounded, and a common node of the resistor R8 and the resistor R10 is respectively connected to the non-inverting input terminal of the operational amplifier U3.
4. The audio driver integrated circuit according to claim 2, characterized in that: The output terminal of the operational amplifier U3 is connected to its inverting input terminal via a resistor R17 and a capacitor C6 respectively.
5. The audio driver integrated circuit according to claim 4, characterized in that: The inverting input terminal of the operational amplifier U3 is connected to the external audio input terminal through the resistor R18 and the capacitor C7 in sequence.