An automatic load detection and audio input source switching circuit

Abstract

The present invention discloses an automatic load detection and audio input source switching circuit, which includes a current detection unit, a switching unit, an audio amplifier, and a voltage converter. Among them, the switching unit is respectively connected to the current detection unit, the audio amplifier, and the voltage converter. The voltage converter outputs different voltages to supply power to the switching unit, the current detection unit, and the input source. The switching unit and the audio amplifier are also respectively connected to the DSP chip of the cochlear implant speech processor. The present invention can automatically detect the input source connected to the external device of the cochlear implant, and can automatically identify the FM receiver or the external direct audio input, without manual intervention, which greatly facilitates the users of cochlear implants. At the same time, low-power devices are adopted in the whole circuit, and only part of the circuit works when the whole circuit is in standby operation. After testing, the static power consumption of the whole circuit is less than 3 μA, which can extend the battery usage time.

Description

Technical Field

[0001] The invention belongs to the field of medical equipment, and in particular relates to an automatic load detection and audio input source switching circuit. Background Art

[0002] There are multiple sources of audio input for the external cochlear implant. In addition to the sound collected by the machine's own microphone, there are also electrical signals directly input from external audio, and signals received by the FM system.

[0003] Due to the input of multiple audio signals, sometimes the recipient needs to switch between multiple devices to realize the input switching of multiple audio signals, or needs to use specific interface buttons to realize the switching of multiple audio source inputs. Summary of the invention

[0004] In view of this, the present invention solves the problem of automatic switching between FM system audio signals and other audio input signals and identifies corresponding signals, amplifies the FM input signals, and directly inputs other external audio inputs to the DSP. The whole process does not require manual intervention, while reducing the standby power consumption of the entire circuit.

[0005] To achieve the above object, the present invention provides an automatic load detection and audio input source switching circuit, including a current detection unit, a switch unit, an audio amplifier and a voltage converter, wherein:

[0006] The switch part is connected to the current detection part, the audio amplifier and the voltage converter respectively, the voltage converter outputs different voltages to the switch part, the current detection part and the input source to supply power, and the switch part and the audio amplifier are also connected to the DSP chip of the cochlear implant speech processor respectively;

[0007] The switch unit includes two single-pole double-throw switches;

[0008] The current detection unit includes a current detection amplifier and a current detection resistor, and the current detection resistor detects the input source;

[0009] When no input source or load is connected, the voltage converter outputs 1.2V, the current on the current detection resistor is in the microampere level, the current detection amplifier does not work, and the output to the switch part is a low level. The switch part is in the default working state and has no output;

[0010] When the input source is an FM receiver, the voltage converter outputs a voltage to power the FM receiver, the current detection resistor detects the current, the voltage on the current detection resistor is the working voltage of the current detection amplifier, the current detection amplifier is in a working state, and the output to the switch part is a high level. The switch part outputs the signal output by the FM receiver to the audio amplifier, and the audio amplifier amplifies and filters the signal and then outputs it to the DSP chip of the cochlear implant speech processor;

[0011] When the input source is direct audio input, the current on the current detection resistor is in the microampere level, the current detection amplifier does not work, the output to the switch part is low level, the switch part is in the default working state, and the signal of the direct audio input is directly output to the DSP chip of the cochlear implant speech processor.

[0012] Preferably, it further includes an interface socket, and both the FM receiver and the direct audio input are connected to the interface socket.

[0013] Preferably, a filter capacitor C3 is connected between the audio amplifier and the DSP chip of the cochlear implant speech processor.

[0014] The beneficial effects of the present invention are as follows: The present invention realizes the automatic detection of the device connected to the cochlear connector and can automatically identify the FM receiver or the external direct audio input. For the directly external audio input, the audio signal will be directly sent to the DSP chip without any processing. When the FM receiver is connected to the J1 connector, the FM device will be detected, the signal of the FM receiver will be connected to the audio amplifier, and after the signal is amplified, it will be input to the DSP chip. The whole process does not require manual intervention, which greatly facilitates the cochlear implant users. At the same time, low-power devices are used in the whole circuit, and only part of the circuit works when the whole circuit is in standby operation. After testing, the static power consumption of the whole circuit is less than 3uA, which can extend the battery usage time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to make the objectives, technical solutions and beneficial effects of the present invention clearer, the present invention provides the following drawings for description:

[0016] Figure 1 It is a structural block diagram of the automatic load detection and audio input source switching circuit according to an embodiment of the present invention;

[0017] Figure 2 It is a circuit schematic diagram of the automatic load detection and audio input source switching circuit according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The preferred embodiments of the present invention will be described in detail below with reference to the drawings.

[0019] Refer to Figure 1 , which shows a structural block diagram of the automatic load detection and audio input source switching circuit according to an embodiment of the present invention, including a current detection unit 10, a switch unit 20, an audio amplifier 30 and a voltage converter 50, wherein,

[0020] The switch unit 20 is respectively connected to the current detection unit 10, the audio amplifier 30, and the voltage converter 50. The voltage converter 50 supplies different voltages to the switch unit 20, the current detection unit 10, and the input source for power supply. The switch unit 20 and the audio amplifier 30 are also respectively connected to the DSP chip 60 of the cochlear implant speech processor;

[0021] The switch unit 20 includes two single-pole double-throw switches;

[0022] The current detection unit 10 includes a current detection amplifier and a current detection resistor, and the current detection resistor detects the input source;

[0023] When no input source or load is connected, the voltage converter 50 outputs a voltage of 1.2V. The current on the current detection resistor is in the microampere level, the current detection amplifier does not work, and the output to the switch unit 20 is a low level. The switch unit 20 is in the default working state and has no output;

[0024] When the input source is the FM receiver 42, the voltage converter 50 outputs a voltage to supply power to the FM receiver 42. The current detection resistor detects the current, and the voltage on the current detection resistor is the working voltage of the current detection amplifier. The current detection amplifier is in the working state, and the output to the switch unit 20 is a high level. The switch unit 20 outputs the signal output by the FM receiver 42 to the audio amplifier 30, and the audio amplifier 30 performs amplification and filtering processing and then outputs to the DSP chip 60 of the cochlear implant speech processor;

[0025] When the input source is the direct audio input 41, the current on the current detection resistor is in the microampere level, the current detection amplifier does not work, and the output to the switch unit 20 is a low level. The switch unit 20 is in the default working state and directly outputs the signal of the direct audio input 41 to the DSP chip 60 of the cochlear implant speech processor.

[0026] See Figure 2 , for the circuit schematic diagram. U30 is the current detection amplifier, R2 is the current detection resistor with a resistance value of 10Ω, U1 is the voltage conversion chip in the voltage converter 50, which outputs a voltage of 1.2V. U28 are the two single-pole double-throw switch chips of the switch unit 20, U2 is the audio amplification chip in the audio amplifier 30, and J1 is the interface socket. The four pins on the interface socket are GND (ground wire), 1.2V, AUXIN (audio input pin), and AUXOUT (audio output pin). An FM receiver 42 (3 pins) or other direct audio input 41 (2 pins) can be connected to the interface socket.

[0027] The entire circuit has three working states:

[0028] a), no load is connected to the J1 interface socket;

[0029] b), an FM receiver 42 is connected to the J1 interface socket;

[0030] c), a direct audio input 41 is connected to the J1 interface socket.

[0031] a) When no load is connected to the J1 interface socket, after the entire system is powered on, U30, U28, and U1 are powered on and working. U1 outputs a 1.2V voltage. At this time, the current on R2 is very small, at the μA level, and the output of the current detection amplifier B2 pin of U30 is low level. The inputs of pins 4 and 5 (IN1, IN2) of the single-pole double-throw switch U28 are also low level. U28 is in the default working state, D1 and S1B are connected, and D2 and S2B are connected. At this time, there is no signal on the pin S1B input to the DSP.

[0032] b) When an FM receiver 42 is connected to the J1 interface socket, U1 powers the FM receiver 42. At this time, a current is detected on the R2 resistor, and the current detection amplifier of U30 detects the voltage drop on R2. The B2 pin of U30 outputs a high level. At this time, the inputs of pins 4 and 5 (IN1, IN2) of U28 are high level. D1 and S1A of U28 are connected. The voltage on the R1 resistor is close to Vbat, and U2 is in the working state. The D2 pin and S2A pin of U28 are connected. The AUXIN signal on the J1 interface socket is the signal output by the FM receiver 42. This signal is connected from D2 to S2A of U28 and enters the 3rd pin (input) of U2, amplified and then output to the 2nd pin (output) and connected to the DSP chip 60 through C3. At this time, the output signal of the FM receiver 42 is amplified by U2 and then output to the DSP chip 60. By using U30 to detect whether the FM receiver 42 is connected to the J1 interface socket, U28 automatically switches the audio signal input path and accesses the U2 audio amplification chip, and amplifies the signal of the FM receiver 42 and outputs it to the DSP chip 60.

[0033] c) When the external input source of the J1 interface socket is the direct audio input 41 signal, the load on the U1 power supply does not change, and the voltage drop on the R2 resistor also does not change. The output of the U30 current detection amplifier chip is low level. The inputs of pins 4 and 5 (IN1, IN2) of U28 are low level. At this time, D1 of U28 is connected to S1B, and U2 does not work. The D2 pin of U28 is connected to S2B. The external audio signal is directly connected from D2 to S2B and then directly enters the DSP chip 60.

[0034] The present invention

[0035] 1. Load automatic detection technology, that is, at the socket of the cochlear implant, after adding the FM receiver 42, the current detection unit 10 can automatically identify and output a high level. The current detection amplifier U30 automatically identifies whether the FM receiver 42 is added by detecting the change in current on R2. If the FM receiver 42 is added, due to the working current of the FM receiver 42, the voltage drop on R2 is amplified by U30 and a high level is output. R2 can be automatically adjusted according to the magnitude of the load current and the amplification factor of U30. Assume the current passing through R2 is I and the amplification factor of U30 is A. Then the output voltage Uout of U30 = I * R2 * A. Fixing the value of Uout, I, R2, and the amplification factor of U30 can be adjusted according to the actual situation.

[0036] 2. Automatic switching and amplification of the audio signal input source. When no load is added to the J1 interface socket or the direct audio input 41 is connected, since no load is added to U1, it is only static power consumption, and the voltage drop across the R2 resistor is very small. At this time, the voltage output by U30 to U28 is low level, and U28 is in the default working state. The D2 of U28 is directly connected to S2B, and at this time, the external audio signal can be directly input to the DSP, that is, the DSP chip 60 of the cochlear implant speech processor. When the FM receiver 42 is added to the J1 interface socket, U1 has a load, there is a voltage drop across the R2 resistor, and this voltage drop is amplified by U30 and output to U28. At this time, D1 is connected to S1A, and the U2 audio amplifier 30 starts to work. On the other path, D2 and S2A are connected, and the audio signal of the FM receiver 42 is sent to the U2 amplifier for amplification, and the amplified signal is sent to the DSP chip 60 through the blocking capacitor C3.

[0037] 3. Through the detection of the load, the audio amplifier 30U2 is selectively connected to the circuit. When the FM receiver 42 is not connected, the audio signal is directly sent to the DSP chip 60. At this time, there is no need to connect the U2 audio amplifier 30, reducing the power consumption of the circuit. When no external load is connected. The U2 audio amplifier 30 is also not connected to the circuit, reducing the standby power consumption of the whole machine. The actual test shows that the standby power consumption of the whole circuit is less than 3uA, significantly extending the standby time of the battery-powered device.

[0038] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. An automatic load detection and audio input source switching circuit, characterized by comprising a current detection part, a switching part, an audio amplifier, and a voltage converter, wherein, The switching part is respectively connected to the current detection part, the audio amplifier, and the voltage converter. The voltage converter outputs different voltages to supply power to the switching part, the current detection part, and the input source. The switching part and the audio amplifier are also respectively connected to the DSP chip of the cochlear implant speech processor; The switching part includes 2 single-pole double-throw switches; The current detection part includes a current detection amplifier and a current detection resistor, and the current detection resistor detects the input source; When no input source or load is connected, the voltage converter outputs At 1.2V voltage, the current on the current detection resistor is in the microampere level, the current detection amplifier does not work, the output to the switching part is low level, and the switching part is in the default working state with no output. When the input source is an FM receiver, the voltage converter outputs voltage to supply power to the FM receiver. The current detection resistor detects the current, and the voltage on the current detection resistor is the working voltage of the current detection amplifier. The current detection amplifier is in the working state, the output to the switching part is high level, and the switching part outputs the signal output by the FM receiver to the audio amplifier. After the audio amplifier performs amplification and filtering processing, it outputs to the DSP chip of the cochlear implant speech processor. When the input source is a direct audio input, the current on the current detection resistor is in the microampere level, the current detection amplifier does not work, the output to the switching part is low level, and the switching part is in the default working state and directly outputs the signal of the direct audio input to the DSP chip of the cochlear implant speech processor. A filter capacitor C3 is connected between the audio amplifier and the DSP chip of the cochlear implant speech processor.

2. The automatic load detection and audio input source switching circuit according to claim 1, characterized in that It further includes an interface socket, and both the FM receiver and the direct audio input are connected to the interface socket.

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