External telephone communication circuit and mobile network equipment supporting external telephone

Abstract

The invention relates to the technical field of fixed-line telephone communication, in particular to an external telephone communication circuit and mobile network equipment supporting an external telephone. Comprising a boost module, a voice circuit and a digital circuit. The input end of the boosting module is used for receiving an external power supply voltage signal, and the output end of the boosting module is coupled with the input end of the voice circuit; the first communication end of the voice circuit is coupled with an external telephone set, and is used for realizing voice signal interaction between the voice circuit and the external telephone set; a charge switching unit is arranged in the voice circuit; the communication end of the digital circuit is coupled with the second communication end of the voice circuit, the digital circuit is integrated with a mobile data receiving and transmitting unit, and the charge switching unit and the control data receiving and transmitting unit are used for controlling the transmission of a flow charge channel and the selective starting of a telephone charge channel, so that the dynamic switching of charge modes is realized. The application adapts to the convenient and economical requirements of some regions on the use of the fixed-line telephone.

Description

Technical Field

[0001] The present application relates to the technical field of fixed telephone communications, and in particular to an external telephone communication circuit and a mobile network device supporting the external telephone. Background Art

[0002] Current cellular mobile network technology has achieved wide-area coverage and high-speed data transmission, but fixed-line telephone networks still occupy an important position in traditional communication scenarios. Physical landline telephones maintain their mainstream position due to their intuitive operation and stable signals.

[0003] Although existing technologies can use cellular network conversion devices such as CPE (Customer Premise Equ i pment) to convert mobile signals into voice services, such devices generally have the limitations of high price thresholds and the need for continuous external AC power supply. They are difficult to adapt to environments without stable power supply or mobile usage needs. In essence, they still cannot get rid of their dependence on fixed installation scenarios, which forms a structural contradiction with the core demands of users in backward areas for device portability, low power consumption and economy. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present application provides an external telephone communication circuit and a mobile network device that supports an external telephone. A voice circuit is added based on a more convenient and cost-effective portable rechargeable cellular mobile network device design. By switching between mobile data channels or fixed telephone channels for calls, users can choose a more suitable tariff mode according to the actual application scenario, thereby improving portability and economy.

[0005] The technical solution adopted by this application to solve its technical problems is:

[0006] In a first aspect, the present application provides an external telephone communication circuit: comprising a boost module, a voice circuit and a digital circuit;

[0007] The input end of the boost module is used to receive an external power supply voltage signal, and the output end of the boost module is coupled to the input end of the voice circuit;

[0008] The first communication end of the voice circuit is coupled to an external telephone set, and is used for the voice circuit to realize voice signal interaction with the external telephone set; the voice circuit has a built-in tariff switching unit;

[0009] The communication end of the digital circuit is coupled to the second communication end of the voice circuit. The digital circuit integrates a mobile data transceiver unit. Through the tariff switching unit, the data transceiver unit is controlled to control the transmission of the traffic tariff channel and the activation of the telephone tariff channel to realize dynamic switching of the tariff mode.

[0010] Optionally, the voice circuit includes a voice chip;

[0011] The input end of the voice chip is connected to the output end of the boost module, the first communication end of the voice chip is connected to an external telephone, and the second communication end of the voice chip is connected to the communication end of the digital circuit.

[0012] Optionally, the voice circuit further includes a radiation shielding cavity;

[0013] The radiation shielding cavity is arranged in the peripheral circuit of the voice chip to shield the outer part of the port of the voice chip as a whole, and is used to form a continuous electromagnetic shielding layer around the voice chip by physical isolation, thereby blocking the electromagnetic coupling path between the analog signal of the voice chip and the digital circuit.

[0014] Optionally, the radiation shielding cavity is made of copper alloy material.

[0015] Optionally, the boost module includes a boost circuit and a charge pump circuit;

[0016] The input end of the boost circuit receives an external power supply voltage signal, and the output end of the boost circuit is connected to the input end of the charge pump circuit;

[0017] The output end of the charge pump circuit is connected to the input end of the voice chip.

[0018] Optionally, the charge pump circuit includes a boost topology structure consisting of an NMos tube, a diode, a capacitor and an inductor;

[0019] The boost topology is configured to boost the input voltage to a voltage range of 48V to 75V;

[0020] The package size of each device meets the preset PCB layout height and area constraints.

[0021] Optionally, it is provided on a target PCB, wherein the target PCB adopts a multi-layer substrate structure;

[0022] The signal lines of the voice circuit are arranged on the first PCB layer, the signal lines of the digital circuit are arranged on the second PCB layer, and at least one isolation layer is provided between the first PCB layer and the second PCB layer.

[0023] Optionally, it further includes a clearance insulation area; the safety distance of the clearance insulation area is configured to be no less than the minimum air distance required to prevent voltage breakdown;

[0024] The clearance insulation area is arranged between the signal wiring of the voice circuit and the signal wiring of the digital circuit.

[0025] Optionally, the external telephone is an RJ11 telephone.

[0026] In a second aspect, the present application provides a mobile network device that supports an external telephone and is equipped with the above-mentioned external telephone communication circuit.

[0027] The beneficial effects of this application are as follows: the boost module boosts the external power supply voltage signal to the standard voltage required for circuit operation, ensuring normal circuit operation. The voice circuit is responsible for interacting with the external telephone for voice signals and has a built-in tariff switching unit to switch between different tariff modes. The digital circuit integrates a mobile data transceiver unit. The received tariff switching command controls the data transceiver unit to select either the data rate channel or the phone rate channel, thereby achieving dynamic tariff mode switching.

[0028] The working principle of this circuit is as follows: the boost module provides a stable operating voltage, the voice circuit connects to an external telephone to interact with voice signals and controls the circuit's tariff mode through the internal tariff switching unit, and the mobile data transceiver unit in the digital circuit transmits and receives data according to the selected tariff mode, thereby realizing seamless switching of landline numbers in a mobile network environment, providing an efficient and convenient user experience, and meeting users' needs for device portability, low power consumption, and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a first block diagram of an external telephone communication circuit provided by an embodiment of the present application;

[0030] Figure 2 This is a second block diagram of the external telephone communication circuit provided in an embodiment of the present application;

[0031] Figure 3 This is a circuit schematic diagram of a boost circuit for an external telephone communication circuit provided in an embodiment of the present application;

[0032] Figure 4 This is a circuit schematic diagram of the voice interface circuit of the external telephone communication circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] The present application is further described below with reference to the accompanying drawings and examples.

[0034] The following will clearly and completely describe the concept, specific structure and technical effects of this application in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components, but refer to the formation of a better connection structure by adding or reducing connection accessories according to the specific implementation situation. The various technical features created in this application can be combined interactively without conflicting with each other.

[0035] Reference Figure 1 , Figure 1 This is the first block diagram of the external telephone communication circuit provided by the embodiment of the present application. It shows a schematic block diagram of the interaction between the boost module, voice circuit, digital circuit involved in the circuit provided by the present application, and a telephone connected to the circuit designed in the present application. The following is a detailed description:

[0036] The input end of the boost module is used to receive an external power supply voltage signal, and the output end of the boost module is coupled to the input end of the voice circuit.

[0037] Specifically, the boost module establishes an electrical connection with the external input source through its input end, and uses a two-stage boost topology to gradually increase the initial voltage to the target value in the voltage range of 48V to 75V. This output level accurately matches the operating voltage requirement of the voice circuit, forming a complete power supply chain.

[0038] The first communication end of the voice circuit is coupled to an external telephone set, so as to realize voice signal interaction between the voice circuit and the external telephone set;

[0039] Wherein, the voice circuit has a built-in tariff switching unit.

[0040] Specifically, the voice circuit is coupled to and interacts with an external telephone. In the telephone rate model, voice signals are primarily transmitted over the traditional telephone network. Specifically, voice signals are transmitted directly to the other party's phone via the traditional telephone network. The entire process does not involve extensive digital processing of the voice signal by digital circuits or traffic-based network transmission. In this model, billing is based on telephone rate standards such as call duration and call distance (e.g., long-distance, local), rather than data consumption. For example, local calls are charged by the minute, while long-distance calls are charged according to their long-distance call rate and duration.

[0041] The communication end of the digital circuit is coupled to the second communication end of the voice circuit. The digital circuit integrates a mobile data transceiver unit. Through the tariff switching unit, the data transceiver unit is controlled to control the transmission of the traffic tariff channel and the activation of the telephone tariff channel to realize dynamic switching of the tariff mode.

[0042] Specifically, in the traffic tariff mode, the voice signal is first processed by the voice circuit, which converts the analog voice signal into a digital signal. These digital signals are then transmitted to the digital circuit, which performs further digital processing operations such as encoding and compression to make them suitable for transmission in traffic-based networks (such as mobile data networks or broadband networks). The processed digital signal is transmitted through the network in the form of a data packet. This process consumes a certain amount of network traffic, which is charged according to the traffic tariff standard. For example, if a mobile data network is used, the consumed traffic will be calculated based on the size and number of data packets sent and received, and will be charged according to the corresponding traffic package price. Finally, the digital signal is restored to a voice signal that can be recognized by the phone after corresponding decoding, decompression and other processing, and is finally played out through the phone.

[0043] In addition, the power boosted by the boost module is filtered and stabilized before being injected into the voice circuit power supply network, and then transmits the working current to the external telephone terminal through the RJ11 interface. The external telephone described in the embodiment of the application is an RJ11 telephone.

[0044] Further, refer to Figure 2 , Figure 2 This is a second block diagram of the external telephone communication circuit provided in an embodiment of the present application. Figure 2 Further demonstrated Figure 1 The specific design ideas in the block diagram are described below:

[0045] Regarding the voice circuit, in the embodiment of the present application, the voice circuit includes a voice chip;

[0046] The input end of the voice chip is connected to the output end of the boost module, the first communication end of the voice chip is connected to an external telephone, and the second communication end of the voice chip is connected to the communication end of the digital circuit.

[0047] Specifically, the core component of the voice circuit is a voice chip, whose input end is directly connected to the output end of the boost module to achieve stable transmission of high-voltage signals. In one possible embodiment, the core component of the voice circuit is a voice chip, whose input end is directly connected to the output end of the boost module to achieve stable transmission of high-voltage signals. More specifically, the first communication end of the voice chip is connected to an external telephone via an RJ11 standard interface, supporting the transmission and ringing control of analog voice signals. This interface can adopt a differential signal wiring design to effectively suppress common-mode noise in long-distance transmission to adapt to the line loss environment in remote areas.

[0048] More specifically, the second communication terminal of the voice chip is connected to the communication terminal of the digital circuit via an SPI or I2C bus, enabling bidirectional interaction between voice data and cellular network data. For example, in one possible implementation, the digital circuit encapsulates voice data into IP packets using the VoLTE protocol and transmits them over the cellular network, bypassing the high-cost links of the traditional PSTN network.

[0049] More specifically, refer to Figure 3 , Figure 3 This is a circuit schematic diagram of the boost circuit of the external telephone communication circuit provided in an embodiment of the present application. It specifically shows the specific components involved in the boost circuit, including the input terminal V_SYS, which receives the external input terminal (3.5 to 4.2V voltage input) with a current of 1.5A on the PCB, and after completing the boost through the 12V boost chip L2, transmits the signal to the charge pump circuit through its output terminal VCC12V0_SL IC.

[0050] In the embodiments of the present application, considering that if the analog signal of the voice circuit is coupled to the data line of the digital circuit through the electric field or magnetic field, it may cause communication errors or functional abnormalities, and because the electromagnetic radiation generated by the high-frequency switching power supply (such as the charge pump in the boost module) may exceed the regulatory limit, it may cause the device to fail the electromagnetic compatibility test, the embodiments of the present application further propose:

[0051] The voice circuit further includes a radiation shielding cavity; wherein the radiation shielding cavity is made of copper alloy material.

[0052] The radiation shielding cavity is arranged in the peripheral circuit of the voice chip to shield the outer part of the port of the voice chip as a whole, and is used to form a continuous electromagnetic shielding layer around the voice chip by physical isolation, thereby blocking the electromagnetic coupling path between the analog signal of the voice chip and the digital circuit.

[0053] Specifically, the voice chip and its peripheral circuits (such as the boost module and filter capacitor) are completely wrapped in a copper alloy shielding cavity, leaving only the physical opening of the RJ11 interface (needed to be connected to the telephone) and other necessary ports. The high conductivity of copper alloy can reflect / absorb electromagnetic waves, preventing the high-frequency noise of the voice circuit from radiating outward or coupling to the digital circuit.

[0054] More specifically, refer to Figure 4 , Figure 4 This is a circuit schematic diagram of the voice interface circuit of the external telephone communication circuit provided in an embodiment of the present application. It shows the connection circuit between the voice circuit and the RJ11 interface, and is equipped with an EMC chip to filter out interference.

[0055] Furthermore, in order to meet the convenience requirements and reduce the circuit footprint to make the device compact, a compact PCB layout is required. Therefore, in the embodiment of the present application, in order to avoid interlayer discharge or signal crosstalk between the high-voltage area (voice circuit part) and the low-voltage area (digital circuit part), the present application proposes to appropriately adjust the PCB layer based on the mobile network device. Specifically:

[0056] The embodiment of the present application is provided on a target PCB, wherein the target PCB adopts a multi-layer substrate structure;

[0057] The signal lines of the voice circuit are arranged on the first PCB layer, the signal lines of the digital circuit are arranged on the second PCB layer, and at least one isolation layer is provided between the first PCB layer and the second PCB layer.

[0058] Specifically, since an increase in the number of PCB layers is usually accompanied by an increase in cost, mobile network devices generally control the number of layers to 4 to 6, usually 4, for cost control reasons.

[0059] However, since this solution adds voice circuitry to the mobile network device, there's no guarantee that the voice circuit signal traces and the low-voltage traces of the digital circuitry will not discharge and interfere with the low-voltage data signals on adjacent layers due to the high-voltage signals between layers. Therefore, the voice circuit traces are placed on the first PCB layer, and the digital circuit traces on the second PCB layer. At least one GND layer (i.e., isolation layer) is placed between the first and second PCB layers. The isolation layer is an independent ground plane. It's worth noting that the voice circuit signal traces also include the signal traces involved in the boost module.

[0060] Furthermore, in order to further solve the signal isolation and interference problems caused by the high-voltage power supply of the voice circuit, in the embodiment of the present application, the PCB is adjusted by increasing the safe insulation distance of the clearance. Specifically:

[0061] The embodiment of the present application further includes a clearance insulation area; the safety distance of the clearance insulation area is configured to be no less than the minimum air distance required to prevent voltage breakdown;

[0062] The clearance insulation area is arranged between the signal wiring of the voice circuit and the signal wiring of the digital circuit.

[0063] Specifically, an appropriate distance of clearance insulation is added between the voice circuit and the digital circuit to ensure that the high-voltage signal in the voice circuit does not directly creep and discharge through the surrounding grounding. It is worth noting that if the distance of the clearance insulation area is too small, the high-voltage signal of the voice circuit may interfere with or even damage the low-voltage digital signal in the digital circuit. If the distance of the clearance insulation area is too large, the PCB area will be too large and there will be too much redundancy, making it difficult for the mobile network device to meet the requirements of miniaturization and convenient portability. Therefore, in the embodiment of the present application, a feasible implementation method is further provided, namely, setting an air gap of 1.2 mm for every 100V to prevent high voltage from breaking down through the air dielectric.

[0064] Furthermore, regarding the boost module, in the embodiment of the present application, the boost module includes a boost circuit and a charge pump circuit;

[0065] The input end of the boost circuit receives an external power supply voltage signal, and the output end of the boost circuit is connected to the input end of the charge pump circuit;

[0066] The output end of the charge pump circuit is connected to the input end of the voice chip.

[0067] Specifically, the boost module consists of a two-stage topology consisting of a boost circuit and a charge pump circuit. Its core function is to gradually boost the external low-voltage power supply (3.3V to 5V) to the high-voltage signal in the 48V to 75V range required by the RJ11 telephone interface. Specifically, the input power supply voltage signal is the input power supply for the digital circuit and the boost module, and in this embodiment of the application, it is a 3.3V input.

[0068] More specifically, for cost considerations, the boost module is equipped with a two-stage boost, including a boost circuit (first-stage boost) and a charge pump circuit (second-stage boost). In the embodiment of the present application, a 12V boost chip is provided in the boost circuit. It adopts a DC-DC converter architecture, and achieves the first-stage boost through inductive energy storage and switch tube control, raising the input voltage to a 12V intermediate voltage, providing basic power supply for the charge pump circuit. The charge pump circuit is based on the principle of capacitor charging and discharging. Through multi-stage charge transfer and voltage superposition, it periodically charges and discharges to boost the 12V intermediate voltage to a voltage range of 48V to 75V, meeting the high-voltage power supply requirements of traditional telephones and voice circuits.

[0069] More specifically, prior to this application, voice circuits were typically installed in large devices such as CPEs, which have large layout and wiring areas and almost no restrictions on device height. However, the solution proposed in the embodiments of this application requires compressing the layout and wiring area and device height to ensure the compactness and convenience of the improved circuit. Therefore, the embodiments of this application propose:

[0070] The charge pump circuit includes a boost topology structure consisting of an NMos tube, a diode, a capacitor and an inductor;

[0071] The boost topology is configured to boost the input voltage to a voltage range of 48V to 75V;

[0072] The package size of each device meets the preset PCB layout height and area constraints.

[0073] Wherein, the NMos tube is a high-pressure NMos tube.

[0074] Specifically, because the digital circuits typically used in mobile network devices have a voltage threshold of around 5V, and the voice circuits need to support the high voltage requirements of the RJ11 interface of traditional telephones (such as a 48V ringing voltage), their components (such as capacitors and diodes in the charge pump circuit) generally have a voltage withstand requirement of 20 to 50V. Some key components (such as the switching tubes in the boost module) need to withstand instantaneous peak voltages of 100 to 200V to cope with surges or voltage fluctuations. Therefore, in the embodiments of the present application, it is necessary to ensure miniaturization and performance through device selection, and to free up space on the PCB for the voice circuit by removing redundant modules (such as unused GPIO interfaces) from the original digital circuits.

[0075] More specifically, in the embodiment of the present application, the contradiction between high voltage demand and compact layout can be resolved by selecting high-voltage, low-capacitance multilayer ceramic capacitors (such as capacitors with a voltage resistance of 50V and a package of 0402) and Schottky diodes (such as diodes with a voltage resistance of 200V and a package of SOD-323).

[0076] In a second aspect, the present application provides a mobile network device that supports an external telephone and is equipped with the above-mentioned external telephone communication circuit.

[0077] The above is a specific description of the preferred implementation of the present application, but the invention of the present application is not limited to the described embodiments. Technical personnel familiar with the art can also make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. An external telephone communication circuit, characterized in that: Including boost module, voice circuit and digital circuit; The input end of the boost module is used to receive an external power supply voltage signal, and the output end of the boost module is coupled to the input end of the voice circuit; The first communication end of the voice circuit is coupled to an external telephone set, and is used for the voice circuit to realize voice signal interaction with the external telephone set; the voice circuit has a built-in tariff switching unit; The communication end of the digital circuit is coupled to the second communication end of the voice circuit. The digital circuit integrates a mobile data transceiver unit. Through the tariff switching unit, the data transceiver unit is controlled to control the transmission of the traffic tariff channel and the activation of the telephone tariff channel to realize dynamic switching of the tariff mode.

2. The external telephone communication circuit according to claim 1, characterized in that: The voice circuit includes a voice chip; The input end of the voice chip is connected to the output end of the boost module, the first communication end of the voice chip is connected to an external telephone, and the second communication end of the voice chip is connected to the communication end of the digital circuit.

3. The external telephone communication circuit according to claim 2, characterized in that: The voice circuit further includes a radiation shielding cavity; The radiation shielding cavity is arranged in the peripheral circuit of the voice chip to shield the outer part of the port of the voice chip as a whole, and is used to form a continuous electromagnetic shielding layer around the voice chip by physical isolation, thereby blocking the electromagnetic coupling path between the analog signal of the voice chip and the digital circuit.

4. The external telephone communication circuit according to claim 3, characterized in that: The radiation shielding cavity is made of copper alloy material.

5. The external telephone communication circuit according to claim 2, characterized in that: The boost module includes a boost circuit and a charge pump circuit; The input end of the boost circuit receives an external power supply voltage signal, and the output end of the boost circuit is connected to the input end of the charge pump circuit; The output end of the charge pump circuit is connected to the input end of the voice chip.

6. The external telephone communication circuit according to claim 5, characterized in that: The charge pump circuit includes a boost topology structure consisting of an NMos tube, a diode, a capacitor and an inductor; The boost topology is configured to boost the input voltage to a voltage range of 48V to 75V; The package size of each device meets the preset PCB layout height and area constraints.

7. The external telephone communication circuit according to claim 5, characterized in that: Set on a target PCB, the target PCB adopts a multi-layer substrate structure; The signal lines of the voice circuit are arranged on the first PCB layer, the signal lines of the digital circuit are arranged on the second PCB layer, and at least one isolation layer is provided between the first PCB layer and the second PCB layer.

8. The external telephone communication circuit according to claim 7, characterized in that: It also includes a clearance insulation area; the safety distance of the clearance insulation area is configured to be no less than the minimum air distance required to prevent voltage breakdown; The clearance insulation area is arranged between the signal wiring of the voice circuit and the signal wiring of the digital circuit.

9. The external telephone communication circuit according to claim 1, characterized in that: The external telephone is an RJ11 telephone.

10. A mobile network device supporting an external telephone, characterized in that: The device is equipped with an external telephone communication circuit as described in any one of claims 1 to 9.

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