TWI521878B - Inductive digital isolation circuit - Google Patents

Description

Inductive digital isolation circuit

The invention relates to an inductive digital isolation circuit, in particular to an inductive digital isolation circuit in which an inductive isolation module isolates two ends of a power supply system and can input signals bidirectionally.

In general, advances in technology have made people's lives more convenient. For example, electronic devices such as desktop computers, notebook computers, tablets, or smart phones have made people's lives and networks inseparable. Among them, the above-mentioned electronic devices generally need to use an isolation circuit for electrical isolation to protect some electronic components, so that the electronic device can operate normally, and most of the commonly used isolation circuits are optical, inductive, and capacitive. And RF type isolation circuit.

In the above circuit for separating by light, please refer to the first figure. The first figure shows the circuit diagram of the optical isolation circuit of the prior art of the present invention. As shown in the first figure, the optical isolation circuit PA1 is implemented by using a transparent insulating isolation layer. Optical transmission to achieve optical isolation, which mainly includes an input terminal PA11, an optical coupler PA12 and an output terminal PA13, wherein the optical coupler PA12 is electrically connected to the input terminal PA11 and the output terminal PA13, and includes a light. The transmitter PA121 and a photodetector PA122. Light emitter The PA121 is generally a Light-Emitting Diode (LED), which converts a digital signal input from the input terminal PA11 from an electrical signal into an optical signal, and then transmits the optical signal through the isolation layer, and then detects the light. The device PA122 (for example, a photo-thyristor, a photodiode, a photo-electric crystal) converts the optical signal back into an electrical signal so that the output terminal PA13 can receive the same signal as the input terminal PA11.

However, the operating frequency (transmission rate) of the optical isolation circuit PA1 is limited by the slower transmission characteristics of the optical transmitter PA121 (generally only up to 100 kHz), and thus cannot be commonly used in existing electronic products, and When the use time is lengthened, the efficiency of the light emitter PA121 will decrease accordingly, so that it is necessary to increase the signal drive current (generally 10 mA or more) and waste power (large power consumption), and the current and the current can be passed. The applied voltage is also limited and therefore not suitable for large power control.

In addition, for the inductive isolation circuit, please refer to the second figure. The second figure shows a block diagram of the inductive isolation circuit of the prior art of the present invention. As shown in the second figure, the inductive isolation circuit PA2 generally includes a The input terminal PA21, a modulator PA22, an oscillator PA23, an isolation layer PA24, a demodulator PA25 and an output terminal PA26, the modulator PA22 is via an operational amplifier (OP) (not shown) It is electrically connected to the input terminal PA21 and electrically connected to the oscillator PA23, and is connected to the demodulator PA25 via the isolation layer PA24, and the demodulator PA25 is electrically connected to the output terminal PA26. Among them, since the prior art generally uses the modulator PA22 and the demodulator PA25 for signal modulation and demodulation, the circuit volume is increased, so that the electronic product cannot develop toward a thin and light trend, and at the same time, manufacturing. The cost increase is plagued.

In addition, for the capacitive isolation circuit, the difference from the inductive isolation circuit PA2 is that the isolation layer PA24 in the inductive isolation circuit PA2 is composed of an inductor, and the capacitive isolation circuit is composed of a capacitor, however, due to capacitive isolation The disadvantage of the method is that there is no differential signal, that is, the input signal and the noise will share the same channel, which will cause the output signal to have some noise, and even need to use filters to filter, resulting in increased circuit size and manufacturing cost. Troubled. Therefore, the prior art still has room for improvement.

In view of the existing isolation circuits, there are generally problems of high manufacturing cost, large power consumption (power consumption), and large circuit size. Therefore, the present invention mainly provides an inductive digital isolation circuit, which mainly replaces the modulator with a switch module, thereby achieving the purpose of saving power, reducing circuit volume and manufacturing cost.

Based on the above object, the main technical means adopted by the present invention provides an inductive digital isolation circuit applied to a power supply system, and the two ends of the power system have the same signal waveform, and includes a bidirectional switching module. a first transmission module and a second transmission module. The bidirectional switching module has a first transmitting end, and the first transmitting end is configured to receive and transmit a first digital input signal. The first transmission module includes a first switch module, a first oscillating module, a first inductive isolation module, and a second switch module. The first switch module is electrically connected to the bidirectional switching module, and is configured to receive the first digital input signal, thereby determining the first opening The off module is one of a first on state and a first off state. The first oscillating module is electrically connected to the bidirectional switching module, and generates and transmits a first digital oscillating signal having the same waveform as the first digital input signal according to the first digital input signal. The first inductive isolation module is electrically connected to the first oscillation module and the first switch module for isolating the two ends of the power system, and is configured to receive the first digital input signal and the first digital oscillation signal, thereby generating And transmitting the first digital modulation signal. The second switch module has a second transmission end and is electrically connected to the first inductive isolation module for receiving the first digital modulation signal, so that the first switch module is in the first conduction state, so that The second switch module is switched to the second conductive state, and the first switch module is in the first off state, so that the second switch module is switched to the second off state, so that the second transmission end generates the first Digital modulation signal. The second transmission module is electrically connected to the bidirectional switching module and the second switching module, and is configured to generate a waveform and a second digit input signal when the second transmission end receives a second digit input signal One of the same second digit modulation signals. The bidirectional switching module is configured to switch to one of the first transmission module and the second transmission module according to the first digital input signal and the second digital input signal.

In a preferred embodiment of the above-mentioned inductive digital isolation circuit, the second transmission module includes a third switch module, a second oscillation module, a second inductive isolation module, and a first a fourth switch module electrically connected to the second transmission end for receiving the second digital input signal, thereby determining that the third switch module is in the third conduction state and the third shutdown state One. The second oscillating module is electrically Connected to the second transmission end, and according to the second digital input signal, generate and transmit a second digital oscillating signal having the same waveform as the second digital input signal; the second inductive isolation module is electrically connected to the second oscillating mode The group and the third switch module are configured to isolate the two ends of the power system, and are configured to receive the second digit input signal and the second digit oscillation signal, thereby sensing and transmitting the second digit modulation signal. The fourth switch module is electrically connected to the second inductive isolation module and the bidirectional switching module for receiving the second digital modulation signal, so that the third switch module is in the third conduction state, so that the fourth switch The module is switched to the fourth conduction state, and the third switch module is in the third off state, so that the fourth switch module is switched to a fourth off state, so that the first transmission end generates the second digit adjustment. Change the signal.

In a preferred embodiment of the above-mentioned inductive digital isolation circuit, the bidirectional switching module is composed of a first diode and a second diode, and the first two-pole system is electrically connected to The first switch module and the fourth switch module are electrically connected to the first diode. In addition, the first oscillating module and the second oscillating module are one of an oscillator and a baseband generator, and the first switch module and the third switch module are a metal oxide semiconductor field effect a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) switch, the second switch module is electrically connected to the first bipolar junction by a first Bipolar Junction Transistor (BJT) The third bipolar body is composed of one of the transistors, the first bipolar junction electro-crystal system is electrically connected to the first inductive isolation module, and the third bipolar system is electrically connected to the second transmission end, and the fourth switch mold The second bipolar junction transistor is electrically connected to the fourth bipolar body of the first bipolar junction transistor, and the second bipolar junction electromorphic system is electrically connected to the bidirectional switch. The module, the fourth diode system is electrically connected to the second inductive isolation module. In addition, the first inductive isolation module and the second inductive isolation module are a transformer.

The preferred embodiment of the inductive digital isolation circuit further includes a fifth switch module, a third inductive isolation module and a sixth switch module, and the fifth switch module The third transmission end is configured to receive a third digit input signal, thereby determining that the fifth switch module is one of a fifth conduction state and a fifth shutdown state. The third inductive isolation module is electrically connected to the fifth switch module for receiving and transmitting the third digital input signal. The sixth switch module has a fourth transmission end electrically connected to the first oscillating module and the third inductive isolation module for receiving the third digital input signal, so that the fourth transmitting end transmits the third Digital input signal. In addition, the fifth switch module is a metal oxide semiconductor field effect transistor switch, and the sixth switch module is electrically connected to the third bipolar junction transistor by a third bipolar junction transistor. The fifth bipolar body is electrically connected to the fourth transmission end, and the fifth two-pole system is electrically connected to the third inductive isolation module, and the third inductive isolation mold The group is a transformer.

After the main technical means of the inductive digital isolation circuit used in the present invention, the switch module is switched on or off according to the input signal, so that the oscillation module is turned on or off according to the switching module. , without using a modulator and demodulator and using only a few Under the cause of electronic components, the manufacturing cost and the circuit volume can be greatly reduced, and the inductive digital isolation circuit is completely ineffective in the state in which the switch module is turned off, thereby achieving the power saving effect.

The specific embodiments of the present invention will be further described by the following examples and drawings.

PA1‧‧‧ optical isolation circuit

PA11‧‧‧ input

PA12‧‧‧Optocoupler

PA121‧‧‧Light emitter

PA122‧‧‧Photodetector

PA13‧‧‧ output

PA2‧‧‧Inductive isolation circuit

PA21‧‧‧ input

PA22‧‧‧ modulator

PA23‧‧‧Oscillator

PA24‧‧‧ isolation layer

PA25‧‧‧ demodulator

PA26‧‧‧ output

1‧‧‧Inductive digital isolation circuit

11‧‧‧Two-way switching module

111‧‧‧First transmission end

112‧‧‧First Diode

113‧‧‧second diode

12‧‧‧First transmission module

121‧‧‧First switch module

122‧‧‧First Oscillation Module

123‧‧‧First Inductive Isolation Module

124‧‧‧Second switch module

1241‧‧‧second transmission end

1242‧‧‧First BJT

1243‧‧‧ Third Dipole

13‧‧‧Second transmission module

131‧‧‧Third switch module

132‧‧‧Second Oscillation Module

133‧‧‧Second inductive isolation module

134‧‧‧fourth switch module

1341‧‧‧Fourth dipole

1342‧‧‧Second BJT

14‧‧‧ fifth switch module

141‧‧‧ third transmission end

15‧‧‧Three Inductive Isolation Module

16‧‧‧ sixth switch module

161‧‧‧fourth transmission end

162‧‧‧ Third BJT

163‧‧‧ fifth diode

100,200‧‧‧RC filter circuit

S1‧‧‧ first digit input signal

S2‧‧‧ first digital oscillating signal

S3‧‧‧ first digit modulation signal

S4‧‧‧ second digit input signal

S5‧‧‧ second digital oscillation signal

S6‧‧‧ second digit modulation signal

S7‧‧‧ third digit input signal

The first figure shows a circuit diagram of an optical isolation circuit of the prior art of the present invention; the second figure shows a block diagram of an inductive isolation circuit of the prior art of the present invention; and the third figure shows an inductive digital position of a preferred embodiment of the present invention. A block diagram of an isolation circuit; and a fourth diagram showing a circuit diagram of an inductive digital isolation circuit in accordance with a preferred embodiment of the present invention.

Since the inductive digital isolation circuit provided by the present invention has a combination of implementations, it will not be repeated here, and only a preferred embodiment will be specifically described.

Please refer to the third and fourth figures. The third figure shows a block diagram of an inductive digital isolation circuit according to a preferred embodiment of the present invention. The fourth figure shows an inductive digital isolation circuit according to a preferred embodiment of the present invention. Schematic diagram of the circuit. As shown in the figure, the inductive digital isolation circuit 1 provided by the present invention is applied to a power supply system (not shown) and enables the power supply system. The second end has the same signal waveform. Specifically, the power system is, for example, a power module in an electronic device of a desktop computer, a notebook computer, a tablet computer, and a smart phone, that is, an inductive digital isolation circuit 1 It can prevent parts inside the electronic device from being damaged by voltage (for example, 110V).

The inductive digital isolation circuit 1 includes a bidirectional switching module 11 , a first transmission module 12 , a second transmission module 13 , a fifth switch module 14 , and a third inductive isolation module 15 . A sixth switch module 16.

The bidirectional switching module 11 has a first transmitting end 111. Specifically, the bidirectional switching module 11 is composed of a first diode 112 and a second diode 113, and the first diode 112 is One end of the second diode 113 is electrically connected to the first transmission end 111 and electrically connected to each other (that is, a portion of the first diode 112 electrically connected to one end of the second diode 113) It is the first transmission end 111).

The first transmission module 12 is electrically connected to the bidirectional switching module 11 and includes a first switch module 121, a first oscillating module 122, a first inductive isolation module 123 and a second switch module. Group 124. The first switch module 121 is electrically connected to the bidirectional switching module 11 . Specifically, the first switch module 121 is a metal-oxide semiconductor field effect transistor (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET). a switch, and is electrically connected to the bidirectional switching module 11 via a resistor (not shown), and electrically connected to the first transmitting end 111 via another resistor, and electrically connected to the voltage source (not shown) . In addition, it is need to be mentioned herein that the preferred embodiment of the present invention "Electrical connection" includes direct connection or indirect connection through active or passive components, and the preferred embodiment of the present invention summarizes only the above two conditions by the term "electrical connection", and is hereby described.

The first oscillating module 122 is electrically connected to the bidirectional switching module 11, specifically, it can be an oscillator or a fundamental frequency generator. If it is an oscillator, it is electrically connected by a capacitor and a bipolar junction. The Bipolar Junction Transistor (BJT) is composed of a BJT. Of course, the BJT can also be replaced by a MOSFET. The capacitor is designed according to the practical situation. Further, the capacitor is electrically connected to the bidirectional switching module 11 via the resistor and the RC filter circuit 100. One end of the BJT (collector) is electrically connected to the capacitor, and the other end (emitter) is grounded. In addition, when the first oscillating module 122 is a baseband generator, it can generate a baseband digital signal for the carrier.

The first inductive isolation module 123 is electrically connected to the first oscillation module 122 and the first switch module 121, and the first inductive isolation module 123 is a transformer, thereby isolating the two ends of the power system (for example For the electronic component end and the power supply voltage terminal). Specifically, the primary side coil of the first inductive isolation module 123 is composed of two sets of inductors (not shown), one set of inductors is electrically connected to the capacitor of the first oscillation module 122, and the other set of inductors. Then electrically connected to the base of the first switch module 121 and the first oscillation module 122.

The second switch module 124 has a second transmission end 1241 and is electrically connected to the first inductive isolation module 123. Specifically, the second switch module 124 is formed by the first BJT 1242 and the third diode. 1243, the first BJT1242 is electrically connected to the secondary side coil of the first inductive isolation module 123 via a diode and a resistor (not shown), and a third The diode 1243 is electrically connected to the first BJT 1242 and the second transmission end 1241 (more precisely, one end of the third diode 1243 is the second transmission end 1241), and is electrically connected to another resistor and Another voltage source (not shown).

The second transmission module 13 is electrically connected to the bidirectional switching module 11 and the second switching module 124. Specifically, the second transmission module 13 includes a third switching module 131 and a second oscillating module 132. a second inductive isolation module 133 and a fourth switch module 134. That is, in the preferred embodiment of the present invention, the internal components of the second transmission module 13 cover the bidirectional switching module 11 Electronic component.

The third switch module 131 is electrically connected to the second transmission end 1241 of the second switch module 124 via a diode (not shown) and a resistor, and is electrically connected via a second resistor (not shown). The third switching module 131 is connected to the third diode 1243. Specifically, the third switching module 131 is a MOSFET switch, but is not limited thereto in other embodiments.

The second oscillating module 132 is indirectly electrically connected to the second transmitting end 1241 via a resistor (not shown) and the RC filter circuit 200. Specifically, the second oscillating module 132 can be an oscillator or a fundamental frequency. The generator, if it is an oscillator, is composed of a capacitor and a BJT. Of course, the BJT can also be replaced by a MOSFET, which is designed according to the practical situation. In addition, the capacitor is electrically connected to the RC filter circuit 200 via a resistor. At the second transmission end 1241, one end (collector) of the BJT is electrically connected to the capacitor, and the other end (emitter) is grounded. In addition, when the second oscillating module 132 is a baseband generator, it can generate a baseband digital signal for the carrier.

The second inductive isolation module 133 is electrically connected to the second oscillation module 132 and the third switch module 131, and the second inductive isolation module 133 is a transformer, thereby isolating the two ends of the power system. Specifically, the primary side coil of the second inductive isolation module 133 is composed of two sets of inductors (not shown), one set of inductors is electrically connected to the capacitor of the second oscillating module 132, and the other set of inductors. Then electrically connected to the bases of the diodes in the third switch module 131 and the second oscillation module 132.

The fourth switch module 134 is electrically connected to the second inductive isolation module 133 and the bidirectional switching module 11. Specifically, the fourth switch module 134 is composed of a fourth diode 1341 and a second BJT1342. One end of the fourth diode 1341 is electrically connected to the secondary side coil of the second inductive isolation module 133, and the second BJT1342 is electrically connected to the fourth diode 1341 and a resistor (base and The quadrupole body 1341 is electrically connected, the emitter is grounded, and the collector is electrically connected to the first diode 111 of the bidirectional switching module 11).

The fifth switch module 14 has a third transmission end 141. Specifically, it is a MOSFET switch. The third transmission end 141 is electrically connected to a resistor (not shown) and passed through another resistor (not shown). The RC filter circuit 200 is electrically connected to the second oscillating module 132 and the second inductive isolation module 133.

The third inductive isolation module 15 is electrically connected to the fifth switch module 14 . Specifically, the primary side coil is electrically connected to the fifth switch module 14 , the second oscillation module 132 , and the second inductor. The isolation module 133 and the third inductive isolation module 15 are a transformer.

The sixth switch module 16 has a fourth transmission end 161 and is electrically connected. In the first oscillating module 122 and the third inductive isolation module 15, specifically, the sixth switch module 16 is electrically connected to a third BJT 162 and a fifth diode 163 of the third BJT 162. The collector of the third BJT 162 is electrically connected to the fourth transmission end 161 and electrically connected to the first oscillation module 122 via the RC filter circuit 100, and the emitter of the third BJT 162 is grounded. The fifth diode 163 is electrically connected to the base of the third BJT 162 and electrically connected to the secondary side coil of the third inductive isolation module 15 .

The first transmitting end 111 is configured to receive and transmit a first digital input signal S1. The source of the first digital input signal S1 may be the digital data transmitted by the electronic component end, but the other embodiments are not limited thereto. In addition, it should be noted that the "transport end" as defined in the preferred embodiment of the present invention refers to an end portion that can input a signal and can output a signal, which is based on the design of the actual situation and is input or It is an output, which is hereby stated.

After the first digital input signal S1 is received by the first transmitting end 111, the second diode 113 is turned on, and the first switching module 121 receives the first digital input signal S1, thereby determining that the first switching module 121 is One of the first on state and the first off state (ie, turned on or off), for example, in the preferred embodiment of the present invention, when the first digital input signal S1 is 0, the first switching mode The group 121 is in an on state, and when the first digit input signal S1 is 1, the first switch module 121 is in an off state.

The first oscillating module 122 also receives the first digital input signal S1 at the same time, and further determines the guiding of the first digital input signal S1 according to the first digital input signal S1. The on state or the off state, thereby utilizing the On Off Keying (OOK) mode carrier (the carrier frequency is, for example, between 1 M and 10 MHz), thereby generating and transmitting the same waveform as the first digital input signal S1. The first digital oscillation signal S2 is transmitted to the primary side coil of the first inductive isolation module 123, and the first side coil of the first inductive isolation module 123 receives the first After the digital input signal S1 and the first digital oscillation signal S2, the secondary side coil senses and generates the first digital modulation signal S3 and transmits it to the second switching module 124.

Before the second switch module 124 receives the first digital modulation signal S3, it is operated by an integrating circuit (ie, a circuit composed of a diode and a resistor), and the second switch module 124 is in a second conductive state. One of the second off states (the third diode 1243 is also turned on and off, and specifically, the first switch module 121 is in the first conductive state, and the second switch module 124 is switched to the first a second conducting state; the first switching module 121 is in a first off state, and the second switching module 124 is switched to a second off state), so that the second transmitting end 1241 generates a first digital modulation signal S3 That is, the digital signal received by the second transmitting end 1241 is the same as the digital signal input by the first transmitting end 111.

In addition, the inductive digital isolation circuit 1 provided by the present invention has a bidirectional transmission function, which is achieved by the second transmission module 13, specifically, a second digital input is input to the second transmission end 1241. Similarly, the third switch module 131 is turned on when the second digit input signal S4 is 0, and is turned off when 1 is used, and the second oscillating module 132 also receives the second digit input signal. S4, and then According to the second digit input signal S4, the third switch module 131 is determined to be in a third conductive state or a third turned-off state, so that the carrier of the key-critical mode is utilized, and the waveform generated and transmitted is the same as the second digital input signal S4. a second digital oscillating signal S5, and the second digital oscillating signal S5 is transmitted to the primary side coil of the second inductive isolation module 133, and the first side coil of the second inductive isolation module 133 receives the first After the binary digit input signal S4 and the second digit oscillating signal S5, the secondary side coil senses and generates a corresponding second digit modulating signal S6 and transmits it to the fourth switching module 134.

Before the fourth switch module 134 receives the second digital modulation signal S6, the fourth switch module 134 is fourth conductive through an integration circuit (also a circuit composed of a diode and a resistor). One of the state and the fourth off state (the fourth diode 1341 is also turned on and off, and specifically, the third switch module 131 is in the third conduction state, and the fourth switch module 134 is switched. Is the fourth conduction state; and in the third switch module 131 is in the third off state, the fourth switch module 134 is switched to the fourth off state), so that the first transmission end 111 generates the second digit modulation Signal S6. It is worth mentioning that the first diode 112 in the bidirectional switching module 11 is used to transmit a signal when the second transmitting end 1241 inputs a digital signal, and the second diode 113 is The second transmission module 11 is configured to switch between the first transmission module 12 and the second transmission module 13 according to the first digital input signal S1. One of them), in order to prevent the two-way simultaneous conduction and lose the circuit function, is hereby described.

In addition, in addition to the above two-way function, the inductive digital isolation circuit 1 further provides another set of circuits having only one-way transmission function. Specifically, the third transmission end 141 is configured to input a third digital input signal S7, thereby determining The fifth switch module 14 is in a fifth conduction state or a fifth off state. Similarly, in the preferred embodiment of the present invention, when the third digit input signal S7 is 0, it is turned on, and when it is 1, it is turned off. When the fifth switch module 14 is turned on and off, the primary side coil of the third inductive isolation module 15 receives the third digital input signal S7, and the secondary side coil senses and transmits the third digital input signal. S7, the fifth diode 163 of the sixth switch module 16 is turned on and off to cause the fourth transmission terminal 161 to transmit the third digit input signal S7.

In summary, after the inductive digital isolation circuit used in the present invention is adopted, since the switch module is switched on or off according to the input signal, the oscillation module is turned on or off according to the switch module. The carrier signal can be used to reduce the manufacturing cost and circuit volume without using the modulator and demodulator and only a few electronic components, and the inductor module is turned off. The digital isolation circuit is completely ineffective and can achieve power saving effects.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed.

11‧‧‧Two-way switching module

111‧‧‧First transmission end

112‧‧‧First Diode

113‧‧‧second diode

121‧‧‧First switch module

122‧‧‧First Oscillation Module

123‧‧‧First Inductive Isolation Module

124‧‧‧Second switch module

1241‧‧‧second transmission end

1242‧‧‧First BJT

1243‧‧‧ Third Dipole

131‧‧‧Third switch module

132‧‧‧Second Oscillation Module

133‧‧‧Second inductive isolation module

134‧‧‧fourth switch module

1341‧‧‧Fourth dipole

1342‧‧‧Second BJT

14‧‧‧ fifth switch module

141‧‧‧ third transmission end

15‧‧‧Three Inductive Isolation Module

16‧‧‧ sixth switch module

161‧‧‧fourth transmission end

162‧‧‧ Third BJT

163‧‧‧ fifth diode

100,200‧‧‧RC filter circuit

Claims (12)

An inductive digital isolation circuit is applied to a power supply system and has the same signal waveform at two ends of the power system, including: a bidirectional switching module having a first transmission end, and the first transmission end For receiving and transmitting a first digital input signal; a first transmission module electrically connected to the bidirectional switching module, and comprising: a first switching module electrically connected to the bidirectional switching module And configured to receive the first digital input signal, thereby determining that the first switch module is in one of a first conductive state and a first turn-off state; a first oscillating module is electrically connected to The bidirectional switching module receives and transmits a first digital oscillating signal having the same waveform as the first digital input signal according to the first digital input signal; and a first inductive isolation module electrically connected to the The first oscillating module and the first switch module are configured to isolate the two ends of the power system, and are configured to receive the first digital input signal and the first digital oscillating signal, thereby sensing and transmitting a first a second modulation module, and a second transmission module electrically connected to the first inductive isolation module for receiving the first digital modulation signal, thereby a switch module is in the first conductive state, the second switch module is switched to a second conductive state, and the second switch module is switched in the first switch module. a second off state, wherein the second transmission end generates the first digital modulation signal; and a second transmission module electrically connected to the bidirectional switching module and the second a switch module, configured to: when the second transmission end receives a second digital input signal, cause the first transmission end to generate a second digital modulation signal of the same waveform as the second digital input signal; wherein the two-way The switching module is configured to switch to one of the first transmission module and the second transmission module according to the first digital input signal and the second digital input signal. The inductive digital isolation circuit of claim 1, wherein the second transmission module comprises a third switch module, a second oscillation module, a second inductive isolation module, and a first a fourth switch module electrically connected to the second transmission end for receiving the second digital input signal, thereby determining that the third switch module is in a third conductive state and a third One of the off states; the second oscillating module is electrically connected to the second transmitting end, receives and generates and transmits the same waveform as the second digital input signal according to the second digital input signal The second inductive isolation module is electrically connected to the second oscillation module and the third switch module for isolating the two ends of the power system and for receiving the second digit input The signal and the second digital oscillating signal are used to sense and transmit a second digital modulation signal; the fourth switching module is electrically connected to the second inductive isolation module and the bidirectional switching module, Receiving the second digit Changing the signal, wherein the third switch module is in the third conduction state, the fourth switch module is switched to a fourth conductive state, and the third switch module is in the third off state, so that The fourth switch module is switched to a fourth off state, so that the first transmission end generates the second digital modulation signal. The inductive digital isolation circuit of claim 2, wherein the bidirectional switching module is composed of a first diode and a second diode, and the first two-pole system is electrically connected. In the first switch module and the fourth switch module, the second diode system is electrically connected to the first diode. The inductive digital isolation circuit of claim 2, wherein the first oscillation module and the second oscillation module are one of an oscillator and a fundamental frequency generator. The inductive digital isolation circuit of claim 2, wherein the first switch module and the third switch module are a metal oxide semiconductor field effect transistor (Metal-Oxide-Semiconductor Field- Effect Transistor, MOSFET) switch. The inductive digital isolation circuit of claim 2, wherein the second switching module is electrically connected to the first bipolar junction transistor (BJT) a third bipolar body of the bipolar junction transistor, the first bipolar junction electro-crystal system is electrically connected to the first inductive isolation module, and the third dipole system is electrically connected to the The second transmission end. The inductive digital isolation circuit of claim 2, wherein the fourth switching module is electrically connected to the first bipolar junction transistor by a second bipolar junction transistor. a fourth dipole, the first The two-pole polarity contact crystal system is electrically connected to the two-way switching module, and the fourth two-pole system is electrically connected to the second inductive isolation module. The inductive digital isolation circuit of claim 2, wherein the first inductive isolation module and the second inductive isolation module are a transformer. The inductive digital isolation circuit of claim 1, further comprising a fifth switch module, a third inductive isolation module and a sixth switch module, wherein the fifth switch module is Having a third transmission end, the third transmission end is configured to receive a third digit input signal, thereby determining that the fifth switch module is in one of a fifth conduction state and a fifth off state; The third inductive isolation module is electrically connected to the fifth switch module for receiving and transmitting the third digital input signal; the sixth switch module has a fourth transmission end, and is electrically The first oscillating module and the third inductive isolation module are connected to receive the third digital input signal, so that the fourth transmitting end transmits the third digital input signal. The inductive digital isolation circuit of claim 9, wherein the fifth switch module is a metal oxide semiconductor field effect transistor switch. The inductive digital isolation circuit of claim 9, wherein the sixth switch module is electrically connected to the third bipolar junction transistor by a third bipolar junction transistor. a group of fifth diodes The third bipolar junction transistor system is electrically connected to the fourth transmission end, and the fifth diode system is electrically connected to the third inductive isolation module. The inductive digital isolation circuit of claim 9, wherein the third inductive isolation module is a transformer.