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CN-121984492-A - Digital isolator with optimized matching and application circuit thereof

CN121984492ACN 121984492 ACN121984492 ACN 121984492ACN-121984492-A

Abstract

The invention provides a digital isolator with optimized matching and an application circuit thereof.A first matching network and/or a second matching network in the digital isolator with a return function are RF transformers; the RF transformer comprises a first winding, a second winding and a third winding, wherein the first winding is connected with a corresponding signal amplifier, the second winding is connected with a corresponding antenna, and the third winding is connected with a corresponding envelope detector. Preferably, the second matching network is a second RF transformer, a first winding of the second RF transformer is connected with the second signal amplifier, a second winding is connected with the second coupling element, and a third winding is connected with the second envelope detector. The invention aims at a digital isolation circuit for realizing bidirectional communication based on a single-pair coupling transmission structure, and can realize the impedance coordination of a coupling piece, an envelope detector and a signal amplifier by configuring an RF transformer for network matching of the isolation circuit, so that signal reflection and maximum power transmission signal energy are eliminated, and meanwhile, the system performance is improved.

Inventors

  • LI CHENG
  • LI ZUOWEI

Assignees

  • 德氪微电子(深圳)有限公司

Dates

Publication Date
20260505
Application Date
20260211

Claims (14)

  1. 1. The digital isolator with optimized matching is characterized by comprising a first isolation circuit and a second isolation circuit which are respectively positioned at two sides of an isolation belt, wherein the first isolation circuit comprises a first coupling piece, a first matching network, a first envelope detector and a first signal amplifier, the second isolation circuit comprises a second coupling piece, a second matching network, a second envelope detector and a second signal amplifier, the first coupling piece, the first envelope detector and the first signal amplifier are respectively connected with the first matching network, and the second coupling piece, the second envelope detector and the second signal amplifier are respectively connected with the second matching network; the second signal amplifier is configured to modulate the received abnormal signal into a high-frequency signal and then send the high-frequency signal to the second matching network; the second matching network is configured to receive the normal signal sent by the second coupling element and send the high-frequency signal out through the second coupling element in a low-level neutral position of the normal signal; the first matching network is configured to receive the high-frequency signal sent by the first coupling element and then to couple and transmit the high-frequency signal to the first envelope detector; The first envelope detector is configured to send out prompt information if a high-frequency signal can be detected from a low-level neutral position of a coupling signal sent by the first matching network; the first matching network and/or the second matching network is an RF transformer, the RF transformer comprises a first winding, a second winding and a third winding, the first winding is connected with a corresponding signal amplifier, the second winding is connected with a corresponding antenna, and the third winding is connected with a corresponding envelope detector.
  2. 2. The optimally matched digital isolator of claim 1, wherein said second matching network is a second RF transformer, a first winding of said second RF transformer being connected to said second signal amplifier, a second winding being connected to said second coupling, and a third winding being connected to said second envelope detector.
  3. 3. The optimally matched digital isolator of claim 1, wherein the first matching network is a first RF transformer, a first winding of the first RF transformer is connected to the first signal amplifier, a second winding is connected to the first coupling, and a third winding is connected to the first envelope detector.
  4. 4. The optimally matched digital isolator of claim 1, wherein the first matching network is a first RF transformer and the second matching network is a second RF transformer; A first winding of the first RF transformer is connected to the first signal amplifier, a second winding is connected to the first coupling, and a third winding is connected to the first envelope detector; a first winding of the second RF transformer is connected to the second signal amplifier, wherein a second winding is connected to the second coupling, and wherein a third winding is connected to the second envelope detector.
  5. 5. The optimally matched digital isolator of claim 1, wherein one end of the second winding in the RF transformer is GSSG, gsgsgsg or GSG topology, and wherein signal port S connects the corresponding coupling.
  6. 6. The optimally matched digital isolator of claim 2 wherein the front end circuit of the second envelope detector is of a common gate architecture, wherein one end of the second winding of the second RF transformer is of a GSG topology, wherein the signal port S is connected to the second coupling element, wherein the output of the second signal amplifier is connected to the first winding of the second RF transformer, and wherein the source of the MOS transistor in the front end circuit of the second envelope detector is connected to the third winding of the second RF transformer.
  7. 7. The optimally matched digital isolator according to claim 2, wherein a front-end circuit of the second envelope detector adopts a common-gate architecture, one end of a second winding of the second RF transformer adopts a GSSG or gsgsgsg layout mode, two signal ports S therein are connected with the second coupling member, an output end of the second signal amplifier is connected with a first winding of the second RF transformer, and a source electrode of a MOS tube in the front-end circuit of the second envelope detector is connected with a third winding of the second RF transformer.
  8. 8. The optimally matched digital isolator of claim 6 or 7, wherein a capacitor is connected between the source of one MOS transistor and the gate of the other MOS transistor in the front-end circuit of the second envelope detector.
  9. 9. The optimally matched digital isolator of claim 3 wherein the front end circuit of the first envelope detector is of a common gate architecture, wherein one end of the second winding of the first RF transformer is of a GSG topology, wherein the signal port S is connected to the first coupling, wherein the output of the first signal amplifier is connected to the first winding of the first RF transformer, and wherein the source of the MOS transistor in the front end circuit of the first envelope detector is connected to the third winding of the first RF transformer.
  10. 10. The optimally matched digital isolator of claim 3 wherein the front end circuit of the first envelope detector is of a common gate architecture, one end of the second winding of the first RF transformer is of a GSSG or gsgsgsg topology, two signal ports S therein are connected to the first coupling, the output of the first signal amplifier is connected to the first winding of the first RF transformer, and the source of the MOS transistor in the front end circuit of the first envelope detector is connected to the third winding of the first RF transformer.
  11. 11. The optimally matched digital isolator of claim 9 or 10, wherein a capacitance is connected between the source and gate in the front-end circuit of the first envelope detector.
  12. 12. The optimally matched digital isolator of claim 1 wherein said first isolation circuit is a first millimeter wave isolation circuit, said second isolation circuit is a second millimeter wave isolation circuit, said first coupling is a first millimeter wave antenna, and said second coupling is a second millimeter wave antenna.
  13. 13. The optimally matched digital isolator of claim 1, wherein the first isolation circuit is a first magnetic coupling isolation circuit or a first capacitive coupling isolation circuit, the second isolation circuit is a second magnetic coupling isolation circuit or a second capacitive coupling isolation circuit, the first coupling is a first magnetic coupling or a first capacitive coupling, and the second coupling is a second magnetic coupling or a second capacitive coupling.
  14. 14. An application circuit of the optimally matched digital wave isolator is characterized by comprising the optimally matched digital wave isolator as claimed in any one of the claims 1 to 13, a first isolated circuit and a second isolated circuit; The first isolated circuit is connected with the first isolated circuit, and the second isolated circuit is connected with the second isolated circuit.

Description

Digital isolator with optimized matching and application circuit thereof Technical Field The invention relates to the technical field of isolators, in particular to a digital isolator for optimizing matching and an application circuit thereof. Background In the digital isolator with backhaul function, as shown in fig. 1, a transmitting end (TX)/receiving end (RX) mainly includes components such as a signal amplifier (PA) or a Buffer (BUF), an envelope detector (envelope detector, ED), and a coupling element (e.g., an antenna). Two-way communication between the two isolated ends can be realized, and the normal signal (shown by a purple dotted line in fig. 1) from the transmitting end TX to the receiving end RX and the abnormal signal (shown by an orange dotted line in fig. 1) from the receiving end RX to the transmitting end TX exist at the same time. In the digital isolator with the backhaul function, the matching network in the transmitting end TX/receiving end RX needs to have the capability of matching the normal signal and the abnormal signal at the same time. I.e. having the capability of matching both the envelope detector ED and the coupling and the signal amplifier (PA/BUF) to the coupling. Particularly, for the matching network of the receiving end RX, since the normal signal transmitted through the forward transmission channel (the purple transmission link in fig. 1) has a high speed, the requirement on the impedance matching capability of the receiving end RX is higher, which belongs to the technical difficulty in the field. By matching, it is meant impedance matching (matching) and it is meant that the electronic device is made to meet certain conditions by adjusting the input impedance and the output impedance, typically either to maximize the system transmission power or to minimize signal reflection. For example, in a wireless transmission system to which a digital isolator belongs, the impedance of a transmitting device and a receiving element can be matched to achieve the purpose of maximizing isolation transmission power, eliminating signal reflection, transmitting signal energy to the maximum extent, ensuring the performance optimization of the system and the like. Disclosure of Invention The invention aims to solve the technical problem of providing the optimized matching digital isolator and the application circuit thereof, which can pointedly optimize the impedance matching capacity of a matching network in a transmitting end/receiving end in the digital isolator with a return function so as to realize the maximization of the isolated bidirectional transmission power. In order to solve the technical problems, the invention adopts a technical scheme that: The digital isolator for optimizing matching comprises a first isolation circuit and a second isolation circuit which are respectively positioned at two sides of an isolation belt, wherein the first isolation circuit comprises a first coupling piece, a first matching network, a first envelope detector and a first signal amplifier, the second isolation circuit comprises a second coupling piece, a second matching network, a second envelope detector and a second signal amplifier, the first coupling piece, the first envelope detector and the first signal amplifier are respectively connected with the first matching network, and the second coupling piece, the second envelope detector and the second signal amplifier are respectively connected with the second matching network; the second signal amplifier is configured to modulate the received abnormal signal into a high-frequency signal and then send the high-frequency signal to the second matching network; the second matching network is configured to receive the normal signal sent by the second coupling element and send the high-frequency signal out through the second coupling element in a low-level neutral position of the normal signal; the first matching network is configured to receive the high-frequency signal sent by the first coupling element and then to couple and transmit the high-frequency signal to the first envelope detector; The first envelope detector is configured to send out prompt information if a high-frequency signal can be detected from a low-level neutral position of a coupling signal sent by the first matching network; the first matching network and/or the second matching network is an RF transformer, the RF transformer comprises a first winding, a second winding and a third winding, the first winding is connected with a corresponding signal amplifier, the second winding is connected with a corresponding antenna, and the third winding is connected with a corresponding envelope detector. Optionally, the second matching network is a second RF transformer, a first winding of the second RF transformer is connected to the second signal amplifier, a second winding of the second RF transformer is connected to the second coupling element, and a third winding of the second RF tran