Non-optical signal isolator

• US 6,873,065 B2
• Filed: 04/19/2001
• Issued: 03/29/2005
• Est. Priority Date: 10/23/1997
• Status: Expired due to Term

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Chen, Baoxing, Haigh, Geoffrey T.
• Primary Examiner(s): DeBeradinis, Robert L.
• Application Number:
  US09/838,520
• Publication Number:
  US 20020135236A1
• Time in Patent Office: 1,440 Days
• Field of Search: 307/91, 307/412, 307/89, 257/531
• US Class Current: 307/412
• CPC Class Codes: H01L 2224/05553 being rectangular
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 23/5222 Capacitive arrangements or effects of, or between wiring layers other capacitive arrangements H01L23/642
• CPC Class Codes: H01L 23/5223 Capacitor integral with wiring layers
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 23/60 Protection against electrostatic charges or discharges, e.g. Faraday shields
• CPC Class Codes: H01L 23/642 Capacitive arrangements H01L23/49589, H01L23/645, H01L23/647, H01L23/66 take precedence; capacitive effects between wiring layers on the semiconductor body H01L23/5222
• CPC Class Codes: H01L 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• CPC Class Codes: H01L 25/16 the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/10253 Silicon [Si]
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/22 : Capacitive coupling
• CPC Class Codes: H04B 5/266 : One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/73 : for taking measurements, e.g. using sensing coils
• CPC Class Codes: H04B 5/75 : for isolation purposes
• CPC Class Codes: H04L 25/0266 : Arrangements for providing Galvanic isolation, e.g. by means of magnetic or capacitive coupling
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

A non-optical isolator having a driver circuit for providing an input signal to one or more first passive components which are coupled across a galvanic isolation barrier to one or more corresponding second passive components, and an output circuit that converts the signal from the second passive components to an output signal corresponding to the input signal. The entire structure may be formed monolithically as an integrated circuit on one or two die substrates, for low cost, small size, and low power consumption. The passive components may be coils or capacitor plates, for example. When the first and second passive components are capacitor plates, a Faraday shield may be provided between them, with the first and second passive components being referenced to separate grounds and the Faraday shield referenced to the same ground as the second passive components.

Claims

1. An information signal isolator comprising:

a first substrate;

a first passive component formed on the first substrate;

an isolation layer formed over the first passive component;

a second passive component formed over the isolation layer

the first and second passive components being coils;

an input for receiving an input signal; and

a driver circuit coupled between the input and one of said passive components.

3. The isolator of claim 1 or claim 2 wherein the first substrate is a semiconductor substrate.

4. The isolator of claim 3, wherein the driver circuit also is formed on the first semiconductor substrate.

5. The isolator of claim 3, further comprising a second substrate, wherein the driver circuit is formed on the second substrate.

6. The isolator of claim 1 or claim 2 wherein the first passive component is formed on top of the first substrate.

7. The isolator of claim 1 or claim 2 wherein the first passive component is formed into the first substrate.

8. The isolator of claim 1 or claim 2 further comprising a third passive component on the substrate, a second isolation layer over the third passive component, and a fourth passive component formed over the second isolation layer, wherein the driver circuit provides signals to the first and third passive components.

9. The isolator of claim 8, wherein the third and fourth passive components are capacitor plates.

10. The isolator of claim 8, wherein the first, second, third, and fourth passive components are coils.

11. The isolator of claim 10 wherein the first and second passive components are referenced to separate, galvanically isolated grounds, and further including a Faraday shield between the first and second passive components, with the Faraday shield referenced to the same ground as the second passive components.

12. The isolator of claim 1 or claim 2, further comprising a third passive component on the substrate, a second isolation layer over the third passive component, and a fourth passive component formed over the second isolation layer, wherein the driver circuit provides signals to the second and fourth passive components.

13. The isolator of claim 12 wherein the first and second isolation layers are a single layer.

14. The isolator of claim 1 wherein the first and second passive components are referenced to separate, galvanically isolated grounds, and further including a Faraday shield between the first and second passive components, with the Faraday shield referenced to the same ground as the second passive components.

2. An information isolator comprising:

a first substrate;

a first passive component formed on the first substrate;

an isolation layer formed over the first passive component;

a second passive component formed over the isolation layer;

the first and second passive components being capacitor plates;

an input for receiving an input signal; and

a driver circuit coupled between the input and one of said passive components.