SPREAD SPECTRUM ISOLATOR

• US 20080119142A1
• Filed: 11/27/2007
• Published: 05/22/2008
• Est. Priority Date: 06/03/2004
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Dupuis, Timothy
• Granted Patent: US 7,650,130 B2
• Time in Patent Office: Days
• US Class Current: 455/67.15
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48095 Kinked
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 23/49503 characterised by the die pad
• CPC Class Codes: H01L 23/4952 the additional leads being a bump or a wire
• CPC Class Codes: H01L 23/49575 Assemblies of semiconductor devices on lead frames
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 24/06 of a plurality of bonding areas
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• 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 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/1204 : Optical Diode
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/13055 : Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19042 : being an inductor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/30105 : Capacitance
• 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: H02M 3/33523 : with galvanic isolation between input and output of both the power stage and the feedback loop
• CPC Class Codes: H04L 25/0266 : Arrangements for providing Galvanic isolation, e.g. by means of magnetic or capacitive coupling

Abstract

An apparatus comprising a functional circuitry on a first die. Said function circuitry configured to drive an RF voltage isolation link with an RF signal responsive to receipt of a logic signal at a first logic state. Control circuitry modifies the frequency of the RF signal to spread harmonics to other than a fundamental frequency.

Claims

1. An apparatus, comprising:

functional circuitry on a first die, said function circuitry configured to drive an RF voltage isolation link with an RF signal responsive to receipt of a logic signal at a first logic state; and

control circuitry for modifying the frequency of the RF signal to spread harmonics to other than a fundamental frequency.

2. The apparatus of claim 1, wherein the functional circuitry does not drive the RF voltage isolation link with the RF signal responsive to receipt of the logic signal at other than the first logic state.

3. The apparatus of claim 1, wherein the control circuitry modifies the frequency of the RF signal to oscillate at a first level responsive to an input control signal at a first level and modifies the frequency of the RF signal to oscillate at a second level responsive to the input control signal at a second level.

4. The apparatus of claim 1, wherein the functional circuitry further comprises:

a transformer included within the RF voltage isolation link; and

a transmitter associated with the transformer for transmitting the RF signal onto the RF voltage isolation link.

5. The apparatus of claim 1, wherein the control circuitry further comprises:

a slow ring oscillator;

a divider circuit connected to the slow ring oscillator for generating a control code that represents the input control signal and at least the first or second generated values; and

an LC oscillator circuit responsive to the control code from the divider circuit for generating the RF carrier signal, wherein the control code causes the generation of one of a plurality of frequencies, at least two of which comprise the first and second frequencies.

6. The apparatus of claim 1, wherein the control circuitry further comprises:

an LC oscillator circuit for generating the RF carrier signal responsive to a control code that represents the input control signal and at least the first or second generated values, wherein the control code causes the generation of one of a plurality of frequencies, at least two of which comprise the first and second frequencies; and

a divider circuit connected in a feedback loop with the LC oscillator for generating the control code.

7. The system of claim 1, wherein the circuitry for generating the RF carrier signal further comprises:

a slow ring oscillator;

a circuit for randomly generating a control code responsive to an input from the slow ring oscillator that represents the input control signal and at least the first or second generated values; and

an LC oscillator circuit responsive to the randomly generated control code for generating the RF carrier signal, wherein the randomly generated control code causes the generation of one of a plurality of frequencies, at least two of which comprise the first and second frequencies.

8. The system of claim 7, wherein the circuit further comprises:

a divider circuit for providing a clock signal;

a shift register for providing a plurality of output bits responsive to the clock signal and a data signal;

logic circuitry for generating the data signal responsive to a first portion of the plurality of output bits; and

wherein the randomly generated control code comprises a second portion of the plurality of output bits.

9. The system of claim 8, wherein the shift register further comprises a de Bruijn counter.

10. A method for providing on RF voltage isolation link, comprising the steps of:

driving the RF voltage isolation link with an RF signal responsive to the receipt of a logic signal to a first logic state; and

modifying the frequency of the RF signal to spread harmonics to other than a fundamental frequency.

11. The method of claim 10 further including the step of not driving the RF voltage isolation link with the RF signal responsive to receipt of the logic signal at other than the first logic state.

12. The method of claim 10, wherein the step of modifying further comprises the step of modifying the frequency of the RF signal to oscillate at a first level responsive to an input at a first level and modifying the frequency of the RF signal to oscillate at a second level responsive to an input at a second level.

13. The method of claim 10 further including the step of receiving the RF signal over the RF voltage isolation link.

14. The method of claim 13 further including the steps of:

detecting whether the RF signal is present on the RF isolation link;

determining receipt of the logic signal at the first logic state if the RF signal is present on the RF voltage isolation link; and

determining receipt of the logic signal at a second logic state if the RF signal is not present on the RF voltage isolation link.

15. The method of claim 10, wherein the step of modifying further comprises the step of:

generating a control code representing a control input;

generating the RF carrier signal responsive to the control code, wherein the control code causes the generation of one of a plurality of frequencies, at least two of which comprise the first and second frequencies.

16. The method of claim 15, wherein the step of generating the control code further comprises the step of randomly generating the control code representing the control input.