Transmitting and receiving digital and analog signals across an isolator

• US 9,000,675 B2
• Filed: 07/16/2014
• Issued: 04/07/2015
• Est. Priority Date: 09/21/2010
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Chang, Kwee Chong, Peng, Jia, Ng, Gek Yong, Lum, Kok Keong Richard
• Primary Examiner(s): Hammond, Crystal L
• Application Number:
  US14/333,411
• Publication Number:
  US 20140328427A1
• Time in Patent Office: 265 Days
• Field of Search: None
• US Class Current: 315/201
• CPC Class Codes: H04B 10/802 for isolation, e.g. using optocouplers
• CPC Class Codes: H04L 27/10 Frequency-modulated carrier systems, i.e. using frequency-shift keying H04L27/32 takes precedence
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: H05B 45/50 responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
• CPC Class Codes: H05B 47/24 Circuit arrangements for protecting against overvoltage
• CPC Class Codes: H05B 47/25 Circuit arrangements for protecting against overcurrent

Abstract

Various embodiments of systems for transmitting and receiving digital and/or analog signals across a single isolator, solid state lighting systems, or DC/DC converter feedback regulation control systems are disclosed. In one embodiment, a first signal may be modulated into a first modulated signal. The first modulated signal is then modulated into a second modulated signal in accordance to a second signal. The second modulated signal is in turn, modulated into a third modulated signal in accordance to a third signal. At least some of the apparatuses, circuits, systems and methods disclosed herein may be implemented using conventional CMOS design and manufacturing techniques and processes to provide, for example, at least one or more integrated circuits.

Claims

1. An isolator system, comprising:

a first circuit, the first circuit having an analog signal and a digital signal;

a second circuit being proximate to but distanced away from the first circuit;

an isolation material configured to electrically isolate the first circuit from the second circuit;

a first modulator of the first circuit, the first modulator configured to modulate one of the analog signal and the digital signal to form a first modulated signal as output of the first modulator;

a second modulator of the first circuit, the second modulator configured to modulate the other one of the analog signal and the digital signal with the first modulated signal to form a second modulated signal as output of the second modulator;

a transmitting circuit of the first circuit configured to generate a transmission signal that correspond to the analog signal and the digital signal, and configured to transmit the transmission signal across the isolation material from the first circuit to the second circuit;

a receiver of the second circuit configured to detect the transmission signal and generate a reproduced transmission signal as its output; and

a retrieval circuit of the second circuit configured to reconstruct the digital signal and the analog signal from the reproduced transmission signal.

2. The isolator system of claim 1, wherein the first circuit further comprises a third modulator, the third modulator configured to modulate an additional signal with the second modulated signal, to produce a third modulated signal as output of the third modulator.

3. The isolator system of claim 2 wherein the third modulator comprises an amplitude modulation circuit configured to modulate the second modulated signal in accordance with the additional signal.

4. The isolator system of claim 2 wherein the third modulator comprises a sigma delta modulation circuit configured to modulate the second modulated signal in accordance with the additional signal.

5. The isolator system of claim 2, wherein the second modulator has a higher precision in modulating analog signals as compared to the third modulator.

6. The isolator system of claim 2, wherein the third modulator is configured to modulate analog signals with precision of at least three-bit accuracy.

7. The isolator system of claim 2, wherein the second modulator is configured to modulate analog signals with precision of at least eight-bit accuracy.

8. The isolator system of claim 2, wherein the first circuit comprises a temperature sensor configured to generate a temperature signal.

9. The isolator system of claim 8 wherein the temperature sensor is a low precision sensor configured to produce the temperature signal having less than three-bit precision.

10. The isolator system of claim 8, wherein the temperature signal of the temperature sensor is coupled to the third modulator as an input to the third modulator either directly or indirectly.

11. The isolator system of claim 2 wherein the first circuit further comprises an encoder circuit coupled to the third modulator, and wherein the encoder circuit is configured to convert a pulse signal into a major pulse and a minor pulse.

12. The isolator system of claim 1, wherein the isolator system forms a portion of a direct current to direct current converter feedback regulation control system.

13. The isolator system of claim 1, wherein the first modulator comprises a wave generator circuit configured to generate a wave signal.

14. The isolator system of claim 13, wherein the wave generator circuit is configured to generate the wave signal in a first frequency when the one of the analog signal and the digital signal is in a first state and is configured to generate the wave signal in a second frequency when the one of the analog signal and the digital signal is in a second state, wherein the first frequency is different from the second frequency.

15. The isolator system of claim 1, wherein the first modulator comprises a frequency modulation circuit configured to perform frequency modulation.

16. The isolator system of claim 1, wherein the second modulator comprises a comparator electrically coupled to the first modulated signal, and the other one of the analog signal and the digital signal, and wherein the comparator is configured to generate the second modulated signal as output.

17. The isolator system of claim 1, wherein the second modulator comprises a pulse width modulation circuit configured to perform pulse width modulation in accordance to the other one of the analog signal and the digital signal.

18. The isolator system of claim 1, wherein the first modulator comprises a code division modulation circuit configured to perform code division modulation in accordance with the one of the analog signal and the digital signal.

19. The isolator system of claim 1, wherein the second modulator comprises a sigma delta modulation circuit configured to perform sigma delta modulation in accordance with the other one of the analog signal and the digital signal.

20. The isolator system of claim 1, wherein:

the second modulated signal comprises a plurality of pulses; and

the first circuit comprises an encoder configured to encode each pulse of the second modulated signal into an encoded signal having a major pulse and a minor pulse respectively.

21. The isolator system of claim 20, wherein the transmitting circuit is coupled to the encoder, and the transmitting circuit is configured to transmit the encoded signal across the isolation material to the second circuit.

22. The isolator system of claim 21, wherein the second circuit comprises a decoder configured to reproduce the second modulated signal from the major pulse and the minor pulse of the encoded signal.

23. An isolator adapted to convey a first signal and a second signal from a first circuit to a second circuit isolated from the first circuit, the isolator comprising:

a transmitter die having input terminals configured to receive the first signal and the second signal;

a receiver die having output terminals configured to output a reproduced first signal and a reproduced second signal;

an isolation material surrounding the transmitter die so as to electrically isolate the transmitter die from the receiver die;

a first modulator circuit formed within the transmitter die, the first modulator circuit being configured to receive the first signal and generate a first modulated signal that is modulated in accordance with the first signal as output of the first modulator circuit;

a second modulator circuit formed within the transmitter die, the second modulator circuit being configured to modulate the second signal with the first modulated signal to form a second modulated signal as output of the second modulator circuit;

an emitter configured to generate a transmission signal that correspond to the first signal and the second signal, and configured to transmit the transmission signal across the isolation material from the transmitter die to the receiver die; and

a receiver of the receiver die configured to detect the transmission signal and reproduce as output to the receiver, the reproduced first signal and the reproduced second signal.

24. The isolator of claim 23 further comprising a third modulator circuit formed within the transmitter die, wherein the third modulator circuit is configured to modulate the second modulated signal in accordance with a third signal to produce a third modulated signal.

25. The isolator of claim 24 further comprising an encoder circuit formed within the transmitter die, wherein the encoder circuit is configured to convert a pulse of the third modulated signal into a major pulse and a minor pulse.

26. The isolator of claim 25 further comprising a decoder circuit formed within the receiver die, wherein the decoder circuit is configured to convert the major pulse and the minor pulse generated by the encoder circuit into a reproduced pulse signal.

27. The isolator of claim 24, wherein the transmitter die further comprises a third input terminal configured to be coupled to a low resolution temperature sensor, wherein the low resolution temperature sensor is configured to generate the third signal.

28. The isolator of claim 24, wherein the third modulator circuit has a substantially lower resolution compared to the second modulator circuit.

29. The isolator of claim 23, further comprising an encoder circuit formed within the transmitter die, wherein the encoder circuit is configured to convert a pulse of the second modulated signal into a major pulse and a minor pulse.

30. The isolator of claim 29 further comprising a third modulator circuit coupled to the encoder circuit, wherein the third modulator circuit is configured to modulate the major pulse and the minor pulse in accordance with a third signal.

31. A method for conveying a first signal and a second signal across an isolation material from a first system to a second system, the method comprising:

modulating a first signal into a first modulated signal;

modulating the first modulated signal in accordance with a second signal to produce a second modulated signal;

transmitting the first signal and the second signal across the isolation material as a radiation signal;

receiving the radiation;

reconstructing the first signal from the radiation signal into a reconstructed first signal; and

reconstructing the second signal from the radiation signal into a reconstructed second signal.

32. The method of claim 31 further comprising modulating the second modulated signal in accordance with a third signal.

33. The method of claim 31, further comprising encoding one of the first modulated signal and the second modulated signal by encoding a pulse signal into a major pulse and a minor pulse.

34. The method of claim 31 further comprising generating a temperature signal indicative of a temperature reading of the first system, and modulating the second modulated signal in accordance with the temperature signal.

35. A transmitting device adapted to transmit a first signal and a second signal across an isolation material, the transmitting device comprising:

a first modulator configured to modulate the first signal into a first modulated signal;

a second modulator configured to modulate the second signal with the first modulated signal so as to generate a second modulated signal; and

a transmitter circuit coupled to the second modulator configured to generate a drive signal corresponding to the second modulated signal so as to drive an external emitter.