Fast converter for crossing voltage domains

Abstract

A voltage domain crossing circuit and method are disclosed. In one embodiment, the voltage domain crossing circuit comprises an AC coupling component, a DC biasing component and a high voltage output amplifier. The AC coupling component receives an input low voltage signal and AC couples and splits the signal into two voltages. The two voltages are then DC biased to a predetermined bias voltage using the DC biasing component. The high voltage output amplifier then amplifies the biased voltages in the high voltage domain yielding a signal in the high voltage domain. Other embodiments of the voltage domain crossing circuit and method are also disclosed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.

FIG. 1 is a high level diagram illustrating the problem of crossing voltage domains.

FIG. 2 illustrates a prior art circuit for enabling boundary crossing from high to low voltage domains.

FIG. 3 illustrates a prior art circuit for enabling boundary crossing from low to high voltage domains.

FIG. 4 illustrates a high-level schematic of a voltage domain crossing circuit in accordance with one embodiment of the present invention.

FIG. 5 illustrates a voltage domain crossing circuit in accordance with one embodiment of the present invention.

FIG. 6 illustrates a voltage domain crossing circuit with an improved bias circuit in accordance with another embodiment of the present invention.

FIG. 7 illustrates a voltage domain crossing circuit in accordance with a preferred embodiment of the present invention.

FIG. 8 is a block diagram of the steps of a method for voltage domain crossing in accordance with one embodiment of the present invention.

Claims

1. A voltage domain crossing circuit comprising: an AC coupling component for receiving and splitting a low voltage signal into first and second voltages;a DC biasing component, coupled to the AC coupling component, for DC biasing the first and second voltages, anda high voltage output amplifier, coupled to the DC biasing component, for amplifying the DC biased first and second voltages in the high voltage domain and outputting a signal in the high voltage domain.

2. The circuit of claim 1, further comprising a low voltage input amplifier, coupled to the AC coupling component, for amplifying the input low voltage signal.

3. The circuit of claim 1, wherein the AC coupling component comprises a first capacitor and a second capacitor.

4. The circuit of claim 3, wherein the DC biasing component comprises a first resistor and a second resistor coupled to the first capacitor and the second capacitor, respectively, of the AC coupling component.

5. The circuit of claim 3, wherein the output amplifier further comprises an inverter having a first transistor and a second transistor coupled to the first and second capacitors respectively of the AC coupling component.

6. The circuit of claim 3, wherein the first and second capacitors are pre-charged to a predetermined voltage using high-ohmic resistors.

7. The circuit of claim 3, wherein the DC biasing component is an improved bias circuit comprising a first transistor and a second transistor coupled across the first and second bias resistors

8. The circuit of claim 1, further comprising a DC bias generation circuit.

9. A voltage domain crossing circuit comprising: an AC coupling component, having a first capacitor and a second capacitor, for receiving and splitting a low voltage signal into first and second voltages;a DC biasing component, having a first resistor and a second resistor coupled to the first capacitor and the second capacitor, respectively, of the AC coupling component, for DC biasing the first and second voltages received from the AC coupling component, anda high voltage output amplifier, coupled to the DC biasing component, for amplifying the DC biased first and second voltages in the high voltage domain and outputting a signal in the high voltage domain.

10. The circuit of claim 9, further comprising a low voltage input amplifier, coupled to the AC coupling component, for amplifying the input low voltage signal.

11. The circuit of claim 9, wherein the output amplifier further comprises an inverter having a first transistor and a second transistor coupled to the first and second capacitors respectively of the AC coupling component.

12. The circuit of claim 9, wherein the first and second capacitors are pre-charged to a predetermined voltage using high-ohmic resistors.

13. The circuit of claim 9, wherein the DC biasing component is an improved bias circuit further comprising a first transistor and a second transistor coupled across the first and second resistors

14. The circuit of claim 9, wherein the DC biasing component further comprises diode connected transistors.

15. A voltage domain crossing circuit comprising: an AC coupling component for receiving and splitting a low voltage signal into first and second voltages;a DC biasing component, coupled to the AC coupling component, for DC biasing the first and second voltages using a predetermined bias voltage,a DC bias generation component, coupled to the DC biasing component, for generating the predetermined bias voltage; anda high voltage output amplifier, coupled to the DC biasing component, for amplifying the DC biased first and second voltages in the high voltage domain and outputting a signal in the high voltage domain.

16. The circuit of claim 15, further comprising a low voltage input amplifier, coupled to the AC coupling component, for amplifying the input low voltage signal.

17. The circuit of claim 15, wherein the AC coupling component comprises a first capacitor and a second capacitor.

18. The circuit of claim 17, wherein the DC biasing component comprises a first resistor and a second resistor coupled to the first capacitor and the second capacitor, respectively, of the AC coupling component.

19. The circuit of claim 17, wherein the output amplifier further comprises an inverter having a first transistor and a second transistor coupled to the first and second capacitors respectively of the AC coupling component.

20. The circuit of claim 17, wherein the first and second capacitors are pre-charged to a predetermined voltage using high-ohmic resistors.

21. The circuit of claim 17, wherein the DC bias component is an improved bias circuit comprising a first transistor and a second transistor coupled across the first and second bias resistors.

22. The circuit of claim 17, wherein the DC bias generation component comprises diode connected transistors coupled to the DC bias component.

23. A method for transforming voltage domains signals comprising the steps of: AC coupling an input low voltage signal;splitting the low voltage signal into a first voltage and a second voltage;DC biasing the first and second voltages; andamplifying the first and second voltages in the high voltage domain.

24. The method of claim 15, further comprising the step of amplifying the input low voltage signal after it has been received.