Oscillating circuit with reduced decay and transient times

• US 6,822,521 B2
• Filed: 06/02/2003
• Issued: 11/23/2004
• Est. Priority Date: 06/24/2000
• Status: Expired due to Term

• Current Assignee: Atmel Germany GmbH (Microchip Technology Incorporated)
• Original Assignee: Atmel Germany GmbH (Microchip Technology Incorporated)
• Inventors: Hanselmann, Dieter
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Chang, Joseph
• Application Number:
  US10/453,233
• Publication Number:
  US 20030206069A1
• Time in Patent Office: 540 Days
• Field of Search: 331/117.R, 331/74, 331/14, 331/55, 331/167
• US Class Current: 331/117.00R
• CPC Class Codes: H03B 11/10 interrupter being semiconductor device
• CPC Class Codes: H03L 3/00 Starting of generators

Abstract

A circuit arrangement for reducing the decay and build-up transient times of an intermittently operating oscillating circuit increases the data transmission rate of a transmission unit using such an oscillating circuit. A control unit is connected to the oscillating circuit including a capacitor, a coil, and a resistor. A switch element controlled by the control unit selectively connects a voltage source to the capacitor, or selectively connects a current source to the coil. In the former case, another switch element selectively disconnects the capacitor from the coil and the resistor. In this circuit arrangement the current and/or the voltage are maintained when the excitation voltage for the oscillating circuit is interrupted. This eliminates the decay of the oscillating circuit amplitudes. When the excitation voltage is switched on again, the oscillating circuit continues oscillating without delay.

Claims

1. A circuit arrangement comprising:

an oscillating circuit including a capacitor and a coil;

a control unit connected by first and second energizing leads to said oscillating circuit and adapted to selectively energize an oscillation of said oscillating circuit through said energizing leads;

an electrical source having a source output terminal, and having a source control terminal connected to said control unit; and

a first switching element that is interposed and connected between said source output terminal of said source and said oscillating circuit, and that has a first switch control terminal connected to said control unit;

wherein said oscillating circuit is a parallel circuit having said capacitor and said coil connected in parallel with each other, said first energizing lead and said second energizing lead are respectively connected to opposite first and second sides of said capacitor and of said coil, said first switching element is interposed and connected between said source output terminal and said second side of said capacitor and of said coil, and said oscillating circuit further comprises a resistor connected in parallel between said first side and said second side.

4. The circuit arrangement according to claim 1, wherein said electrical source is a current source.

5. The circuit arrangement according to claim 4, wherein said second side of said capacitor and said second side of said coil are permanently and constantly connected to each other.

6. The circuit arrangement according to claim 4, wherein said current source is a fixed constant current source.

2. A circuit arrangement comprising:

an oscillating circuit including a capacitor and a coil;

a control unit connected by first and second energizing leads to said oscillating circuit and adapted to selectively energize an oscillation of said oscillating circuit through said energizing leads;

a controllable variable current source having a source output terminal, and having a source control terminal connected to said control unit; and

a first switching element that is interposed and connected between said source output terminal of said source and said oscillating circuit, and that has a first switch control terminal connected to said control unit;

wherein said oscillating circuit is a parallel circuit having said capacitor and said coil connected in parallel with each other, said first energizing lead and said second energizing lead are respectively connected to opposite first and second sides of said capacitor and of said coil, and said first switching element is interposed and connected between said source output terminal and said second side of said capacitor and of said coil.

3. A circuit arrangement comprising:

an oscillating circuit including a capacitor and a coil;

a control unit connected by first and second energizing leads to said oscillating circuit and adapted to selectively energize an oscillation of said oscillating circuit through said energizing leads;

a current source having a source output terminal, and having a source control terminal connected to said control unit; and

a first switching element that is interposed and connected between said source output terminal of said source and said oscillating circuit, and that has a first switch control terminal connected to said control units;

wherein said oscillating circuit is a parallel circuit having said capacitor and said coil connected in parallel with each other, said first energizing lead and said second energizing lead are respectively connected to opposite first and second sides of said capacitor and of said coil, and said first switching element is interposed and connected between said source output terminal and said second side of said capacitor and of said coil; and

wherein said control unit is adapted to control said first switching element via said first switch control terminal so as to connect said source output terminal of said current source to said second side of said coil and of said capacitor when said control unit is not energizing said oscillation through said energizing leads, and so as to disconnect said source output terminal of said current source from said second side of said coil and said capacitor when said control unit is energizing said oscillation through said energizing leads.

7. A circuit arrangement comprising:

an oscillating circuit including a capacitor and a coil;

a control unit connected by first and second energizing leads to said oscillating circuit and adapted to selectively energize an oscillation of said oscillating circuit through said energizing lead;

a voltage source having a source output terminal, and having a source control terminal connected to said control unit; and

a first switching element that is interposed and connected between said source output terminal of said source and said oscillating circuit, and that has a first switch control terminal connected to said control unit;

wherein said oscillating circuit is a parallel circuit having said capacitor and said coil connected in parallel with each other, said first energizing lead and said second energizing lead are respectively connected to opposite first and second sides of said capacitor and of said coil, and said first switching element is interposed and connected between said source output terminal and said second side of said capacitor and of said coil.

8. The circuit arrangement according to claim 7, wherein said voltage source is a controllable variable voltage source.

9. The circuit arrangement according to claim 7, wherein said voltage source is a fixed constant voltage source.

10. The circuit arrangement according to claim 7, further comprising a second switching element, that is arranged in said oscillating circuit, and that is interposed and connected between said capacitor and said coil on said first side or on said second side, and that has a second switch control terminal connected to said control unit.

11. The circuit arrangement according to claim 10, wherein said first switching element is connected and interposed directly between said capacitor and said source output terminal of said voltage source, and wherein said first switching element and said second switching element are connected in series with each other between said coil and said source output terminal of said voltage source.

12. The circuit arrangement according to claim 10, wherein said control unit is adapted to control said first switching element via said first switch control terminal and to control said second switching element via said second switch control terminal so as to connect said source output terminal of said voltage source to said second side of said capacitor and to disconnect said coil from said capacitor and from said source output terminal of said voltage source when said control unit is not energizing said oscillation through said energizing leads, and so as to disconnect said source output terminal of said voltage source from said second side of said coil and said capacitor and to connect said coil to said capacitor when said control unit is energizing said oscillation through said energizing leads.

13. A circuit arrangement comprising:

an oscillating circuit including a capacitor and a coil;

a control unit connected by first and second energizing leads to said oscillating circuit and adapted to selectively energize an oscillation of said oscillating circuit through said energizing leads;

an electrical source having a source output terminal, and having a source control terminal connected to said control unit; and

a first switching element that is interposed and connected between said source output terminal of said source and said oscillating circuit, and that has a first switch control terminal connected to said control unit;

wherein said oscillating circuit is a series circuit having said capacitor and said coil connected in series with each other, whereby an intermediate node is provided therebetween, said first energizing lead is connected to a first side of said coil opposite said intermediate node, said second energizing lead is connected to a second side of said capacitor opposite said intermediate node, and said first switching element is interposed and connected between said source output terminal and said intermediate node.

14. The circuit arrangement according to claim 13, wherein said oscillating circuit further comprises a resistor connected in series with said coil between said intermediate node and said first energizing lead.

15. The circuit arrangement according to claim 13, wherein said electrical source is a current source.

16. The circuit arrangement according to claim 15, wherein said capacitor and said coil are permanently and constantly connected to each other through said intermediate node.

17. The circuit arrangement according to claim 15, wherein said current source is a controllable variable current source.

18. The circuit arrangement according to claim 15, wherein said current source is a fixed constant current source.

19. The circuit arrangement according to claim 15, wherein said control unit is adapted to control said first switching element via said first switch control terminal so as to connect said source output terminal of said current source to said intermediate node when said control unit is not energizing said oscillation through said energizing leads, and so as to disconnect said source output terminal of said current source from said intermediate node when said control unit is energizing maid oscillation through said energizing leads.

20. The circuit arrangement according to claim 13, wherein said electrical source is a voltage source.

21. The circuit arrangement according to claim 20, wherein said voltage source is a controllable variable voltage source.

22. The circuit arrangement according to claim 20, wherein said voltage source is a fixed constant voltage source.

23. The circuit arrangement according to claim 20, further comprising a second switching element, that is arranged in said oscillating circuit, and that is interposed and connected between said intermediate node and said coil, and that has a second switch control terminal connected to said control unit.

24. The circuit arrangement according to claim 23, wherein said first switching element is connected via said intermediate node and interposed directly between said capacitor and said source output terminal of said voltage source, and wherein said first switching element and said second switching element are connected in series with each other via said intermediate node between said coil and said source output terminal of said voltage source.

25. The circuit arrangement according to claim 23, wherein said control unit is adapted to control said first switching element via said first switch control terminal and to control said second switching element via said second switch control terminal so as to connect said source output terminal of said voltage source via said intermediate node to said capacitor and to disconnect said coil from said intermediate node, said capacitor and said source output terminal of said voltage source when said control unit is not energizing said oscillation through said energizing leads, and so as to disconnect said source output terminal of said voltage source from said intermediate node and to connect said coil to said capacitor via said intermediate node when said control unit is energizing said oscillation through said energizing leads.

26. A method of operating a circuit arrangement including:

an oscillating circuit including a capacitor and a coil;

a control unit connected by first and second energizing leads to said oscillating circuit and adapted to selectively energize an oscillation of said oscillating circuit through said energizing leads;

a current source having a source output terminal, and having a source control terminal connected to said control unit; and

a first switching element that is interposed and connected between said source output terminal of said source and said oscillating circuit, and that has a first switch control terminal connected to said control unit;

for reducing at least a start-up transient time of said oscillation, wherein said method comprises the steps;

a) operating said control unit to energize said oscillation of said oscillating circuit through said energizing leads, and to open said first switching element so as to disconnect said source output terminal of said current source from said oscillating circuit;

b) operating said control unit to cease said energizing of said oscillation of said oscillating circuit through said energizing leads, to close said first switching element so as to connect said source output terminal of said current source to said oscillating circuit and thereby to drive a current from said current source through said coil; and

c) repeating said step a) and b).

27. The method according to claim 26, wherein said current source is operated to provide said current as a constant current during said step b) with a current magnitude matching an instantaneous magnitude of a current flowing an said coil upon ending said step a) and beginning said step b).

28. The method according to claim 27, wherein said instantaneous magnitude is a maximum magnitude of said current flowing in said coil during said oscillation.

29. A method of operating a circuit arrangement including:

an oscillating circuit including a capacitor and a coil;

a control unit connected by first and second energizing leads to said oscillating circuit and adapted to selectively energize an oscillation of said oscillating circuit through said energizing leads;

a voltage source having a source output terminal, and having a source control terminal connected to said control unit;

a first switching element that is interposed and connected between said source output terminal of said source and said oscillating circuit, and that has a first switch control terminal connected to said control unit; and

a second switching element that is arranged and connected between said coil and said capacitor so as to selectively connect and disconnect said coil and said capacitor relative to each other and that has a second switch control terminal connected to said control unit;

for reducing at least a start-up transient time of said oscillation, wherein said method comprises the steps;

a) operating said control unit to energize said oscillation of said oscillating circuit through said energizing leads, to open said first switching element so as to disconnect said source output terminal of said voltage source from said oscillating circuit, and to close said second switching element so as to connect said coil and said capacitor relative to each other;

b) operating said control unit to cease said energizing of said oscillation of said oscillating circuit through said energizing leads, to close said first switching element so as to connect said source output terminal of said voltage source to said oscillating circuit and thereby to apply a voltage from said voltage source to said capacitor, and to open said second switching element so as to disconnect said coil from said capacitor; and

c) repeating said steps a) and b).

30. The method according to claim 29, wherein said voltage source is operated to provide said voltage as a constant voltage during said step b) with a voltage magnitude matching an instantaneous magnitude of a voltage on said capacitor upon ending said step a) and beginning said step b).

31. The method according to claim 30, wherein said instantaneous magnitude is a maximum magnitude of said voltage on said capacitor during said oscillation.