Circuit arrangement and method for bidirectional data transmission

• US 9,197,291 B2
• Filed: 06/16/2014
• Issued: 11/24/2015
• Est. Priority Date: 06/17/2013
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Feldtkeller, Martin
• Primary Examiner(s): Flores, Leon
• Application Number:
  US14/305,008
• Publication Number:
  US 20140369433A1
• Time in Patent Office: 526 Days
• Field of Search: 375/258
• US Class Current: 1/1
• CPC Class Codes: H03K 2005/00143 Avoiding variations of delay due to temperature
• CPC Class Codes: H03K 5/06 by the use of delay lines or other analogue delay elements
• CPC Class Codes: H03K 5/065 using dispersive delay lines
• CPC Class Codes: H03K 5/1534 Transition or edge detectors
• CPC Class Codes: H03K 5/26 the characteristic being duration, interval, position, frequency, or sequence
• CPC Class Codes: H04B 2203/5483 using coupling circuits
• CPC Class Codes: H04B 3/56 Circuits for coupling, blocking, or by-passing of signals

Abstract

A transformer arrangement for signal transmission is provided, the transformer arrangement having at least one transformer with a primary coil and a secondary coil and a controller. The controller is configured in a magnetization phase to control a first current to flow through the primary coil to increase until a predefined criterion is fulfilled, wherein the magnetization phase is longer than a time constant of the primary coil of the at least one transformer. The controller is configured in a voltage application phase to apply a voltage to the at least one transformer so that a second current flows through the primary coil, wherein the second current has a polarity which changes during the voltage application phase compared with the first current, wherein the voltage application phase is shorter than two times the time constant of the primary coil of the at least one transformer.

Claims

1. A transformer arrangement for signal transmission, the transformer arrangement comprising:

at least one transformer comprising a primary coil and a secondary coil; and

a controller configured to

in a magnetization phase, control a first current to flow through the primary coil to increase until a predefined criterion is fulfilled, wherein the magnetization phase is longer than one of;

a time constant of the primary coil of the at least one transformer; and

two times the time constant of the primary coil of the at least one transformer;

in a voltage application phase, apply a voltage to the at least one transformer so that a second current flows through the primary coil, wherein the second current has a polarity which changes during the voltage application phase compared with the first current, wherein the voltage application phase is shorter than one of;

two times the time constant of the primary coil of the at least one transformer; and

the time constant of the primary coil of the at least one transformer.

2. The transformer arrangement of claim 1,

wherein the controller is further configured to, in a demagnetization phase, control a third current to flow through the primary coil to decrease, wherein the demagnetization phase is longer than one of:

the time constant of the primary coil of the at least one transformer; and

two times the time constant of the primary coil of the at least one transformer.

3. The transformer arrangement of claim 2, wherein the controller is further configured such that the demagnetization phase is one of:

in the range from 5 ns to 30 ns;

in the range from 7 ns to 20 ns;

in the range from 9 ns to 15 ns; and

10 ns.

4. The transformer arrangement of claim 1,

wherein the controller is configured to step-wise increase the first current to flow through the primary coil of the at least one transformer.

5. The transformer arrangement of claim 1,

wherein the at least one transformer is a coreless transformer.

6. The transformer arrangement of claim 1, further comprising:

a circuit coupled to the controller, the circuit comprising a plurality of subcircuits connected in parallel;

wherein each subcircuit comprises a series connection of a switch and a resistor;

wherein a first terminal of each subcircuit is coupled to a reference potential and a second terminal of each subcircuit is coupled to the at least one transformer.

7. The transformer arrangement of claim 6,

wherein the controller is configured to open all switches before the magnetization phase starts.

8. The transformer arrangement of claim 5,

wherein the controller is configured to close a first group of switches one after another to stepwise increase the current in the magnetization phase.

9. The transformer arrangement of claim 8,

wherein the controller is configured to open the first group of switches and to close a second group of switches during the voltage application phase.

10. The transformer arrangement of claim 9,

wherein the controller is configured to open the second group of switches one after another to stepwise decrease the current in the demagnetization phase.

11. The transformer arrangement of claim 6,

wherein the controller is configured to open all switches after the demagnetization phase has been terminated.

12. The transformer arrangement of claim 6,

wherein a resistance of at least some of the resistors is greater than the resistance of the primary coil.

13. The transformer arrangement of claim 12, wherein the resistance of at least some of the resistors is in the range from 10 Ohm to 1000 Ohm.

14. The transformer arrangement of claim 12, wherein the resistance of the primary coil is in the range from 1 Ohm to 50 Ohm.

15. The transformer arrangement of claim 6, further comprising:

another circuit coupled to the controller, the circuit comprising a plurality of subcircuits connected in parallel;

wherein each subcircuit comprises a series connection of a switch and a resistor;

wherein a first terminal of each subcircuit is coupled to a reference potential and a second terminal of each subcircuit is coupled to the at least one transformer, wherein the another circuit is connected with an opposite polarity to the transformer than the circuit.

16. The transformer arrangement of claim 15,

wherein the subcircuits of the circuit and of the another circuit share their respective resistors.

17. The transformer arrangement of claim 16,

wherein the resistance of all resistors are equal.

18. The transformer arrangement of claim 15,

wherein the switches of the subcircuits of the circuit and the another circuit are arranged symmetrically to each other.

19. The transformer arrangement of claim 15,

wherein the switches of the subcircuits of the circuit and the another circuit are controlled by the same control signal.

20. The transformer arrangement of claim 1,

wherein the at least one transformer comprises a plurality of transformers, each transformer of the plurality of transformers comprising a primary coil and a secondary coil;

wherein the primary coils of the plurality of transformers are connected in series; and

wherein a node between the primary coils is connected to a reference voltage.

21. The transformer arrangement of claim 20,

wherein the reference voltage is about half of a supply voltage.

22. The transformer arrangement of claim 1, wherein the controller is further configured such that the magnetization phase is one of:

in the range from 5 ns to 30 ns;

in the range from 7 ns to 20 ns;

in the range from 9 ns to 15 ns; and

10 ns.

23. The transformer arrangement of claim 1, wherein the controller is further configured such that the voltage application phase is one of:

in the range from 0.5 ns to 6 ns;

in the range from 1 ns to 4 ns; and

in the range from 2 ns to 3 ns.

24. The transformer arrangement of claim 1, wherein the time constant of the primary coil of the at least one transformer is one of:

in the range from 1 ns to 10 ns;

in the range from 2 ns to 6 ns; and

in the range from 3 ns to 4 ns.

25. A circuit arrangement comprising:

a first comparator circuit having a first comparator threshold;

a second comparator circuit having a second comparator threshold;

a third comparator circuit having a third comparator threshold;

a control circuit configured to

adapt the first comparator threshold such that the first comparator circuit is in a first comparator output state for a first time portion of a predefined time interval,

adapt the second comparator threshold such that the second comparator circuit is in a first comparator output state for a second time portion of the predefined time interval, wherein the second time portion is longer than the first time portion, and

set the third comparator threshold to be between the first comparator threshold and the second comparator threshold,

wherein the control circuit is configured to at least one of

adapt the first threshold based on the output signal provided by the first comparator circuit; and

adapt the second threshold based on the output signal provided by the second comparator circuit.

26. The circuit arrangement of claim 25,

wherein at least one of the first time portion and the second time portion are the sum of a plurality of time sub-portions.

27. The circuit arrangement of claim 25, further comprising:

at least one transformer comprising a primary coil and a secondary coil;

wherein the first comparator circuit, the second comparator circuit, and the third comparator circuit are coupled with the secondary coil.

28. The circuit arrangement of claim 25,

wherein the first comparator circuit, the second comparator circuit, and the third comparator circuit are all configured to receive the same signal.

29. The circuit arrangement of claim 25,

wherein at least one of the first comparator circuit and the second comparator circuit are configured as window comparator circuits.

30. The circuit arrangement of claim 25,

wherein the third comparator circuit is configured to provide an evaluation output signal.

31. The circuit arrangement of claim 30, further comprising:

a storage element coupled to the output of the third comparator circuit to store the evaluation output signal.

32. The circuit arrangement of claim 25,

wherein the control circuit is configured to at least one of

adapt the first threshold based on a time-based evaluation of the output signal provided by the first comparator circuit;

and

adapt the second threshold based on a time-based evaluation of the output signal provided by the second comparator circuit.

33. The circuit arrangement of claim 32,

wherein the control circuit is configured to at least one of

adapt the first threshold based on an averaging of the output signal provided by the first comparator circuit;

and

adapt the second threshold based on an averaging of the output signal provided by the second comparator circuit.

34. The circuit arrangement of claim 25,

wherein the control circuit is configured to at least one of

adapt the first threshold based on the output signal provided by the first comparator circuit, wherein a first signal state of the output signal and a second signal state of the output signal are weighted in a different manner;

and

adapt the second threshold based on the output signal provided by the second comparator circuit, wherein a first signal state of the output signal and a second signal state of the output signal are weighted in a different manner.

35. A transformer arrangement for signal transmission, the transformer arrangement comprising:

at least one transformer comprising a primary coil and a secondary coil;

the transformer arrangement having a resonance frequency;

a controller configured to terminate driving the primary coil so that the transformer arrangement is oscillating in the resonance frequency;

a switching circuit coupled to the secondary coil and configured to, in a first switching state, let the transformer arrangement oscillate, and, in a second switching state, to decrease the oscillation of the transformer arrangement,

further comprising;

driving the primary coil after a certain time period has passed after terminating driving the primary coil,

during the certain time before starting to drive the coil a bit is transmitted by detecting if the oscillation has decreased or not.

36. The transformer arrangement of claim 35,

wherein driving the primary coil comprises at least one of

a magnetization phase;

a demagnetization phase; and

a voltage application phase.

37. The transformer arrangement of claim 35,

wherein the certain time period is chosen to be long enough to decrease the oscillation if the switching circuit is in a second switching state and long enough that the decrease in oscillation can be detected in the amplitude detection circuit.

38. The transformer arrangement of claim 35, wherein

the time period during which the switching circuit is in the second switching state is shorter than the certain time before starting to drive the coil.

39. The transformer arrangement of claim 35,

wherein the direction of magnetization of consecutive driving the primary coil phases have opposite polarities.

40. The transformer arrangement of claim 35, wherein

the direction of magnetization of consecutive driving the primary coil phases have the same polarities for a certain number of consecutive driving the primary coil phases.

41. The transformer arrangement of claim 35, further comprising:

an amplitude detection circuit coupled to the primary coil.

42. The transformer arrangement of claim 35,

wherein the at least one transformer is a coreless transformer.