Signal isolator having bidirectional diagnostic signal exchange

1. A method, comprising:

employing first and second dies having a voltage barrier region between the first and second dies, and wherein transmit and receive paths of the first and second dies provide data transfer and bi-directional transfer of feedback and/or diagnostic signals between the first and second die; and

sending, by a transmitter on the first die, transmitter refresh signals to a receiver on the second die;

sending, by the receiver, receiver refresh signals to the transmitter in response to the transmitter refresh signals;

determining that the transmitter refresh signals have not been received by the receiver for a first period of time; and

transitioning a receiver data valid signal after determining that the transmitter refresh signals have not been received for the first period of time.

2. The method according to claim 1 , further including transitioning a transmitter data valid signal after detecting that the receiver refresh signals have not been received by the transmitter for a second period of time.

3. The method according to claim 2 , wherein the transmitter data valid signal transitions state when the transmitter has a fault.

4. The method according to claim 3 , wherein the fault comprises loss of power.

5. The method according to claim 3 , wherein the receiver data valid signal transitions state when the receiver has a fault.

6. The method according to claim 2 , wherein the transmitter data valid signal transitions state when transmit refresh signals are not received by the receiver and the receiver does not send receiver refresh signals.

7. The method according to claim 6 , further including transitioning a state of the receiver data valid signal when the transmitter refresh signals are not received by the receiver for some period of time.

8. The method according to claim 2 , further including, after a communication failure between the transmitter and the receiver, re-establishing transmission of transmitter refresh signals and receiver refresh signals.

9. The method according to claim 1 , wherein intervals between the transmitter refresh signals increase when the receiver refresh signals have not been detected by the transmitter for a period of time.

10. The method according to claim 1 , wherein the transmitter includes a transmitter transistor bridge and a transmitter coil in the first path.

11. The method according to claim 10 , wherein the receiver includes a receiver sensing element in the first path coupled with the transmitter coil.

12. The method according to claim 11 , wherein the receiver includes a receiver transistor bridge and a receiver coil.

13. The method according to claim 12 , wherein the transmitter further includes a transmitter sensing element coupled to the receiver coil.

14. The method according to claim 1 , wherein the transmit refresh signals are sent in the absence of data to transfer.

15. A signal isolator IC package, comprising:

first and second dies having a voltage barrier region between the first and second dies, and wherein transmit and receive paths of the first and second dies provide bi-directional data transfer between the first and second; and

a diagnostic module comprising a first diagnostic module on the first die and a second diagnostic module on the second die, wherein the diagnostic module is configured to:

send, by a transmitter on the first die, transmitter refresh signals to a receiver on the second die;

send, by the receiver, receiver refresh signals to the transmitter in response to the transmitter refresh signals;

determine that the transmitter refresh signals have not been received by the receiver for a first period of time; and

transition a receiver data valid signal after determining that the transmitter refresh signals have not been received for the first period of time.

16. The IC package according to claim 15 , wherein the diagnostic module is further configured to transition a transmitter data valid signal after detecting that the receiver refresh signals have not been received by the transmitter for a second period of time.

17. The IC package according to claim 16 , wherein the transmitter data valid signal transitions state when the transmitter has a fault.

18. The IC package according to claim 16 , wherein the transmitter data valid signal transitions state when transmit refresh signals are not received by the receiver and the receiver does not send receiver refresh signals.

19. The IC package according to claim 15 , wherein intervals between the transmitter refresh signals increase when the receiver refresh signals have not been detected by the transmitter for a period of time.

20. The IC package according to claim 15 , further including transitioning a state of the receiver data valid signal when the transmitter refresh signals are not received by the receiver for some period of time.

21. The IC package according to claim 15 , further including, after a communication failure between the transmitter and the receiver, re-establishing transmission of transmitter refresh signals and receiver refresh signals.

22. The IC package according to claim 15 , wherein the transmitter includes a transmitter transistor bridge and a transmitter coil in the first path.

23. The IC package according to claim 22 , wherein the receiver includes a receiver sensing element in the first path coupled with the transmitter coil.

24. The IC package according to claim 23 , wherein the receiver includes a receiver transistor bridge and a receiver coil.

25. The IC package according to claim 24 , wherein the transmitter further includes a transmitter sensing element coupled to the receiver coil.