Galvanic isolation circuitry and associated low power wakeup methods
Disclosed herein are methods, systems, and devices for providing galvanic isolation and low power wakeup of circuitry. According to one embodiment, an apparatus includes first isolation circuitry, second isolation circuitry, and first control circuitry. The first isolation circuitry includes a first primary interface and a first secondary interface. The first primary interface is galvanically isolated from the first secondary interface. The second isolation circuitry includes a second primary interface and a second secondary interface. The second primary interface is galvanically isolated from the second secondary interface. The first control circuitry is electrically coupled with the first secondary interface and the second secondary interface. The first control circuitry is configured to transition the apparatus from a sleep state to a wake state upon receiving a wake signal and the first isolation circuitry is configured to provide the wake signal to the first control circuitry via the first secondary interface.
1. An apparatus comprising:
first isolation circuitry having a first primary interface and a first secondary interface, wherein the first primary interface is galvanically isolated from the first secondary interface;
second isolation circuitry having a second primary interface and a second secondary interface, wherein the second primary interface is galvanically isolated from the second secondary interface; and
first control circuitry electrically coupled with the first secondary interface and the second secondary interface, wherein:
the first control circuitry is configured to transition the apparatus from a sleep state to a wake state upon receiving a wake signal; and
the first isolation circuitry is configured to provide the wake signal to the first control circuitry via the first secondary interface.
2. The apparatus of claim 1 , wherein the first control circuitry is configured to receive a first digital communication signal from second control circuitry via the second isolation circuitry.
3. The apparatus of claim 2 , wherein the first control circuitry is further configured to transmit a second digital communication signal to the second control circuitry via the second isolation circuitry.
4. The apparatus of claim 2 , wherein the first control circuitry is galvanically isolated from the second control circuitry.
5. The apparatus of claim 2 further comprising detection circuitry electrically coupled between the first primary interface and the second primary interface.
6. The apparatus of claim 5 , wherein the detection circuitry is configured to provide the wake signal to the first primary interface upon detecting the first digital communication signal arriving at the second primary interface.
7. The apparatus of claim 1 , wherein the second isolation circuitry is configured to be powered down during the sleep state and powered up during the wake state.
8. The apparatus of claim 1 , wherein the first isolation circuitry comprises an optocoupler.
9. The apparatus of claim 8 , wherein the optocoupler comprises:
a pair of input terminals configured to receive the wake signal; and
an output transistor having a collector and an emitter wherein:
the collector is electrically coupled with the first control circuitry; and
the collector is configured to provide the wake signal to the first control circuitry.
10. The apparatus of claim 8 , wherein the second isolation circuitry comprises a digital isolator.
11. The apparatus of claim 1 , wherein the first isolation circuitry comprises a first transformer.
12. The apparatus of claim 11 , wherein the second isolation circuitry comprises a second transformer.
13. The apparatus of claim 1 further comprising a battery, wherein the battery is configured to power the second secondary interface of the second isolation circuitry during the wake state.
14. The apparatus of claim 1 further comprising a capacitor, wherein the capacitor is configured to power the second secondary interface of the second isolation circuitry during the wake state.
15. The apparatus of claim 1 , wherein:
the first isolation circuitry comprises a photovoltaic detector; and
the second isolation circuitry comprises an optical transceiver.
16. A method of operating an apparatus, the method comprising:
receiving a first digital communication signal, wherein the apparatus comprises:
first isolation circuitry having a first primary interface and a first secondary interface, wherein the first primary interface is galvanically isolated from the first secondary interface;
second isolation circuitry having a second primary interface and a second secondary interface, wherein the second primary interface is galvanically isolated from the second secondary interface; and
first control circuitry electrically coupled with the first secondary interface and the second secondary interface;
generating a wake signal upon receiving the first digital communication signal;
providing the wake signal to the first control circuitry using the first isolation circuitry; and
transitioning the first control circuitry from a sleep state to a wake state.
17. The method of claim 16 further comprising transitioning the second isolation circuitry from a power-down state to a power-up state upon transitioning the first control circuitry from the sleep state to the wake state.
18. The method of claim 17 further comprising providing a portion of the first digital communication signal to the first control circuitry via the second isolation circuitry.
19. The method of claim 18 , wherein the first digital communication signal comprises a first preamble and a first data packet.
20. The method of claim 19 further comprising providing a second digital communication signal from the first control circuitry to second control circuitry via the second isolation circuitry.
21. The method of claim 20 , wherein the second digital communication signal comprises a second preamble and a second data packet.
22. A method of manufacture of an apparatus, the method comprising:
installing first isolation circuitry onto a printed circuit board (PCB), wherein:
the first isolation circuitry includes a first primary interface and a first secondary interface; and
the first primary interface is galvanically isolated from the first secondary interface;
installing second isolation circuitry onto the PCB, wherein:
the second isolation circuitry includes a second primary interface and a second secondary interface; and
the second primary interface is galvanically isolated from the second secondary interface; and
installing first control circuitry onto the PCB, wherein:
the first control circuitry is electrically coupled with the first secondary interface and the second secondary interface;
the first control circuitry is configured to transition the apparatus from a sleep state to a wake state upon receiving a wake signal; and
the first isolation circuitry is configured to provide the wake signal to the first control circuitry via the first secondary interface.
23. The method of claim 22 further comprising:
installing detection circuitry onto the PCB, wherein:
the detection circuitry is electrically coupled between the first primary interface and the second primary interface; and
the detection circuitry is configured to provide a wake signal to the first primary interface upon detecting a first digital communication signal arriving at the second primary interface;
installing an isolated power source onto the PCB; and
installing a switch onto the PCB; wherein;
the switch is electrically coupled between the isolated power source and the second isolation circuitry; and
the switch is electrically coupled with the first control circuitry.