Wake-up detector
The apparatus is a wake-up circuit including a first comparator coupled to an input signal and configured to compare the input signal to a first comparison value. The wake-up circuit includes a second comparator coupled to the input signal and configured to compare the input signal to a second comparison value. The wake-up circuit further includes an exclusive OR gate. A first input of the exclusive OR gate is coupled to an output of the first comparator. A second input of the exclusive OR gate is coupled to an output of the second comparator. The wake-up circuit also includes a tunable charge pump coupled to an output of the exclusive OR gate and configured to convert a signal from the exclusive OR gate to a DC value to wake up a circuit being monitored.
1. An apparatus to wake up a slave circuit in a system, the apparatus comprising:
a coupler configured to couple a remote wake-up signal between a master circuit and the slave circuit using at least one connection of a fixed set of cable connections, the at least one connection further coupling a second signal between the master circuit and the slave circuit;
a selection component configured to select, at the slave circuit, the remote wake-up signal from a control signal, an intermediate frequency (IF) signal, or a local oscillator (LO) signal;
a detector configured to detect, at the slave circuit, the remote wake-up signal coupled between the master circuit and the slave circuit, wherein the detector is further configured to:
compare an input signal to a first comparison value to generate a first comparison result;
compare the input signal to a second comparison value to generate a second comparison result; and
combine the first comparison result and the second comparison result to generate a signal; and
a wake-up signal generator configured to generate a local wake-up signal at the slave circuit based on detecting the remote wake-up signal coupled between the master circuit and the slave circuit and wake up the slave circuit with the local wake-up signal.
2. The apparatus of claim 1 , wherein the second signal is coupled between the master circuit and the slave circuit for at least a period of time when the slave circuit is awake.
3. The apparatus of claim 1 , wherein the detector comprises an energy detector.
4. The apparatus of claim 1 , wherein the remote wake-up signal comprises a direct current (DC) voltage.
5. The apparatus of claim 4 , wherein the detector is further configured to detect a direct current (DC) voltage.
6. The apparatus of claim 1 , wherein the remote wake-up signal comprises the control signal.
7. The apparatus of claim 1 , wherein the remote wake-up signal comprises the IF signal.
8. The apparatus of claim 1 , wherein the remote wake-up signal comprises the LO signal.
9. The apparatus of claim 1 , wherein the control signal comprises a digital bit sequence.
10. The apparatus of claim 9 , further comprising a filter configured to filter the remote wake-up signal.
11. A method to wake up a slave circuit in a system, the method comprising:
coupling a remote wake-up signal between a master circuit and the slave circuit using at least one connection of a fixed set of cable connections, the at least one connection further coupling a second signal between the master circuit and the slave circuit;
selecting, at the slave circuit, the remote wake-up signal from a control signal, an intermediate frequency (IF) signal, or a local oscillator (LO) signal;
detecting, at the slave circuit, the remote wake-up signal coupled between the master circuit and the slave circuit, wherein the detecting comprises:
comparing an input signal to a first comparison value to generate a first comparison result;
comparing the input signal to a second comparison value to generate a second comparison result; and
combining the first comparison result and the second comparison result to generate a signal; and
generating a local wake-up signal at the slave circuit based on detecting the remote wake-up signal coupled between the master circuit and the slave circuit and wake up the slave circuit with the local wake-up signal.
12. The method of claim 11 , wherein the second signal is coupled between the master circuit and the slave circuit for at least a period of time when the slave circuit is awake.
13. The method of claim 11 , wherein detecting, at the slave circuit, the remote wake-up signal comprises detecting energy using an energy detector.
14. The method of claim 11 , wherein the remote wake-up signal comprises a direct current (DC) voltage.
15. The method of claim 14 , further comprising detecting a direct current (DC) voltage.
16. The method of claim 11 , wherein the remote wake-up signal comprises the control signal.
17. The method of claim 11 , wherein the remote wake-up signal comprises the IF signal.
18. The method of claim 11 , wherein the remote wake-up signal comprises the LO signal.
19. The method of claim 11 , wherein the control signal comprises a digital bit sequence.
20. The method of claim 19 , further comprising filtering the remote wake-up signal.
21. An apparatus to wake up a slave circuit in a system, the apparatus comprising:
means for coupling a remote wake-up signal between a master circuit and the slave circuit using at least one connection of a fixed set of cable connections, the at least one connection further coupling a second signal between the master circuit and the slave circuit;
means for selecting, at the slave circuit, the remote wake-up signal from a control signal, an intermediate frequency (IF) signal, or a local oscillator (LO) signal;
means for detecting, at the slave circuit, the remote wake-up signal coupled between the master circuit and the slave circuit, wherein the means for detecting is configured to:
compare an input signal to a first comparison value to generate a first comparison result;
compare the input signal to a second comparison value to generate a second comparison result; and
combine the first comparison result and the second comparison result to generate a signal; and
means for generating a local wake-up signal at the slave circuit based on detecting the remote wake-up signal coupled between the master circuit and the slave circuit and wake up the slave circuit with the local wake-up signal.
22. The apparatus of claim 21 , wherein the second signal is coupled between the master circuit and the slave circuit for at least a period of time when the slave circuit is awake.
23. The apparatus of claim 21 , wherein detecting, at the slave circuit, the remote wake-up signal comprises detecting energy using an energy detector.
24. The apparatus of claim 21 , wherein the remote wake-up signal comprises a direct current (DC) voltage.