AC Pulse Control of PCM Switch
Circuits and methods for increasing the long-term reliability and performance of phase change material (PCM) switches. To overcome the effects of electromigration damage of the resistive heater(s) of a PCM switch and of the PCM itself, and thus improve long-term performance and reliability, embodiments apply an AC control pulse of equal power to a conventional DC control pulse. An embodiment encompasses a PCM switch, including a PCM region including first and second signal ports configured to be coupled to a signal source; a resistive heater adjacent the PCM region and including first and second heater control signal ports; and a source of AC control pulses coupled to the first and second heater control signal ports, the AC control pulses having a first power profile to transform the PCM region into a low resistance state and a second power profile to transform the PCM region into a high resistance state.
1 . A phase change material (PCM) switch, including:
(a) a PCM region including first and second signal ports configured to be coupled to a signal source;
(b) a resistive heater adjacent the PCM region and including first and second heater control signal ports;
(c) a source of AC control pulses coupled to the first and second heater control signal ports the AC control pulses having a first power profile to transform the PCM region into a high resistance state and a second power profile to transform the PCM region into a low resistance state.
2 . The invention of claim 1 , wherein the first power profile comprises a set of high-power, short-period AC control pulses to transform the PCM region into a high resistance state.
3 . The invention of claim 1 , wherein the second power profile comprises a set of low-power, long-period AC control pulses to transform the PCM region into a low resistance state.
4 . The invention of claim 1 , wherein the first power profile comprises a first set of high-power, short-period AC control pulses to transform the PCM region into a high resistance state, and the second power profile comprises a second set of low-power, long-period AC control pulses to transform the PCM region into a low resistance state.
5 . The invention of claim 1 , wherein the AC control pulses have a rectangular waveform.
6 . The invention of claim 1 , wherein the AC control pulses have a sinusoidal waveform.
7 . The invention of claim 1 , wherein the AC control pulses have a sawtooth waveform.
8 . The invention of claim 1 , wherein the AC control pulses have a triangular waveform.
9 . The invention of claim 1 , wherein the source of AC control pulses includes an H-Bridge circuit coupled to the first and second heater control signal ports.
10 . A phase change material (PCM) switch, including:
(a) a PCM region including first and second signal ports configured to be coupled to a signal source;
(b) a resistive heater adjacent the PCM region and including first and second heater control signal ports;
(c) a source of AC control pulses coupled to the first and second heater control signal ports and configured to selectively output a first set of AC control pulses to transform the PCM region into a high resistance state and a second set of AC control pulses to transform the PCM region into a low resistance state.
11 . The invention of claim 10 , wherein the first set of AC control pulses comprises high-power, short-period AC control pulses to transform the PCM region into a high resistance state.
12 . The invention of claim 10 , wherein the second set of AC control pulses comprises low-power, long-period AC control pulses to transform the PCM region into a low resistance state.
13 . The invention of claim 10 , wherein the first set of AC control pulses comprises high-power, short-period AC control pulses to transform the PCM region into a high resistance state, and the second set of AC control pulses comprises low-power, long-period AC control pulses to transform the PCM region into a low resistance state.
14 . The invention of claim 10 , wherein the AC control pulses have a rectangular waveform.
15 . The invention of claim 10 , wherein the AC control pulses have a sinusoidal waveform.
16 . The invention of claim 10 , wherein the AC control pulses have a sawtooth waveform.
17 . The invention of claim 10 , wherein the AC control pulses have a triangular waveform.
18 . The invention of claim 10 , wherein the source of AC control pulses includes an H-Bridge circuit coupled to the first and second heater control signal ports.
19 .- 36 . (canceled)