Microelectromechanical systems (MEMS) switching circuit and related apparatus
A microelectromechanical systems (MEMS) switching circuit and related apparatus is provided. A MEMS apparatus includes a MEMS switching circuit and a control circuit. The MEMS switching circuit includes a first number of MEMS switches, each configured to close and open based on a high driving voltage and a low driving voltage, respectively. The MEMS switching circuit includes a MEMS-based driver circuit configured to receive a second number of control signals that collectively identify a selected MEMS switch among the first number of MEMS switches. Accordingly, the MEMS-based driver circuit decodes the second number of control signals and causes the selected MEMS switch to close. By using a lesser number of control signals to control a larger number of MEMS switches, it may be possible to reduce control lines between the control circuit and the MEMS switching circuit, thus helping to reduce routing complexity and footprint of the MEMS apparatus.
1. A microelectromechanical systems (MEMS) switching circuit comprising:
a first number of MEMS switches each configured to close and open in response to receiving a high driving voltage and a low driving voltage, respectively; and
a MEMS-based driver circuit coupled to the first number of MEMS switches and configured to:
receive a second number of control signals configured to collectively identify a selected MEMS switch among the first number of MEMS switches;
decode the second number of control signals to determine the selected MEMS switch; and
provide the high driving voltage to the selected MEMS switch to close the selected MEMS switch.
2. The MEMS switching circuit of claim 1 wherein the second number of control signals is smaller than the first number of MEMS switches.
3. The MEMS switching circuit of claim 1 wherein the second number of control signals to the-power-of-two is greater than or equal to the first number of MEMS switches.
4. The MEMS switching circuit of claim 1 wherein the MEMS-based driver circuit is further configured to receive and provide a direct current (DC) voltage to the selected MEMS switch as the high driving voltage.
5. The MEMS switching circuit of claim 1 wherein the MEMS-based driver circuit comprises a first number of MEMS-based decoders coupled to the first number of MEMS switches, respectively, wherein the first number of MEMS-based decoders quantitatively equals the first number of MEMS switches and are configured to:
decode the second number of control signals to determine the selected MEMS switch; and
provide the high driving voltage to the selected MEMS switch to close the selected MEMS switch.
6. The MEMS switching circuit of claim 5 wherein the second number of control signals is further configured to collectively define a first number of binary codewords uniquely identifying the first number of MEMS-based decoders, respectively, wherein each of the first number of binary codewords comprises one or more binary ones (1s) corresponding to assertions of one or more of the second number of control signals.
7. The MEMS switching circuit of claim 6 wherein each of the first number of MEMS-based decoders comprises a second number of MEMS switches arranged in accordance to a respective binary codeword among the first number of binary codewords, wherein the second number of MEMS switches quantitatively equals the second number of control signals.
8. The MEMS switching circuit of claim 6 wherein:
the second number of control signals is further configured to collectively represent a selected binary codeword among the first number of binary codewords to uniquely identify a selected MEMS-based decoder among the first number of MEMS-based decoders; and
the selected MEMS-based decoder is configured to:
decode the second number of control signals to determine the selected MEMS switch; and
provide the high driving voltage to the selected MEMS switch to close the selected MEMS switch.
9. The MEMS switching circuit of claim 8 further comprising:
a first number of MEMS shunt switches coupled to the first number of MEMS switches, respectively, wherein each of the first number of MEMS shunt switches is configured to close and open in response to receiving the high driving voltage and the low driving voltage, respectively; and
a first number of MEMS-based inverters coupled to the first number of MEMS-based decoders, respectively, wherein each of the first number of MEMS-based inverters is configured to:
provide the low driving voltage to open a coupled MEMS shunt switch among the first number of MEMS shunt switches in response to a coupled MEMS-based decoder among the first number of MEMS-based decoders outputting the high driving voltage; and
provide the high driving voltage to close the coupled MEMS shunt switch in response to the coupled MEMS-based decoder outputting the low driving voltage.
10. A microelectromechanical systems (MEMS) apparatus comprising:
a MEMS switching circuit comprising;
a first number of MEMS switches each configured to close and open in response to receiving a high driving voltage and a low driving voltage, respectively; and
a MEMS-based driver circuit coupled to the first number of MEMS switches and configured to:
receive a second number of control signals configured to collectively identify a selected MEMS switch among the first number of MEMS switches;
decode the second number of control signals to determine the selected MEMS switch; and
provide the high driving voltage to the selected MEMS switch to close the selected MEMS switch; and
a control circuit coupled to the MEMS-based driver circuit and configured to provide the second number of control signals to the MEMS-based driver circuit.
11. The MEMS apparatus of claim 10 comprising:
a first semiconductor die comprising the MEMS switching circuit; and
a second semiconductor die comprising the control circuit.
12. The MEMS apparatus of claim 10 wherein:
the control circuit is further configured to:
determine the selected MEMS switch among the first number of MEMS switches to be closed;
generate the second number of control signals to collectively identify the selected MEMS switch; and
provide the second number of control signals and a direct current (DC) voltage to the MEMS-based driver circuit; and
the MEMS-based driver circuit is further configured to provide the DC voltage to the selected MEMS switch as the high driving voltage.
13. The MEMS apparatus of claim 10 wherein the second number of control signals is smaller than the first number of MEMS switches.
14. The MEMS apparatus of claim 10 wherein the second number of control signals to the-power-of-two is greater than or equal to the first number of MEMS switches.
15. The MEMS apparatus of claim 10 wherein the MEMS-based driver circuit comprises a first number of MEMS-based decoders coupled to the first number of MEMS switches, respectively, wherein the first number of MEMS-based decoders quantitatively equals the first number of MEMS switches and are configured to:
decode the second number of control signals to determine the selected MEMS switch; and
provide the high driving voltage to the selected MEMS switch to close the selected MEMS switch.
16. The MEMS apparatus of claim 15 wherein the control circuit is further configured to generate the second number of control signals to collectively define a first number of binary codewords uniquely identifying the first number of MEMS-based decoders, respectively, wherein each of the first number of binary codewords comprises one or more binary ones (1s) corresponding to assertions of one or more of the second number of control signals.
17. The MEMS apparatus of claim 16 wherein each of the first number of MEMS-based decoders comprises a second number of MEMS switches arranged in accordance to a respective binary codeword among the first number of binary codewords, the second number of MEMS switches quantitatively equal the second number of control signals.
18. The MEMS apparatus of claim 16 wherein:
the second number of control signals is further configured to collectively represent a selected binary codeword among the first number of binary codewords to uniquely identify a selected MEMS-based decoder among the first number of MEMS-based decoders; and
the selected MEMS-based decoder is configured to:
decode the second number of control signals to determine the selected MEMS switch; and
provide the high driving voltage to the selected MEMS switch to close the selected MEMS switch.
19. The MEMS apparatus of claim 18 further comprising:
a first number of MEMS shunt switches coupled to the first number of MEMS switches, respectively, wherein each of the first number of MEMS shunt switches is configured to close and open in response to receiving the high driving voltage and the low driving voltage, respectively; and
a first number of MEMS-based inverters coupled to the first number of MEMS-based decoders, respectively, wherein each of the first number of MEMS-based inverters is configured to:
provide the low driving voltage to open a coupled MEMS shunt switch among the first number of MEMS shunt switches in response to a coupled MEMS-based decoder among the first number of MEMS-based decoders outputting the high driving voltage; and
provide the high driving voltage to close the coupled MEMS shunt switch in response to the coupled MEMS-based decoder outputting the low driving voltage.
20. The MEMS apparatus of claim 19 wherein each of the first number of MEMS-based inverters comprises a MEMS switch configured to be closed in response to the coupled MEMS-based decoder outputting the high driving voltage and opened in response to the coupled MEMS-based decoder outputting the low driving voltage.