Multiplexer for a piezo ceramic identification device
View Patent ↗Provided is a multiplexer for a biometric apparatus. The multiplexer includes a plurality of first conductors coupled to the first ends of piezo ceramic elements in corresponding rows and a plurality of first switches each of which is coupled to a respective one of the first conductors and a plurality of second conductors coupled to the second ends of piezo ceramic elements in corresponding columns. The multiplexer also includes a plurality of second switches each of which is coupled to a respective one of the second conductors. The first conductors are approximately orthogonal to the second conductors, and the first switches are controlled to couple a signal output from an output port of the signal generator to a particular piezo ceramic element of the at least twenty five thousand piezo ceramic elements. The second switches are controlled to couple a signal associated with the particular piezo ceramic element of the at least twenty five thousand piezo ceramic elements to an input port of the processor.
1. A multiplexer, comprising:
a plurality of first conductors coupled to first ends of piezo ceramic elements in corresponding rows;
a plurality of first switches each of which is coupled to a respective one of the first conductors;
a plurality of second conductors coupled to second ends of piezo ceramic elements in corresponding columns; and
a plurality of second switches each of which is coupled to a respective one of the second conductors,
wherein the first conductors are approximately orthogonal to the second conductors, and
wherein the first switches are controlled to couple a signal output from an output port of the signal generator to a particular piezo ceramic element of the piezo ceramic elements, and
wherein the second switches are controlled to couple a signal associated with the particular piezo ceramic element to an input port of the processor.
2. The multiplexer of claim 1 , wherein each of the first switches and the second switches is a three-way switch.
3. The multiplexer of claim 2 , wherein each of the first switches connects one of the first conductors to one of an input of the signal generator, a high impedance open node, and a low impedance ground node.
4. The multiplexer of claim 2 , wherein each of the second switches connects one of the second conductors to one of a processor, a high impedance open node, and a low impedance ground node.
5. The multiplexer of claim 1 , further comprising:
a shift register coupled to the first switches and configured to control the position thereof.
6. The multiplexer of claim 5 , further comprising:
a controller coupled to the shift register and configured to control operation of the shift register.
7. The multiplexer of claim 6 , further comprising:
another shift register coupled to the second switches and configured to control the position thereof.
8. The multiplexer of claim 7 , wherein the controller is coupled to the another shift register and is configured to control the operation thereof.
9. The multiplexer of claim 1 , wherein the first conductors and the second conductors are formed using a vacuum deposition process.
10. The multiplexer of claim 1 , wherein the first conductors and the second conductors are formed using a lithography process.
11. The multiplexer of claim 1 , wherein the first switches comprise at least two separate integrated circuit (IC) chips.
12. The multiplexer of claim 11 , wherein the second switches comprise at least two separate IC chips.
13. A multiplexer comprising:
a plurality of first conductors each coupled to a first end of Y of piezo ceramic elements;
a plurality of second conductors each coupled to a second end of X of the piezo ceramic elements;
a plurality of first switches coupled to the first conductors;
a plurality of second switches coupled to the second conductors;
a first shift register coupled to the first switches and configured to control the position thereof;
a second shift register coupled to the second switches and configured to control the position thereof; and
a controller coupled to the first and second shift registers and configured to control the first and second shift registers.
14. The multiplexer of claim 13 , wherein each of the first conductors is approximately orthogonal to each of the second conductors.
15. The multiplexer of claim 13 , wherein the first switches are controlled to couple an output port of a signal generator to a respective one of the piezo ceramic elements.
16. The multiplexer of claim 15 , wherein the second switches are controlled to couple the respective one of the piezo ceramic elements to an input port of a processor.
17. The multiplexer of claim 13 , wherein each of the first switches and the second switches is a three-way switch.
18. The multiplexer of claim 17 , wherein each of the first switches connects one of the first conductors to one of an input port of a signal generator, a high impedance open node, and a low impedance ground node.
19. The multiplexer of claim 18 , wherein each of the second switches connects one of the second conductors to one of an input port of a processor, a high impedance open node, and a low impedance ground node.
20. The multiplexer of claim 13 , wherein each of the first conductors and the second conductors has a width of less than about one hundred microns.