Multi-port driving and sensing circuit
A multi-port driving and sensing circuit is disclosed and provided for multi-load application. The multi-port driving and sensing circuit has a plurality of bridge switching unit and a controlling unit. A first and second upper switches of each bridge switching unit are commonly connected to a driving voltage terminal, and a first and second lower switches are commonly connected to a reference voltage terminal. When the controlling unit executes a sensing procedure, the first and second upper switches of each bridge switching unit disconnect to the driving voltage terminal and a sensing voltage signal of a load connected to each bridge switching unit is read through a signal reading unit. Therefore, when the sensing voltage signal of the load connected to one of the bridge switching units is read, the sensing voltage signal is not interfered by other sensing voltage signals of the load connected to other bridge switching units.
1 . A multi-port driving and sensing circuit comprising:
a power unit having a driving voltage terminal and a reference voltage terminal;
a plurality of bridge switching units, each of the bridge switching units has a first upper switch, a second upper switch, a first lower switch and a second lower switch, wherein the first and second lower switches are respectively connected to the first and second upper switches; wherein each of the bridge switching units further has a first sensing terminal and a second sensing terminal; wherein the first and second upper switches are connected to the driving voltage terminal and the first and second lower switches are connected to the reference voltage terminal, wherein the first sensing terminals and the second sensing terminals of the plurality of the bridge switching units are configured to respectively connect to a plurality of loads;
a signal reading unit connected to the first and second sensing terminals; and
a controlling unit connected to the bridge switching units and the signal reading unit, wherein the controlling unit has a driving procedure and a sensing procedure; wherein
when the controlling unit executes the driving procedure, the controlling unit switches one of the first and second upper switches of any one of the bridge switching units to turn on for supplying a driving voltage to the load through the driven bridge switch unit; and
when the controlling unit executes the sensing procedure, the controlling unit switches the first and second upper switches of any one of the bridge switching units to turn off to disconnect to the driving voltage terminal, and reads a sensing voltage signal of the load through the driven bridge switching unit and the signal reading unit.
2 . The multi-port driving and sensing circuit as claimed in claim 1 , wherein
the first and second sensing terminals of each bridge switching unit are respectively connected to a positive electrode and a negative electrode of the corresponding load, wherein the positive electrode is connected to the second upper switch and the negative electrode is connected to the first lower switch; and
when the controlling unit executes the sensing procedure, the controlling unit switches the first lower switch of the bridge switching unit to turn on to connect the negative electrode with the reference voltage terminal and reads the sensing voltage signal of the positive electrode of the corresponding load connected to the bridge switching unit through the signal reading unit.
3 . The multi-port driving and sensing circuit as claimed in claim 2 , wherein when the controlling unit determines that a sensing voltage of the sensing voltage signal of the positive electrode exceeds a voltage threshold, the driving procedure is executed, and then the controlling unit switches the second upper switch and the first lower switch of the bridge switching unit to turn on to provide the driving voltage to the positive electrode of the corresponding load.
4 . The multi-port driving and sensing circuit as claimed in claim 3 , wherein in the driving procedure, after the controlling unit switches the second upper switch and the first lower switch of the bridge switching unit to turn on, the controlling unit switches the second upper switch and the first lower switch to turn off and simultaneously switches the first upper switch and the second lower switch to turn on to supply the driving voltage to the negative electrode of the load.
5 . The multi-port driving and sensing circuit as claimed in claim 2 , wherein the controlling unit has a processor switching the first and second upper switches and the first and second lower switches of each bridge switching unit to turn on or off through a switch controller, wherein the processor is electrically connected to the signal reading unit and has a plurality of registers respectively connected to the first and second sensing terminals of the bridge switching units.
6 . The multi-port driving and sensing circuit as claimed in claim 5 , wherein the signal reading unit has:
a plurality of amplifying circuits respectively connected to the first and second sensing terminals of the bridge switching units; and
an analog to digital converter connected to the amplifying circuits through a multiplexer, converting the sensing voltage signals from the amplifying circuits to multiple sensing values, then outputting the sensing values to the processor, wherein the processor stores the sensing value from one of the first and second sensing terminals in one of the registers.
7 . The multi-port driving and sensing circuit as claimed in claim 6 , wherein the signal reading unit has:
an amplifier having an output terminal connected to the multiplexer; and
a multi-gain adjustment circuit connected to an input terminal of the amplifier and the processor, wherein the processor sets one of a plurality of gain values of the multi-gain adjustment circuit.
8 . The multi-port driving and sensing circuit as claimed in claim 7 , wherein the multi-gain adjustment circuit has a plurality of resistors with different resistances connected to each other in parallel, wherein one end of each of the resistors is connected to the input terminal of the amplifier through a switching circuit, wherein the switching circuit is connected to the processor and the processor selects one of the resistors to connect to the input terminal of the amplifier.
9 . The multi-port driving and sensing circuit as claimed in claim 2 , wherein
the power unit is a voltage booster;
each of the first and second upper switches and each of the first and second lower switches are MOSFET; and
the load is a piezoelectric sensor.
10 . The multi-port driving and sensing circuit as claimed in claim 9 , wherein a reference voltage of the reference voltage terminal is larger than a conducting voltage of a parasitic diode of the MOSFET.
11 . The multi-port driving and sensing circuit as claimed in claim 10 , wherein the reference voltage is not less than 1.5V and less than 5V.
12 . The multi-port driving and sensing circuit as claimed in claim 1 , wherein
the first and second sensing terminals of each bridge switching unit are respectively connected to a positive electrode and a negative electrode of the corresponding load, wherein the positive electrode is connected to the second upper switch and the negative electrode is connected to the first lower switch; and
when the controlling unit executes the sensing procedure, the controlling unit switches the second lower switch of the bridge switching unit to turn on to connect the positive electrode with the reference voltage terminal and reads the sensing voltage signal of the negative electrode of the corresponding load connected to the bridge switching unit through the signal reading unit.
13 . The multi-port driving and sensing circuit as claimed in claim 12 , wherein when the controlling unit determines that a sensing voltage of the sensing voltage signal of the negative electrode exceeds a voltage threshold, the driving procedure is executed, and then the controlling unit switches the second upper switch and the first lower switch of the bridge switching unit to turn on to provide the driving voltage to the positive electrode of the corresponding load.
14 . The multi-port driving and sensing circuit as claimed in claim 13 , wherein in the driving procedure, after the controlling unit switches the second upper switch and the first lower switch of the bridge switching unit to turn on, the controlling unit switches the second upper switch and the first lower switch to turn off and simultaneously switches the first upper switch and the second lower switch to turn on to supply the driving voltage to the negative electrode of the load.
15 . The multi-port driving and sensing circuit as claimed in claim 12 , wherein the controlling unit has a processor switching the first and second upper switches and the first and second lower switches of each bridge switching unit to turn on or off through a switch controller, wherein the processor is electrically connected to the signal reading unit and has a plurality of registers respectively connected to the first and second sensing terminals of the bridge switching units.
16 . The multi-port driving and sensing circuit as claimed in claim 12 , wherein
the power unit is a voltage booster;
each of the first and second upper switches and each of the first and second lower switches are MOSFET; and
the load is a piezoelectric sensor.
17 . The multi-port driving and sensing circuit as claimed in claim 1 , wherein
the first sensing terminal of each bridge switching unit is connected to a positive electrode of the corresponding load, wherein the positive electrode is connected to the second upper switch, and a negative electrode of the corresponding load is connected to the reference voltage terminal; and
when the controlling unit executes the sensing procedure, the controlling unit switches the first and second lower switches of the bridge switching unit to turn off and reads the sensing voltage signal of the positive electrode of the corresponding load connected to the bridge switching unit through the signal reading unit.
18 . The multi-port driving and sensing circuit as claimed in claim 17 , wherein when the controlling unit executes the driving procedure, the controlling unit switches the second upper switch of the bridge switching unit to turn on to supply the driving voltage to the positive electrode of the corresponding load.
19 . The multi-port driving and sensing circuit as claimed in claim 17 , wherein the controlling unit has a processor switching the first and second upper switches and the first and second lower switches of each bridge switching unit to turn on or off through a switch controller, wherein the processor is electrically connected to the signal reading unit and has a plurality of registers respectively connected to the first and second sensing terminals of the bridge switching units.
20 . The multi-port driving and sensing circuit as claimed in claim 17 , wherein
the power unit is a voltage booster;
each of the first and second upper switches and each of the first and second lower switches are MOSFET; and
the load is a piezoelectric sensor.