Fingerprint sensing chip and terminal device
A fingerprint sensing chip and a terminal device are provided. The fingerprint sensing chip includes a first signal, a second signal and a driving signal. The second signal is generated based on the first signal, and the driving signal is generated by performing a ground raise process on the second signal. The driving signal is used to provide a driving voltage for fingerprint sensing.
1. A fingerprint sensing chip, comprising:
a first signal,
a second signal, and
a driving signal,
wherein the second signal is generated based on the first signal, and the driving signal is generated by performing a ground raise process on the second signal; and
the driving signal is used to provide a driving voltage for fingerprint sensing;
wherein:
the fingerprint chip further comprises a third signal;
the driving signal is obtained by performing a positive ground raise process on the second signal;
a voltage of the third signal ranges from 0 to a first positive voltage;
a voltage of the first signal ranges from 0 to a second positive voltage;
a voltage of the second signal ranges from 0 to a third positive voltage;
the third signal, the second signal, the driving signal and the first signal share a P-type substrate; and the P-type substrate is connected to ground GND of the fingerprint sensing chip;
the third signal is a low potential signal generated by a buck circuit in the fingerprint sensing chip; and
the second signal is generated by a booster circuit based on the first signal.
2. The fingerprint sensing chip according to claim 1 , wherein the third signal, the second signal and the driving signal are all periodically changing signals.
3. The fingerprint sensing chip according to claim 2 , wherein the third signal, the second signal and the driving signal are all square wave signals having same periods and same frequencies.
4. A terminal device, comprising:
a power supply, and
the fingerprint sensing chip according to claim 1 ,
wherein the power supply is configured to supply power to the fingerprint sensing chip;
the fingerprint sensing chip is configured to sense a fingerprint.
5. The terminal device according to claim 4 , wherein the third signal, the second signal and the driving signal are all periodically changing signals.
6. The terminal device according to claim 5 , wherein the third signal, the second signal and the driving signal are all square wave signals having same periods and same frequencies.
7. A fingerprint sensing chip, comprising:
a first signal,
a second signal, and
a driving signal,
wherein the second signal is generated based on the first signal, and the driving signal is generated by performing a ground raise process on the second signal; and
the driving signal is used to provide a driving voltage for fingerprint sensing;
wherein the fingerprint chip further comprises a third signal;
the third signal is a low potential signal generated by a buck circuit in the fingerprint sensing chip; and
the second signal is generated by a booster circuit based on the first signal;
wherein the driving signal is obtained by performing a negative ground raise process on the second signal.
8. The fingerprint sensing chip according to claim 7 , wherein
a voltage of the third signal ranges from 0 to a first positive voltage;
a voltage of the first signal ranges from 0 to a second positive voltage;
a voltage of the second signal ranges from 0 to a negative voltage; and
a low level of the driving signal is equal to a level of the second signal, and a high level of the driving signal is higher than the low level of the driving signal by a predetermined voltage.
9. The fingerprint sensing chip according to claim 7 , wherein the third signal, the second signal, the driving signal and the first signal share a P-type substrate; and
the P-type substrate is connected to a low level of the driving signal, and a voltage of the P-type substrate varies with a voltage of the driving signal.
10. A terminal device, comprising:
a power supply, and
the fingerprint sensing chip according to claim 7 ,
wherein the power supply is configured to supply power to the fingerprint sensing chip;
the fingerprint sensing chip is configured to sense a fingerprint;
wherein the driving signal is obtained by performing a negative ground raise process on the second signal.
11. The terminal device according to claim 10 , wherein
a voltage of the third signal ranges from 0 to a first positive voltage;
a voltage of the first signal ranges from 0 to a second positive voltage;
a voltage of the second signal ranges from 0 to a negative voltage; and
a low level of the driving signal is equal to a level of the second signal, and a high level of the driving signal is higher than the low level of the driving signal by a predetermined voltage.
12. The terminal device according to claim 10 , wherein the third signal, the second signal, the driving signal and the first signal share a P-type substrate; and
the P-type substrate is connected to a low level of the driving signal, and a voltage of the P-type substrate varies with a voltage of the driving signal.
13. The terminal device according to claim 10 , wherein the third signal, the second signal and the driving signal are all periodically changing signals.
14. The terminal device according to claim 13 , wherein the third signal, the second signal and the driving signal are all square wave signals having same periods and same frequencies.
15. The fingerprint sensing chip according to claim 7 , wherein the third signal, the second signal and the driving signal are all periodically changing signals.
16. The fingerprint sensing chip according to claim 15 , wherein the third signal, the second signal and the driving signal are all square wave signals having same periods and same frequencies.