CN101173578A - Fingerprint collecting device and its method for automatically quitting locking mode - Google Patents
Fingerprint collecting device and its method for automatically quitting locking mode Download PDFInfo
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- CN101173578A CN101173578A CNA2006100635005A CN200610063500A CN101173578A CN 101173578 A CN101173578 A CN 101173578A CN A2006100635005 A CNA2006100635005 A CN A2006100635005A CN 200610063500 A CN200610063500 A CN 200610063500A CN 101173578 A CN101173578 A CN 101173578A
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Abstract
The invention provides a fingerprint collection device and a method of automatically withdrawing the latching state. The fingerprint collection device at least comprises a semiconductor fingerprint sensor and a processor connected with the bus of the sensor. The power input end of the fingerprint collection device or of the fingerprint sensor is connected in series with an overcurrent sensor of the detecting control circuit of source current. When the latching state happens, the detecting control circuit outputs effective control signal according to the voltage variation in the overcurrent sensor, which makes the power cut off the current and cut off the electricity supply for the semiconductor fingerprint sensor and the processor, and automatically switches on the electricity supply after a period of time. The overcurrent sensor uses a PTC self-restoring fuse, which considerably induces the influence of component connection. Using the invention facilitates the fingerprint sensor to reliably and economically realize the automatic recovery of the latching state, which is easy to execute.
Description
Technical field
The present invention relates to the electrostatic discharge protective of semiconductor fingerprint sensor, relate in particular to method and circuit that this semiconductor transducer withdraws from latch mode.
Background technology
Static is widespread in nature, and can reach several thousand even volt up to ten thousand on human body, and so high electrostatic potential is very easily damaged exposed integrated circuit.Generally, the other parts of integrated circuit except that pin all insulated body are surrounded, so the electrostatic discharge event majority takes place via pin.Therefore, be not damaged in order to guarantee IC interior, general all in integrated circuit the pin place be provided with special holding circuit.And general integrated circuit all is placed in shielding case or the casing with circuit board, has reduced the generation of electrostatic discharge event on integrated circuit as much as possible.
But, for example just more and more widely be used in the semiconductor fingerprint sensor in personal information security fields such as notebook computer, desktop computer, mobile phone, mobile storage, the electrostatic influence of but having to consider for specific integrated circuit.As shown in Figure 1, the semiconductor fingerprint sensor comprises the exposed induction arrays L outside of needs, and there is the diaphragm of one deck very thin (having only several micron thickness usually) on the surface of array.As shown in Figure 2, when gathering somatic fingerprint, this induction arrays needs directly to contact with user's finger regularly.So the electrostatic potential on the human body may enter into the sensor internal circuit across the diaphragm of several micron thickness, make it enter latch mode.At this state, some parasitic transistor conductings of described circuit, thus form a lasting electric current at power supply and ground end.The existence of this electric current not only influences fingerprint sensor work, continues to burn circuit toward the contact meeting.Have only power remove just can be withdrawed from described latch mode.
In addition, in actual applications, the semiconductor fingerprint sensor is connected with other integrated circuit toward contact.After the power supply supply of turn-offing this fingerprint sensor, fingerprint sensor still might obtain to maintain the electric current of latch mode from those integrated circuits by mutual data wire.
U.S. Pat 6,661,631 disclose the technical scheme that a kind of fingerprint sensor withdraws from from latch mode automatically, be to monitor latch mode whether occurs, make sensor withdraw from latch mode by power supply that turn-offs fingerprint sensor and the data connecting line that disconnects between fingerprint sensor and controller again by the operating current that detects fingerprint sensor.Wherein, the monitoring of latch mode has utilized the series resistance in the fingerprint sensor power work loop to detect voltage, to judge whether overcurrent.
Above-mentioned the deficiencies in the prior art part is: the disconnection of data connecting line needs extra device between fingerprint sensor and the controller, especially uses bus switch, will increase the scheme cost; In addition, the described series resistance that is used for detecting overcurrent, if the resistance operating voltage range that will limit fingerprint sensor bigger than normal, but need more complicated circuit improve detection sensitivity as if less than normal, thus be difficult for reliable enforcement.
Summary of the invention
The technical problem to be solved in the present invention is at above-mentioned the deficiencies in the prior art part, and proposes a kind of method and circuit, makes the semiconductor fingerprint sensor realize at low cost recovering automatically from latch mode, and easy to implement.
For solving the problems of the technologies described above, of the present inventionly be contemplated that substantially: when detecting latch mode and take place, cut off simultaneously the power supply supply of fingerprint sensor, thereby can save bus switch with the integrated circuit that links to each other with this fingerprint sensor.In addition, utilize PTC resettable fuse resistance under over-current state to increase rapidly, and cutting off the characteristic that has low-resistance under electric current or the normal current, it is serially connected in power input makes over-current detection usefulness, can reduce element greatly and insert influence, be convenient to realize reliably the automatic recovery under the latch mode the integrated circuit power supply.
As the technical scheme that realizes the present invention's design be, a kind of method of fingerprint acquisition device automatically quitting locking mode is provided, described fingerprint acquisition device comprises semiconductor fingerprint sensor and the processor that links to each other with this sensor bus at least, especially, comprises step:
A. detect the source current of described semiconductor fingerprint sensor, or the total current of this source current and the source current sum of the some integrated circuits that are connected this semiconductor fingerprint sensor;
B. judge whether described source current or described total current surpass corresponding predetermined value, if judge that then latch mode occurs; Otherwise continuation steps A;
C. cut off the power supply that offers described semiconductor fingerprint sensor and described processor;
D. behind the predetermined time interval, the described power supply supply among the recovering step C continues steps A automatically.
Like this, can save the bus switch that between described semiconductor fingerprint sensor and described processor, is provided with, reduce and realize cost.
In the such scheme, in the described steps A, adopt at corresponding power input serial connection PTC resettable fuse and monitor described source current or described total current; Like this, after described step B judged that latch mode occurs, described PTC resettable fuse two ends became big voltage drop and are used for the effective control signal of triggering for generating, offer the power remove circuit and carry out step C.
In the such scheme, after power supply was cut off among the step C, the conducting resistance of described PTC resettable fuse was recovered normal low-resistance, and both end voltage is fallen and diminished, thereby behind the predetermined time interval described in the time-delay step D, made the control signal auto-idled recover the power supply supply.
Like this, can reduce the influence of detecting element to circuit supply stream.
As the technical scheme that realizes the present invention's design still, provide a kind of fingerprint acquisition device, comprise semiconductor fingerprint sensor and the processor that links to each other with this sensor bus at least, and source current detects control circuit, power remove circuit; Especially, described source current detects control circuit and comprises the overcurrent inductor, this overcurrent inductor is serially connected in the input of the power supply that offers described semiconductor fingerprint sensor and described processor, or is serially connected in the input of the power supply that offers described semiconductor fingerprint sensor; Described detection control circuit is also exported a control signal; Described power remove circuit comprises at least one transistor, and switch ends is serially connected in the input of the power supply that offers described semiconductor fingerprint sensor and described processor; Or comprise that at least two transistors, switch ends are serially connected in the input and the input that offers the power supply of described processor of the power supply that offers described semiconductor fingerprint sensor respectively; Each described transistorized control end receives described control signal.
In the such scheme, described overcurrent inductor is the PTC resettable fuse, and when latch phenomenon occurring, this fuse becomes big conducting resistance rapidly makes the pressure drop on the fuse become big; After the power supply input of described semiconductor fingerprint sensor was turned off, this fuse recovered normal low-resistance.
In the such scheme, described source current detects control circuit and also comprises the control signal generator, receives change in pressure drop signal on the described overcurrent inductor by voltage detecting circuit, produces described control signal; Described source current detects control circuit and also comprises timing unit, and the timing signal of described control signal generator is sent in output, and logical validity time of described control signal is controlled in the preset time scope.
In the such scheme, described control signal generator comprises a transistor M1, its base stage and emitter stage, or grid and source electrode are in parallel with described PTC resettable fuse by being electrically connected; Resistance R 2 ground connection are passed through in colelctor electrode or drain electrode, and described control signal is provided.
In the such scheme, described timing unit comprises the capacitor C 1 and the resistance R 1 of series connection, this series arm is in parallel with described PTC resettable fuse, the emitter stage of described transistor M1 or source electrode connect an end of described PTC resettable fuse, and base stage or grid are electrically connected the other end of this PTC resettable fuse by the tie point of described capacitor C 1 and resistance R 1.
Adopt above-mentioned each technical scheme, product is simple, has easier enforcement, more reliable advantage, thereby has reduced electrostatic hazard.
Description of drawings
Fig. 1 is existing semiconductor fingerprint sensor generalized section
Fig. 2 is to use the schematic diagram of Fig. 1 sensor acquisition fingerprint
Fig. 3 is the inventive method and installs the first embodiment schematic diagram
Fig. 4 is the inventive method and installs the second embodiment schematic diagram
Fig. 5 is the structured flowchart that source current of the present invention detects control circuit
Fig. 6 is based on Fig. 5 physical circuit embodiment of Fig. 4
The specific embodiment
Below, the most preferred embodiment shown in is further set forth the present invention in conjunction with the accompanying drawings.
Fingerprint acquisition device of the present invention as shown in Figure 3, at least comprise semiconductor fingerprint sensor and the processor that links to each other with this sensor bus, wherein fingerprint sensor is gathered user's fingerprint image and is converted data message to, the work of processor control fingerprint sensor, and receive the fingerprint image data that it collects.Comprise that also source current detects control circuit, and the power remove circuit that comprises switch SW 1 or SW2.Among the present invention, the method for this device automatically quitting locking mode will comprise step:
A. detect the source current of described semiconductor fingerprint sensor, can be as shown in Figure 3, two test sides (1,2) that described source current is detected control circuit are serially connected in the input of the power supply that offers described semiconductor fingerprint sensor and bring in realization;
B. judge whether described source current surpasses corresponding predetermined value, if judge that then latch mode occurs; Otherwise continuation steps A;
C. cut off the power supply that offers described semiconductor fingerprint sensor and described processor;
D. behind the predetermined time interval, the described power supply supply among the recovering step C continues steps A automatically.
Wherein step C and D, the control signal of the output of current detection control circuit control end (3) shown in can utilizing, control is serially connected in the switch SW 1 of described semiconductor fingerprint sensor and processor power supply input respectively and the folding of SW2 realizes.Like this, when fingerprint sensor in use runs into electrostatic discharge event and enters latch mode, when consuming bigger source current, this state will be detected and gauge tap SW1, SW2 by current detection control circuit, make the power supply source of its disconnection process device and fingerprint sensor earlier, then make it connect power supply again to resume work.
Certainly, the current detecting in the above-mentioned correlation step can also be as shown in Figure 4, detects with the total current of the source current sum of the processor that is connected this fingerprint sensor and judge at the fingerprint sensor source current.Described source current detects the input that the control control circuit is serially connected in the power supply that offers described semiconductor fingerprint sensor and described processor, like this, only need use a total power switch SW3 to turn-off or connect described power supply source.
Described switch SW 1～SW3 can realize with transistor.At the embodiment of Fig. 3, described power remove circuit comprises at least two transistors like this, and switch ends is serially connected in the input of the power supply that offers described semiconductor fingerprint sensor respectively and offers the input of the power supply of described processor; At the embodiment of Fig. 4, described power remove circuit comprises at least one transistor, and switch ends is serially connected in the input of the power supply that offers described semiconductor fingerprint sensor and described processor; Each described transistorized control end receives the control signal from current detection control circuit.Described transistor comprises bipolar transistor or FET.
Insert the influence of current detection control circuit in order to reduce to each integrated circuit power supply stream, the inventive method can be as shown in Figure 5, this detection control circuit comprises (between described two test sides, thereby quilt) be serially connected in the overcurrent inductor that corresponding power input carries out the overcurrent monitoring, this overcurrent inductor can adopt PTC (Positive TemperatureCoefficient, that is positive temperature coefficient) resettable fuse.Like this, after described step B judges that latch mode occurs, described PTC resettable fuse two ends become rapidly big conducting resistance makes the pressure drop on the fuse become big, and this voltage drop can be used for the described control signal of triggering for generating, offers the power remove circuit and carries out step C.After treating that described line related is cut off, the conducting resistance of described PTC resettable fuse is recovered normal low-resistance, and both end voltage is fallen and diminished, thereby the predetermined time interval described in the time-delay step D calculates, and makes the control signal auto-idled recover the power supply supply.
Correspondingly, shown in this Fig. 5 frame of broken lines, the source current of fingerprint acquisition device of the present invention detects control circuit and also comprises the control signal generator, be electrically connected the change in pressure drop signal that receives on the described overcurrent inductor (for example PTC resettable fuse) by voltage detecting circuit, produce described control signal, detect the control end output of control circuit by this source current; Also comprise timing unit, the timing signal of described control signal generator is sent in output, and logical validity time of described control signal is controlled in the preset time scope.This timing unit can receive change in pressure drop signal on the described PTC resettable fuse (as dotted line 1. shown in), also can receive described power remove circuit output signal (as dotted line 2. shown in), trigger or start time-delay and calculate, after reaching the scheduled time, described timing signal makes described control signal logic upset.
Fig. 6 is to be the specific embodiment that example realizes foregoing circuit with Fig. 4.Wherein, the power remove circuit is realized with PMOS pipe M2.Described timing unit comprises the capacitor C 1 and the resistance R 1 of series connection, and this series arm is in parallel with described PTC resettable fuse F1.The control signal generator comprises that (with PMOS is example to transistor M1, do not get rid of and use the PNP triode), its grid and source electrode (or base stage and emitter stage) are in parallel with described fuse F1 by being electrically connected, promptly, source electrode connects the end of described fuse F1, and grid is electrically connected the other end of this fuse F1 by the tie point of described capacitor C 1 and resistance R 1; Resistance R 2 ground connection are passed through in its colelctor electrode or drain electrode, and the grid of described control signal toward described transistor M2 is provided.Like this, under the normal condition, the conducting resistance of PTC resettable fuse F1 is very little, and the pressure drop at two ends is close to zero, and the voltage at capacitor C 1 two ends also is close to zero, thereby PMOS pipe M1 ends, and the current potential of node C is a low level, PMOS pipe M2 conducting.Power supply is powered to processor and fingerprint sensor through fuse F1, transistor M2.
When electrostatic discharge event caused latch mode to occur, because of overcurrent, described PTC resettable fuse F1 entered guard mode, and it is big that conducting resistance becomes rapidly, and the pressure drop at two ends also becomes greatly, makes the current potential of node A reduce rapidly.Enter cut-off state in order to control transistor M2 fast, also comprise the Schottky diode D1 (pressure drop is very little, has only 0.2V usually) that is connected in parallel on the described resistance R 1 in the present embodiment, its negative electrode connects the end of described PTC resettable fuse F1; The current potential of Node B also reduces rapidly like this, and described PMOS manages the M1 conducting, draws high the current potential of node C, and PMOS pipe M2 is ended, and the power supply source of processor and fingerprint sensor is cut off.Therefore, associated pathway (power line, the data connecting line) signal that maintains described fingerprint sensor latch mode all interrupts, and has protected fingerprint sensor effectively and has made it withdraw from latch mode.
After described power supply was cut off, described PTC resettable fuse F1 returned to normal low on-resistance state, and node A reverts to high potential, and is higher than the current potential of Node B, and diode D1 is in cut-off state.Capacitor C 1 is slowly discharged by resistance R 1 and fuse F1, after the scheduled time (making fingerprint sensor withdraw from latch mode), PMOS pipe M1 recovers cut-off state, PMOS pipe M2 conducting once more, thereby the power supply of described processor and fingerprint sensor is restored, and works on power automatically.
Timing unit in the present embodiment can also adopt other timing ic, and for example trigger replaces, and the control signal generating unit also can be equal to replacement with other prior art, does not give unnecessary details at this.
The foregoing description has been realized withdrawing from automatically of latch mode reliably through verification experimental verification, and have circuit simple, low-cost, does not almost have a secondary advantage that influences.
Claims (11)
1. the method for a fingerprint acquisition device automatically quitting locking mode, described fingerprint acquisition device comprise semiconductor fingerprint sensor and the processor that links to each other with this sensor bus at least, it is characterized in that, comprise step:
A. detect the source current of described semiconductor fingerprint sensor, or the total current of this source current and the source current sum of the processor that is connected this semiconductor fingerprint sensor;
B. judge whether described source current or described total current surpass corresponding predetermined value, if judge that then latch mode occurs; Otherwise continuation steps A;
C. cut off the power supply that offers described semiconductor fingerprint sensor and described processor;
D. behind the predetermined time interval, the described power supply supply among the recovering step C continues steps A automatically.
2. according to the method for the described fingerprint acquisition device automatically quitting locking mode of claim 1, it is characterized in that:
In the described steps A, adopt at corresponding power input serial connection PTC resettable fuse and monitor described source current or described total current; Like this, after described step B judged that latch mode occurs, described PTC resettable fuse two ends became big voltage drop and are used for the effective control signal of triggering for generating, offer the power remove circuit and carry out step C.
3. according to the method for the described fingerprint acquisition device automatically quitting locking mode of claim 2, it is characterized in that:
Described power remove circuit comprises at least one transistor, and switch ends is serially connected in the input of the power supply that offers described semiconductor fingerprint sensor and described processor; Or comprise that at least two transistors, switch ends are serially connected in the input and the input that offers the power supply of described processor of the power supply that offers described semiconductor fingerprint sensor respectively;
Each described transistorized control end receives described control signal.
4. according to the method for the described fingerprint acquisition device automatically quitting locking mode of claim 2, it is characterized in that:
After power supply was cut off among the step C, the conducting resistance of described PTC resettable fuse was recovered normal low-resistance, and both end voltage is fallen and diminished, thereby behind the predetermined time interval described in the time-delay step D, made the control signal auto-idled recover the power supply supply.
5. a fingerprint acquisition device comprise semiconductor fingerprint sensor and the processor that links to each other with this sensor bus at least, and source current detects control circuit, power remove circuit; It is characterized in that:
Described source current detects control circuit and comprises the overcurrent inductor, this overcurrent inductor is serially connected in the input of the power supply that offers described semiconductor fingerprint sensor and described processor, or is serially connected in the input of the power supply that offers described semiconductor fingerprint sensor; Described detection control circuit is also exported a control signal;
Described power remove circuit comprises at least one transistor, and switch ends is serially connected in the input of the power supply that offers described semiconductor fingerprint sensor and described processor; Or comprise that at least two transistors, switch ends are serially connected in the input and the input that offers the power supply of described processor of the power supply that offers described semiconductor fingerprint sensor respectively; Each described transistorized control end receives described control signal.
6. fingerprint acquisition device according to claim 5 is characterized in that:
Described overcurrent inductor is the PTC resettable fuse, and when latch phenomenon occurring, this fuse becomes big conducting resistance rapidly makes the pressure drop on the fuse become big; After the power supply input of described semiconductor fingerprint sensor was turned off, this fuse recovered normal low-resistance.
7. according to claim 5 or 6 described fingerprint acquisition devices, it is characterized in that:
Described source current detects control circuit and also comprises the control signal generator, receives change in pressure drop signal on the described overcurrent inductor by voltage detecting circuit, produces described control signal;
Described source current detects control circuit and also comprises timing unit, and the timing signal of described control signal generator is sent in output, and logical validity time of described control signal is controlled in the preset time scope.
8. fingerprint acquisition device according to claim 7 is characterized in that:
Described timing unit receives the change in pressure drop signal on the described overcurrent inductor, or receives the output signal of described power remove circuit, and the time-delay that starts the scheduled time is calculated.
9. fingerprint acquisition device according to claim 7 is characterized in that:
Described control signal generator comprises transistor M1, its base stage and emitter stage, or grid and source electrode are in parallel with described PTC resettable fuse by being electrically connected; Resistance R 2 ground connection are passed through in colelctor electrode or drain electrode, and described control signal is provided.
10. fingerprint acquisition device according to claim 9 is characterized in that:
Described timing unit comprises the capacitor C 1 and the resistance R 1 of series connection, this series arm is in parallel with described PTC resettable fuse, the emitter stage of described transistor M1 or source electrode connect an end of described PTC resettable fuse, and base stage or grid are electrically connected the other end of this PTC resettable fuse by the tie point of described capacitor C 1 and resistance R 1.
11. fingerprint acquisition device according to claim 10 is characterized in that:
Described source current detects control circuit and also comprises Schottky diode D1, is connected in parallel on the described resistance R 1, and its negative electrode connects an end of described PTC resettable fuse.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2006100635005A CN101173578A (en) | 2006-11-01 | 2006-11-01 | Fingerprint collecting device and its method for automatically quitting locking mode |
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| Application Number | Priority Date | Filing Date | Title |
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| CNA2006100635005A CN101173578A (en) | 2006-11-01 | 2006-11-01 | Fingerprint collecting device and its method for automatically quitting locking mode |
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| CN101173578A true CN101173578A (en) | 2008-05-07 |
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| CNA2006100635005A Pending CN101173578A (en) | 2006-11-01 | 2006-11-01 | Fingerprint collecting device and its method for automatically quitting locking mode |
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Cited By (8)
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| CN105608413A (en) * | 2014-11-14 | 2016-05-25 | 深圳市汇顶科技股份有限公司 | Latch recovery mechanism of fingerprint sensor based on state monitoring and handshake |
| TWI559232B (en) * | 2014-12-15 | 2016-11-21 | 義隆電子股份有限公司 | Sensing method and circuit of fingerprint sensor |
| US9613247B2 (en) | 2014-12-15 | 2017-04-04 | Elan Microelectronics Corporation | Sensing method and circuit of fingerprint sensor |
| WO2017071130A1 (en) * | 2015-10-28 | 2017-05-04 | 深圳市汇顶科技股份有限公司 | Pixel module and fingerprint recognition system |
| CN108267648A (en) * | 2016-12-30 | 2018-07-10 | 致茂电子(苏州)有限公司 | Detection device with antistatic protection function |
| CN109873397A (en) * | 2019-01-31 | 2019-06-11 | 上海思立微电子科技有限公司 | A kind of method, apparatus and system of chip electrostatic protection |
| CN112579201A (en) * | 2020-12-16 | 2021-03-30 | 惠州Tcl移动通信有限公司 | Fingerprint induction starting method and device, storage medium and mobile terminal |
| CN115347526A (en) * | 2022-10-17 | 2022-11-15 | 荣耀终端有限公司 | Side fingerprint protection circuit, control method and electronic equipment |
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| CN105608413B (en) * | 2014-11-14 | 2020-04-28 | 深圳市汇顶科技股份有限公司 | Fingerprint sensor latch recovery mechanism based on status monitoring and handshaking |
| CN105608413A (en) * | 2014-11-14 | 2016-05-25 | 深圳市汇顶科技股份有限公司 | Latch recovery mechanism of fingerprint sensor based on state monitoring and handshake |
| CN109359571B (en) * | 2014-11-14 | 2022-08-12 | 深圳市汇顶科技股份有限公司 | Fingerprint sensor latch recovery mechanism based on status monitoring and handshaking |
| CN108985284A (en) * | 2014-11-14 | 2018-12-11 | 深圳市汇顶科技股份有限公司 | Latch Restoration Mechanism based on Stateful Inspection and the fingerprint sensor shaken hands |
| CN108985283A (en) * | 2014-11-14 | 2018-12-11 | 深圳市汇顶科技股份有限公司 | Latch Restoration Mechanism based on Stateful Inspection and the fingerprint sensor shaken hands |
| CN109359571A (en) * | 2014-11-14 | 2019-02-19 | 深圳市汇顶科技股份有限公司 | Latch Restoration Mechanism based on Stateful Inspection and the fingerprint sensor shaken hands |
| TWI559232B (en) * | 2014-12-15 | 2016-11-21 | 義隆電子股份有限公司 | Sensing method and circuit of fingerprint sensor |
| US9613247B2 (en) | 2014-12-15 | 2017-04-04 | Elan Microelectronics Corporation | Sensing method and circuit of fingerprint sensor |
| WO2017071130A1 (en) * | 2015-10-28 | 2017-05-04 | 深圳市汇顶科技股份有限公司 | Pixel module and fingerprint recognition system |
| US10354119B2 (en) | 2015-10-28 | 2019-07-16 | Shenzhen GOODIX Technology Co., Ltd. | Pixel module and fingerprint identification system |
| CN108267648A (en) * | 2016-12-30 | 2018-07-10 | 致茂电子(苏州)有限公司 | Detection device with antistatic protection function |
| CN109873397A (en) * | 2019-01-31 | 2019-06-11 | 上海思立微电子科技有限公司 | A kind of method, apparatus and system of chip electrostatic protection |
| CN112579201A (en) * | 2020-12-16 | 2021-03-30 | 惠州Tcl移动通信有限公司 | Fingerprint induction starting method and device, storage medium and mobile terminal |
| CN115347526A (en) * | 2022-10-17 | 2022-11-15 | 荣耀终端有限公司 | Side fingerprint protection circuit, control method and electronic equipment |
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