A sensitive amplifier, a control method and Nand Flash

Abstract

The present invention discloses a sensitive amplifier, a control method and Nand Flash. The sensitive amplifier includes: a latch module, a control module and a detection module; the detection output end of the detection module is connected to the control input end of the control module, and the control output end of the control module is connected to the latch control end of the latch module; the detection module is used to detect an input voltage signal, and output a control adjustment signal to the control input end based on the input voltage signal and the control voltage signal of the detection control end; the control module is used to adjust the second pre-charge voltage of the control output end based on the control adjustment signal and the first pre-charge voltage of the control input end to obtain a latch control signal; the latch module is used to latch the result of detecting the input voltage signal based on the latch control signal. By using this sensitive amplifier, the detection depth of the negative threshold voltage can be increased, and the interference caused by the shallow erase depth can be reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of memory technology, and in particular to a sense amplifier, a control method and NandFlash. Background Art

[0002] With the development of science and technology, NAND Flash memory has been widely used. Nand Flash is a kind of Flash memory, which belongs to non-volatile memory device. It uses non-linear macro cell mode inside, has the advantages of large capacity and fast rewrite speed, and is suitable for storing large amounts of data.

[0003] In Nand Flash, the erasing and programming operations of Nand Flash are both achieved by applying corresponding voltages to the erase block or programming page to change the threshold voltage of the floating gate of the storage cell. Among them, the erasing operation of NAND Flash requires the threshold voltage of the storage cell to be erased to below 0V. When detecting the threshold voltage, the traditional erase detection scheme has a small amplitude of the detected negative threshold voltage, so it is difficult to erase the threshold voltage of the storage cell to a very negative value. Therefore, the maximum value of the threshold voltage of the erased storage cell is usually around 0V. As the programming and erasing cycles increase, the threshold voltage of the erased storage cell will drift to the voltage corresponding to the programming area, thereby causing programming interference. Summary of the invention

[0004] The embodiments of the present invention provide a sense amplifier, a control method and a Nand Flash to improve the depth of the sense amplifier in detecting a negative threshold voltage.

[0005] In a first aspect, an embodiment of the present invention provides a sensitive amplifier, comprising: a latch module, a control module and a detection module;

[0006] The detection output end of the detection module is connected to the control input end of the control module, and the control output end of the control module is connected to the latch control end of the latch module;

[0007] The detection module is used to detect an input voltage signal, and output a control adjustment signal to the control input terminal based on the input voltage signal and a control voltage signal of the detection control terminal;

[0008] The control module is used to adjust the second pre-charge voltage of the control output terminal based on the control adjustment signal and the first pre-charge voltage of the control input terminal to obtain a latch control signal;

[0009] The latch module is used to latch the result of detecting the input voltage signal based on the latch control signal.

[0010] Optionally, the control module includes a first switch unit, a second switch unit and a coupling unit;

[0011] The first end of the first switch unit is respectively connected to the first end of the second switch unit, the first end of the coupling unit and the detection output end, and the second end of the second switch unit is respectively connected to the second end of the coupling unit and the latch control end of the latch unit;

[0012] The first switch unit and the second switch unit are used to supply a first pre-charge voltage to the control input terminal and a second pre-charge voltage to the control output terminal;

[0013] The coupling unit is used to adjust the second pre-charge voltage based on the first pre-charge voltage and the control adjustment signal to obtain a latch control signal.

[0014] Optionally, the control module further includes: a third switch unit, a first end of the third switch unit is connected to the second end of the coupling unit, and is used to supply a second pre-charge voltage to the control output end.

[0015] Optionally, the coupling unit includes a capacitor.

[0016] Optionally, the first switch unit, the second switch unit and the third switch unit include field effect transistors.

[0017] In a second aspect, an embodiment of the present invention further provides a control method for controlling the sense amplifier described in the embodiment of the present invention, the method comprising:

[0018] Respectively charging the voltages of the control input terminal and the control output terminal of the control module to a first pre-charge voltage and a second pre-charge voltage;

[0019] Receiving an input voltage signal and disconnecting the control module power supply;

[0020] The control detection module detects the input voltage signal to obtain a control adjustment signal;

[0021] A set signal is input to the latch module to control the latch module to latch the result of detecting the input voltage signal based on the set signal and a latch control signal, wherein the latch control signal is determined by the control module adjusting the second pre-charge voltage based on the control adjustment signal and the first pre-charge voltage.

[0022] Optionally, before respectively charging the voltages of the control input terminal and the control output terminal of the control module to the first pre-charge voltage and the second pre-charge voltage, the method further includes:

[0023] The detection input end of the detection module, the control input end of the control module and the control output end of the control module are discharged respectively.

[0024] Optionally, after respectively charging the voltages of the control input terminal and the control output terminal of the control module to the first pre-charge voltage and the second pre-charge voltage, the method further includes:

[0025] Reset latch module.

[0026] In a third aspect, an embodiment of the present invention further provides a Nand Flash, comprising: the sensitive amplifier provided in the embodiment of the present invention and / or a control unit, and the control unit executes the control method provided in the embodiment of the present invention.

[0027] The embodiment of the present invention provides a sensitive amplifier, a control method and Nand Flash. By using the above technical solution, the input voltage signal can be detected by the detection module, and the control adjustment signal can be transmitted to the control module based on the input voltage signal and the control voltage signal of the detection control end. After receiving the control adjustment signal, the control module adjusts the second pre-charge voltage of the control output end based on the control adjustment signal and the first pre-charge voltage of the control input end to obtain a latch control signal. The latch module latches the result of detecting the input voltage signal based on the latch control signal. Since the latch control signal of the control latch module is controlled and adjusted based on the first pre-charge voltage, the second pre-charge voltage and the control adjustment signal, the sensitive amplifier provided in this embodiment increases the detection depth of the negative threshold voltage. When the sensitive amplifier is applied to Nand Flash threshold detection, the interference caused by the shallow erase depth can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of a sensitive amplifier provided by an embodiment of the present invention;

[0029] Figure 2 A connection diagram of a sensitive amplifier provided by an embodiment of the present invention;

[0030] Figure 3 A connection diagram of another sensitive amplifier provided by an embodiment of the present invention;

[0031] Figure 4 A connection diagram of another sensitive amplifier provided by an embodiment of the present invention;

[0032] Figure 5 In the implementation of the present invention Figure 4 The voltage timing diagram of the sense amplifier detecting the negative threshold is shown;

[0033] Figure 6 A schematic diagram of a Nand Flash array provided by an embodiment of the present invention;

[0034] Figure 7 In the embodiment of the present invention Figure 4 The voltage timing diagram of the sense amplifier detecting the negative threshold is shown;

[0035] Figure 8 A flow chart of a control method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0037] Embodiment 1

[0038] Figure 1 The present invention provides a schematic diagram of the structure of a sensitive amplifier provided in an embodiment of the present invention. The sensitive amplifier can be applicable to the case of detecting an input voltage signal, wherein the input voltage signal can be a signal inputted externally to the sensitive amplifier. Specifically, the sensitive amplifier can be applicable to the case of detecting the threshold voltage of a storage cell of a NAND Flash. The sensitive amplifier can be integrated on a Nand Flash to detect the threshold voltage of a storage cell.

[0039] like Figure 1 As shown, an embodiment of the present invention provides a sensitive amplifier, comprising:

[0040] Latch module 11, control module 12 and detection module 13;

[0041] The detection output terminal of the detection module 13 is connected to the control input terminal of the control module 12, and the control output terminal of the control module 12 is connected to the latch control terminal of the latch module 11;

[0042] The detection module 13 is used to detect the input voltage signal and output a control adjustment signal to the control input terminal based on the input voltage signal and the control voltage signal of the detection control terminal;

[0043] A control module 12, configured to adjust a second pre-charge voltage at a control output terminal based on a control adjustment signal and a first pre-charge voltage at a control input terminal, to obtain a latch control signal;

[0044] The latch module 11 is used to latch the result of detecting the input voltage signal based on a latch control signal.

[0045] The sensitive amplifier in this embodiment includes a latch module 11, a control module 12 and a detection module 13. The working principle of the sensitive amplifier can be that when performing signal detection, the detection module 13 of the sensitive amplifier receives an input voltage signal, and then outputs a control adjustment signal to the control input terminal based on the input voltage signal and the control voltage signal of the detection control terminal; after receiving the control adjustment signal, the control module 12 adjusts the second pre-charge voltage of the control output terminal in combination with the first pre-charge voltage of the control input terminal to obtain a latch control signal, and transmits the latch control signal to the latch module 11; the latch module 11 latches the result of detecting the input signal based on the latch control signal.

[0046] In this embodiment, the latch module 11 can be understood as a module for latching the detection result of the input voltage signal. The control module 12 can be understood as a module for controlling the state of the latch module 11. The detection module 13 can be understood as a module for detecting the input voltage signal. The detection module 13 can output a control adjustment signal to the control module 12 based on the input voltage signal to adjust the control state of the latch module 11 by the control module 12.

[0047] Among them, the detection module 13 may include a detection output terminal and a detection input terminal, the detection input terminal may be used to monitor the input voltage signal, and the detection output terminal may output a control adjustment signal to the control input terminal based on the input voltage signal and the control voltage signal. That is, the detection module 13 may determine the corresponding control adjustment signal based on the supply condition of the control voltage signal and the size of the input voltage signal, and output the control adjustment signal to the control module 12, so that the control module 12 adjusts the latch control signal output to the latch module 11 based on the control adjustment signal. The latch module 11 can latch the result of the corresponding input voltage signal based on the latch control signal.

[0048] The input voltage signal may be a signal detected by a sense amplifier, such as a voltage signal on a bit line in a storage array of a Nand Flash. The control voltage signal may be a signal for the control detection module 13 to control and adjust the signal output.

[0049] When the detection module 13 receives the control voltage signal, it can determine the control adjustment signal output by the detection output terminal based on the input voltage signal detected by the detection input terminal and the control voltage signal. The control adjustment signal can be understood as a signal for adjusting the control output terminal voltage in the control module 12.

[0050] The first pre-charge voltage can be understood as the voltage signal obtained by pre-charging the control input end of the control module 12 before the input voltage signal is detected. The second pre-charge voltage can be understood as the voltage signal obtained by pre-charging the control output end of the control module 12 before the input voltage signal is detected. Wherein, the numerical values ​​of the first pre-charge voltage and the second pre-charge voltage are not limited, and those skilled in the art can determine it according to the threshold value of the input voltage signal that the sensitive amplifier wants to detect. The latch control signal can be understood as the voltage signal obtained after adjusting the second pre-charge voltage based on the control adjustment signal and the first pre-charge voltage.

[0051] It is understandable that the control module 12 may have a voltage regulation function, such as adjusting the second pre-charge voltage of the control output terminal based on the first pre-charge voltage obtained by pre-charging the control input terminal and the control adjustment signal transmitted to the control input terminal when detecting the input voltage signal, so as to obtain a latch control signal. The value of the latch control signal may be determined based on the first pre-charge voltage, the second pre-charge voltage and the value of the control adjustment signal.

[0052] After the latch module 11 receives the latch control signal, it can latch the detection result of the input voltage signal based on the latch control signal. The detection result can be identified by 1 and 0. The latch module 11 can flip the latch result based on the set flip point. When the voltage value of the control adjustment signal reaches the set flip point, the latch module 11 can flip the latch result. The voltage value of the control adjustment signal can be controlled by the voltage value of the input voltage signal. Therefore, the latch module 11 can latch the result of detecting the input voltage signal.

[0053] A sensitive amplifier provided by an embodiment of the present invention can detect an input voltage signal through a detection module using the above method, and transmit a control adjustment signal to a control module based on the input voltage signal and the control voltage signal of the detection control terminal. After receiving the control adjustment signal, the control module adjusts the second pre-charge voltage of the control output terminal based on the control adjustment signal and the first pre-charge voltage of the control input terminal to obtain a latch control signal. The latch module latches the result of detecting the input voltage signal based on the latch control signal. Since the latch control signal of the control latch module is controlled and adjusted based on the first pre-charge voltage, the second pre-charge voltage and the control adjustment signal, the sensitive amplifier provided by this embodiment increases the detection depth of the negative threshold voltage. When the sensitive amplifier is applied to Nand Flash threshold detection, the interference caused by the shallow erase depth can be reduced.

[0054] In this embodiment, the control module 12 in the sense amplifier may be optimized, including the first switch unit, the second switch unit and the coupling unit;

[0055] The first end of the first switch unit is respectively connected to the first end of the second switch unit, the first end of the coupling unit and the detection output end, and the second end of the second switch unit is respectively connected to the second end of the coupling unit and the latch control end of the latch unit;

[0056] The first switch unit and the second switch unit are used to supply a first pre-charge voltage to the control input terminal and a second pre-charge voltage to the control output terminal;

[0057] The coupling unit is used to adjust the second pre-charge voltage based on the first pre-charge voltage and the control adjustment signal to obtain a latch control signal.

[0058] The control module 12 in the sense amplifier can be optimized to include a first switch unit, a second switch unit and a coupling unit. Among them, the first switch unit can be understood as a unit for controlling the voltage of the control input terminal, and the first switch unit can be used to provide a first pre-charge voltage for the control input terminal of the control module 12. The second switch unit can be understood as a unit for controlling the voltage of the control output terminal, and the second switch unit can be used to provide a second pre-charge voltage for the control output terminal of the control module 12. The coupling unit can be understood as a unit for voltage adjustment in the control module 12. The coupling unit can adjust the second pre-charge voltage based on the first pre-charge voltage and the control adjustment signal to obtain a latch control signal.

[0059] The specific components included in the first switch unit and the second switch unit are not limited here, and those skilled in the art can set them according to actual conditions, as long as the first switch unit and the second switch unit can control the voltage of the control input terminal and the control output terminal respectively. For example, the first switch unit and the second switch unit may include at least one field effect transistor, and may also include a resistor and capacitor element. The coupling unit may include a device capable of coupling, such as at least one capacitor, and may also include a resistor and capacitor element.

[0060] For example, Figure 2 FIG. 1 is a connection diagram of a sensitive amplifier provided by an embodiment of the present invention. Figure 2 As shown, the control module 12 includes a first switch unit S1, a second switch unit S3 and a coupling unit C1. In addition, the control module 12 may also include a discharge unit M4, which may include a field effect transistor. The discharge unit M4 may discharge the control input terminal SEN, the control output terminal SBUS and the input voltage signal BL of the control module 12.

[0061] The latch module 11 may include a first inverter I1, a second inverter I2, a set switch tube M6, a reset switch tube M7 and a control switch tube M5. The first inverter I1 and the second inverter I2 form a latch, which is used to latch the result of the sense amplifier detecting sense. The set switch tube M6, the reset switch tube M7 and the control switch tube M5 can be used to control the reset and setting of the latch.

[0062] The latch module 11 controls the conduction state of the control switch tube M5 based on the latch control signal, and latches the detection result of the input voltage signal in combination with the set signal of the control end of the set switch tube M6 and the reset signal of the control end of the reset switch tube M7.

[0063] The detection module 13 may include a high-voltage isolation tube M3 and a clamp tube M2, wherein the high-voltage isolation tube M3 may be in a normally-on state for high-voltage isolation. The clamp tube M2 may determine a control adjustment signal based on the detection control signal BLC and the input voltage signal BL. That is, when the difference between the detection control signal BLC and the input voltage signal BL is greater than the conduction voltage of the clamp tube M2, the input voltage signal is used as the control adjustment signal. When the difference between the detection control signal BLC and the input voltage signal BL is not greater than the conduction voltage of the clamp tube M2, the connection between the detection module 13 and the control module 12 may be disconnected.

[0064] Furthermore, the control module 12 further includes: a third switch unit, a first end of the third switch unit is connected to the second end of the coupling unit, and is used to supply a second pre-charge voltage to the control output end.

[0065] In addition, this embodiment further provides an implementation of the control module 12 . In this implementation, the control module 12 is added with a third switch unit on the basis of the above implementation to charge the control module 12 .

[0066] Specifically, the first end of the third switch unit is connected to the second end of the coupling unit C1 to directly charge the second end of the coupling unit C1. Figure 2 In the connection mode shown in , when the second end of the coupling unit C1 is charged, the first switch unit S1 and the second switch unit S3 need to work together, such as closing. Exemplarily, the first switch unit S1 and the second switch unit S3 can be closed to charge the control output terminal SBUS to the second preset voltage, and then the second switch tube S3 can be opened to charge the control input terminal SEN to the first preset voltage. Figure 2 The power source V1 in the embodiment can provide voltages of at least two amplitudes.

[0067] Furthermore, the coupling unit C1 includes a capacitor.

[0068] Furthermore, the first switch unit S1 , the second switch unit S3 and the third switch unit include field effect transistors.

[0069] Figure 3 A connection diagram of another sensitive amplifier provided by an embodiment of the present invention is shown in FIG. Figure 3 As shown, the control module 12 in the sense amplifier optimally includes a third switch unit S2.

[0070] In order to detect a more negative threshold voltage, the sense amplifier proposed in this embodiment uses a coupling capacitor to detect voltage changes, which can avoid readout errors caused by a final voltage at the control input terminal being too large.

[0071] Figure 4 A connection diagram of yet another sensitive amplifier provided in an embodiment of the present invention. Figure 5 In the implementation of the present invention Figure 4 Figure 2 shows the voltage timing diagram of the sense amplifier detecting the negative threshold. Figure 4 The sense amplifier provided in the embodiment is a connection mode of the sense amplifier when the coupling unit C1 and the corresponding first switch unit S1, second switch unit S3 and third switch unit S2 are not included.

[0072] See also Figure 4 and Figure 5 The charging tube M1 can charge the control signal SEN0 that controls the switch tube M5.

[0073] Take the example of using a sensitive amplifier to detect the threshold voltage of a storage cell in Nand Flash. Figure 6 The schematic diagram of the array of Nand Flash provided by the embodiment of the present invention. Figure 6 As shown, each bit line (BL) is connected to a sense amplifier (SA); the drain select line (DSL), word line (WL) <31:0>, and source select line (SSL) are connected in series to form a string, the drain end of BL and the DSL of the string is connected, and the SSL of the string is connected to the common source line (CSL), which is shared by all strings in the entire array.

[0074] See also Figure 4-6 , the working principle of the sense amplifier is as follows:

[0075] After the detection sense starts, set the CSL in the Nand Flash memory array to VDD, the SSL to VDD, bias the selected WL to 0V, keep the control signal BLS of the high-voltage isolation transistor M3 high, and the high-voltage isolation transistor M3 is always on. At the beginning, set the discharge control signal DIS of the discharge unit M4 to high, and set the detection control signal BLC of the clamping transistor M2 to high, so that the control signal SEN0 of the control switch transistor M5 and the input voltage signal BL are discharged to 0, and then cut off the supply of the detection control signal BLC of the clamping transistor M2.

[0076] At time t1, turn on the charging control signal PCH of the charging transistor M1, charge the control signal SEN0 to VDD, and after completion, turn off the charging control signal PCH to make the voltage at the control signal SEN0 float.

[0077] At time t2, apply a high-level pulse to the reset signal RST of the reset switch transistor M7 to set the output Q of the latch to 0; set the discharge control signal DIS low to turn off the discharge unit M4.

[0078] At time t3, turn on DSL in the Nand Flash memory array. Assume that the threshold of the selected memory cell is -Vt. Since WL is 0V, BL will be charged to the voltage of Vt (the charging direction is from CSL through SSL through WL and then through DSL to BL), as shown by the rising dotted line of BL at time t3. The more negative the cell threshold, the higher the BL voltage. If the cell threshold is greater than 0, the entire string is not conducting and BL remains at 0V. Figure 5 As shown by the dotted line of BL rising at time t3. The more negative the cell threshold, the higher the BL voltage. If the cell threshold is greater than 0, the entire string is not conducting and BL remains at 0V.

[0079] At time t4, turn on the clamping transistor M2 and set the voltage of the detection control signal BLC equal to Vsense + Vtn, where Vtn is the threshold of the clamping transistor M2 (NMOS transistor). Vsense can be considered as the voltage threshold that the sense amplifier can detect. If the voltage Vbl of BL is less than Vsense, the clamping transistor M2 conducts and the control signal SEN0 drops to Vsense (the capacitance of the control signal SEN0 is much smaller than the capacitance of the input voltage signal BL, and charge sharing occurs). If the voltage Vbl is greater than Vsense, the clamping transistor M2 is cut off (VGS < Vtn) and the control signal SEN0 remains at VDD.

[0080] At time t5, the set signal SET of the set switch tube M6 starts a high level pulse. If the control signal SEN0 is greater than the flip voltage of the latch at this time, the output Q of the latch is set to 1. If the control signal SEN0 is less than the flip voltage of the latch, the output Q of the latch remains at 0. Generally, the flip voltage of the latch is less than 1V, so the voltage of Vsense cannot be too high, otherwise even if the clamp tube M2 is turned on, the control signal SEN0 drops to Vsense, which will cause the latch to flip.

[0081] From the above analysis, it can be seen that Figure 4 The scheme for detecting negative thresholds shown cannot detect too negative thresholds, because to detect a more negative threshold, Vsense needs to be set larger, so the detectable Vbl also becomes larger. Since Vbl is too large, the final voltage of the control signal SEN0 for erasing the memory cell is too large, which will cause the latch to flip by mistake, and it will be impossible to distinguish between 1 (for erasing the memory cell Erase cell) and 0 (for programming the memory cell Pgmcell), resulting in a read error.

[0082] Therefore, this embodiment Figure 3 The provided sensitive amplifier detects the voltage change of the control input terminal SEN through the coupling unit C1 and couples it to the control output terminal SBUS. The control output terminal is connected to the control switch tube M5 for controlling the latch flip. The first switch unit S1 is a switch for charging the control input terminal SEN to the power supply V1. The third switch unit S2 is a switch for charging the control output terminal SBUS to the power supply V2. The second switch unit S3 is a switch connecting the control input terminal SEN and the control output terminal SBUS.

[0083] Figure 7 In the embodiment of the present invention Figure 4 The voltage timing diagram of the sense amplifier detecting the negative threshold is shown in FIG. Figure 3 , Figure 6 and Figure 7 , WL, DSL, SSL, and CSL bias and Figure 4 The bias in the high-voltage isolation tube M3 is always on. Before t1, the second switch unit S3 is turned on, the detection control signal BLC, the control signal BLS of the high-voltage isolation tube M3, and the discharge control signal DIS of the discharge unit M4 are set high, BL, the control input terminal SEN and the control output terminal SBUS are discharged to VSS, and then the second switch unit S3 and the detection control signal BLC are turned on at time t1, the control input terminal SEN is charged to V1, and the control output terminal SBUS is charged to V2. At time t2, a pulse of the reset signal RST is turned on, the output Q of the latch is set to 0, and the discharge unit M4 is turned off.

[0084] At time t3, DSL is turned on, and BL rises with the threshold voltage of the storage unit cell; the first switch unit S1 and the second switch unit S3 are turned off, and the control output terminal SBUS and the control input terminal SEN are left floating.

[0085] At time t4, the detection control signal BLC is turned on, and the voltage of the detection control signal BLC is Vsense+Vtn. If the BL voltage is greater than Vsense, the clamp tube M2 is turned off, the control input terminal SEN voltage is maintained at V1, and the control output terminal SBUS is also maintained at V2; if the BL voltage Vbl is less than Vsense, the control input terminal SEN is pulled to Vbl. Considering the worst case, Vbl is equal to Vsense, the clamp tube M2 is just turned on, and the control input terminal SEN is pulled to Vsense. At this time, due to the influence of the coupling capacitor C1, the voltage of the control output terminal SBUS is:

[0086] V SBUS =V2-(V1-Vsense)×C1 / C SBUS ;

[0087] Among them, C SBUS is the total capacitance of the control output terminal SBUS.

[0088] At time t5, the reset signal of the setting switch tube M6 is set. If the voltage of the control output terminal SBUS is less than the trigger point, the output Q of the latch is 0. If the voltage of the control output terminal SBUS is greater than the trigger point, the output Q of the latch is 1. Since the final voltage of the control output terminal SBUS is V2-(V1-Vsense)×C1 / Csbus, when Vsense is set larger, V1 and V2 as well as C1 and Csbus can be adjusted. SBUS The voltage of the control output terminal SBUS is adjusted by the ratio of , so that it is less than the flip voltage. The sense amplifier provided in this embodiment can increase the size of the negative threshold to be detected without affecting the readout accuracy.

[0089] The sensitive amplifier provided in this embodiment uses a coupling capacitor to couple the voltage jump of the control input terminal to the control output terminal, thereby solving the problem that the related art cannot detect excessive negative voltage.

[0090] The embodiment of the present invention further provides a control method for controlling the sensitive amplifier provided in the embodiment. Figure 8A flow chart of a control method provided in an embodiment of the present invention is provided. The method can be applied to a case where a sense amplifier is controlled to detect an input voltage signal, wherein the input voltage signal can be a signal inputted externally to the sense amplifier. Specifically, the method can be applied to a case where a sense amplifier is controlled to detect a threshold voltage of a storage unit of a NAND Flash. The method can be executed by a control unit, and the control unit can be integrated on the NAND Flash.

[0091] like Figure 8 As shown, a control method provided by an embodiment of the present invention includes the following steps:

[0092] S101 , respectively charging the voltages of a control input terminal and a control output terminal of a control module to a first pre-charge voltage and a second pre-charge voltage.

[0093] The control method in this embodiment is used to control the sense amplifier in this embodiment. The control method in this embodiment has the corresponding functional modules and beneficial effects of the sense amplifier, which will not be described in detail here.

[0094] The control method of this embodiment can first control the control input terminal and the control output terminal of the control module of the sensitive amplifier to be precharged to the first precharge voltage and the second precharge voltage when controlling the sensitive amplifier to perform threshold detection, so that when detecting the input voltage signal, the second precharge voltage can be adjusted based on the input voltage signal and the first precharge voltage to obtain a control adjustment signal, thereby controlling the latch module to latch the detection result of the input voltage signal.

[0095] In addition, after charging the control input terminal and the control output terminal, the latch module can be controlled to perform a reset operation based on the second pre-charge voltage of the control output terminal.

[0096] The charging method of the control input terminal and the control output terminal of the control module is not limited here, for example, the on-off of at least one field effect transistor may be controlled.

[0097] See also Figure 3 In this step, the first switch unit S1 and the third switch unit S2 can be closed to charge the control input terminal and the control input terminal of the control module to the first pre-charge voltage and the second pre-charge voltage.

[0098] S102, receiving an input voltage signal and disconnecting the power supply of the control module.

[0099] After the control input terminal and the control output terminal are charged to the first pre-charge voltage and the second pre-charge voltage respectively, in this step, the detection module may receive the input voltage signal and then detect the input voltage signal.

[0100] In addition, this step can also disconnect the power supply of the control module, such as disconnecting the field effect transistors corresponding to the control input and control output. Figure 3 , disconnecting the power supply of the control module can be achieved by disconnecting the first switch unit S1, the second switch unit S3 and the third switch unit S2.

[0101] S103: The control detection module detects the input voltage signal to obtain a control adjustment signal.

[0102] After disconnecting the power supply of the control module, this step can control the detection module to detect the input voltage signal, such as by outputting a control voltage signal to the detection control terminal of the detection module to control the detection module to detect the input voltage signal.

[0103] After the control detection module detects the input voltage signal, a detection result output by the detection output terminal of the detection module, that is, a control adjustment signal, can be obtained.

[0104] See also Figure 3 If the difference between the control voltage signal and the input voltage signal is greater than the conduction voltage of the clamp tube M2, the input voltage signal can be used as the control adjustment signal; otherwise, the connection between the detection module and the control module can be disconnected so that the voltage at the control input end of the control module is maintained at the first pre-charge voltage and the voltage at the control output end is maintained at the second pre-charge voltage.

[0105] S104, inputting a set signal to the latch module to control the latch module to latch the result of detecting the input voltage signal based on the set signal and a latch control signal, wherein the latch control signal is determined by the control module adjusting the second pre-charge voltage based on the control adjustment signal and the first pre-charge voltage.

[0106] After obtaining the control adjustment signal, this step can input a set signal to the latch module, so that the latch module can latch the detection result of the input voltage signal based on the latch control signal. The latch control signal is affected by the control adjustment signal.

[0107] See also Figure 3 After the control detection module detects the input voltage signal, this step can input a set signal SET to the set switch tube M6, so that the latch module can determine whether to turn on the control switch tube M5 based on the latch control signal output from the control output end to adjust the latch result of the latch module.

[0108] A control method provided by an embodiment of the present invention first charges the voltage of the control input terminal and the control output terminal of the control module to a first pre-charge voltage and a second pre-charge voltage respectively; then receives an input voltage signal and disconnects the power supply of the control module; then controls the detection module to detect the input voltage signal to obtain a control adjustment signal; finally inputs a set signal to a latch module to control the latch module to latch the result of detecting the input voltage signal based on the set signal and the latch control signal, and the latch control signal is determined by the control module adjusting the second pre-charge voltage based on the control adjustment signal and the first pre-charge voltage. Using the above method, the detection depth of the negative threshold voltage of the sensitive amplifier can be increased. When the sensitive amplifier is applied to Nand Flash threshold detection, the interference caused by the shallow erase depth can be reduced.

[0109] Furthermore, before respectively charging the voltages of the control input terminal and the control output terminal of the control module to the first pre-charge voltage and the second pre-charge voltage, the method further includes:

[0110] The detection input end of the detection module, the control input end of the control module and the control output end of the control module are discharged respectively.

[0111] Before charging the control input terminal and the control output terminal, the present embodiment may first discharge the detection input terminal, the control input terminal and the control output terminal of the detection module to avoid the influence of the undischarged sensitive amplifier on the detection result.

[0112] When performing a discharge operation, the corresponding port may be grounded, and the specific grounding means may not be limited.

[0113] See also Figure 3 When discharging, the second switch unit S3 can be closed to output a detection control signal BLC to the detection module M2 and a control signal BLS to the high-voltage isolation tube M3, so that the control input terminal, the control output terminal and the detection input terminal are grounded to achieve discharge.

[0114] Furthermore, after respectively charging the voltages of the control input terminal and the control output terminal of the control module to the first pre-charge voltage and the second pre-charge voltage, the method further includes:

[0115] Reset latch module.

[0116] After the charging operation is completed, that is, the control input terminal and the control output terminal are charged to the first pre-charge voltage and the second pre-charge voltage respectively, the latch module can be reset in this embodiment to ensure the accuracy of the latch result of the input voltage signal. The specific means of resetting may not be limited, for example, it can be achieved by inputting a reset signal RST to the control terminal of the reset switch tube M7.

[0117] An embodiment of the present invention further provides a Nand Flash, which includes: the sense amplifier provided in the embodiment of the present invention and / or includes a control unit, and the control unit executes the control method provided in any embodiment of the present invention.

[0118] The connection method between the sense amplifier and the memory cell array can be found in Figure 6 The control unit can be connected to the sense amplifier and the memory cell array respectively to output control signals to the sense amplifier and the memory array respectively, thereby realizing control over the sense amplifier.

[0119] The Nand Flash provided in this embodiment includes the sensitive amplifier in this embodiment and / or includes a control unit, and the control unit is used to execute the control method provided in this embodiment. The implementation principle and technical effect of the Nand Flash provided in this embodiment when performing threshold voltage detection are similar to those of the control method and the sensitive amplifier provided in this embodiment, and are not repeated here.

[0120] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A sensitive amplifier, characterized in that: include: Latch module, control module and detection module; The detection output end of the detection module is connected to the control input end of the control module, and the control output end of the control module is connected to the latch control end of the latch module; The detection module is used to detect an input voltage signal, and output a control adjustment signal to the control input terminal based on the input voltage signal and a control voltage signal of the detection control terminal; The control module is used to adjust the second pre-charge voltage of the control output terminal based on the control adjustment signal and the first pre-charge voltage of the control input terminal to obtain a latch control signal; The latch module is used to latch the result of detecting the input voltage signal based on the latch control signal; The control module comprises a first switch unit, a second switch unit and a coupling unit; The first end of the first switch unit is respectively connected to the first end of the second switch unit, the first end of the coupling unit and the detection output end, and the second end of the second switch unit is respectively connected to the second end of the coupling unit and the latch control end of the latch module; The first switch unit and the second switch unit are used to supply a first pre-charge voltage to the control input end and to supply a second pre-charge voltage to the control output end.

2. The sense amplifier according to claim 1, characterized in that: The coupling unit is used to adjust the second pre-charge voltage based on the first pre-charge voltage and the control adjustment signal to obtain a latch control signal.

3. The sense amplifier according to claim 2, characterized in that: The control module further includes: a third switch unit, a first end of which is connected to the second end of the coupling unit and is used to supply a second pre-charge voltage to the control output end.

4. The sense amplifier according to claim 2, characterized in that: The coupling unit includes a capacitor.

5. The sensitive amplifier according to claim 3, characterized in that: The first switch unit, the second switch unit, and the third switch unit include field effect transistors.

6. A control method, characterized in that: Used to control the sensitive amplifier according to any one of claims 1 to 5, the method comprising: Respectively charging the voltages of the control input terminal and the control output terminal of the control module to a first pre-charge voltage and a second pre-charge voltage; Receiving an input voltage signal and disconnecting the control module power supply; The control detection module detects the input voltage signal to obtain a control adjustment signal; A set signal is input to the latch module to control the latch module to latch the result of detecting the input voltage signal based on the set signal and a latch control signal, wherein the latch control signal is determined by the control module adjusting the second pre-charge voltage based on the control adjustment signal and the first pre-charge voltage.

7. The method according to claim 6, characterized in that Before respectively charging the voltages of the control input terminal and the control output terminal of the control module to the first pre-charge voltage and the second pre-charge voltage, the method further includes: The detection input end of the detection module, the control input end of the control module and the control output end of the control module are discharged respectively.

8. The method according to claim 6, characterized in that After respectively charging the voltages of the control input terminal and the control output terminal of the control module to the first pre-charge voltage and the second pre-charge voltage, the method further includes: Reset latch module.

9. A Nand Flash, characterized in that: It comprises a sensitive amplifier as described in any one of claims 1-5; and / or a control unit, wherein the control unit executes the control method as described in any one of claims 6-8.

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