Leakage detection circuit, flash memory leakage detection device and leakage detection method

Abstract

The present invention discloses a leakage detection circuit, a flash memory leakage detection device and a leakage detection method. The leakage detection circuit includes a detection input terminal, a detection output terminal, a first capacitor, a second capacitor, a first switch unit, a second switch unit, a power input terminal, a voltage divider unit and a comparison unit; the first terminal of the first capacitor is electrically connected to the detection input terminal, and the second terminal is electrically connected to the first input terminal of the comparison unit; the first terminal of the second capacitor is electrically connected to the first input terminal of the comparison unit, and the second terminal is grounded; the first terminal of the first switch unit is electrically connected to the power input terminal, and the second terminal is electrically connected to the first terminal of the first capacitor; the first terminal of the second switch unit is electrically connected to the first output terminal of the voltage divider unit, and the second terminal is electrically connected to the second terminal of the first capacitor; the second output terminal of the voltage divider unit is electrically connected to the second input terminal of the comparison unit; the output terminal of the comparison unit is electrically connected to the detection output terminal. Convenient and efficient detection of leakage current of the circuit to be detected can be realized.

Description

Technical Field

[0001] The embodiments of the present invention relate to leakage detection technology, and more particularly to a leakage detection circuit, a flash memory leakage detection device and a leakage detection method. Background Art

[0002] With the rapid development of semiconductor and other technologies, leakage current detection plays a very important role in some precision devices, such as flash memory. Bad blocks in flash memory can be marked in time to prevent data from being written into bad blocks.

[0003] As the size of flash memory chips is getting smaller and smaller, the spacing between word lines and between word lines and substrates is also smaller. The existing technology cannot accurately detect leakage between word lines and sub-lines and between word lines and substrates. Summary of the invention

[0004] The present invention provides a leakage detection circuit, a flash memory leakage detection device and a leakage detection method, so as to realize convenient and efficient detection of leakage current of a circuit to be detected.

[0005] In a first aspect, an embodiment of the present invention provides a leakage detection circuit, the leakage detection circuit comprising: a detection input terminal, a detection output terminal, a first capacitor, a second capacitor, a first switch unit, a second switch unit, a power input terminal, a voltage dividing unit and a comparison unit;

[0006] The voltage dividing unit comprises an input terminal, a first output terminal and a second output terminal, and the voltage dividing unit divides the voltage inputted from the input terminal and outputs the voltage from the first output terminal and the second output terminal respectively;

[0007] A first end of the first capacitor is electrically connected to the detection input end, and a second end of the first capacitor is electrically connected to the first input end of the comparison unit;

[0008] A first end of the second capacitor is electrically connected to the first input end of the comparison unit, and a second end of the second capacitor is grounded;

[0009] A first end of the first switch unit is electrically connected to a power input end, and a second end of the first switch unit is electrically connected to a first end of the first capacitor;

[0010] A first end of the second switch unit is electrically connected to the first output end of the voltage dividing unit, and a second end of the second switch unit is electrically connected to the second end of the first capacitor;

[0011] The second output terminal of the voltage dividing unit is electrically connected to the second input terminal of the comparison unit;

[0012] The output end of the comparison unit is electrically connected to the detection output end.

[0013] Optionally, the voltage outputted by the first output terminal of the voltage divider unit is greater than the voltage outputted by the second output terminal.

[0014] Optionally, the voltage dividing unit includes a plurality of resistors connected in series between its input terminal and a ground terminal;

[0015] Two of the common connection ends of the different resistors serve as the first output end and the second output end of the voltage dividing unit respectively.

[0016] Optionally, the first switching unit adopts a first transistor, the first electrode of the first transistor serves as the first end of the first switching unit, and the second electrode of the first transistor serves as the second end of the first switching unit. The first transistor can control the conduction or disconnection between the first electrode and the second electrode according to the signal of its control electrode.

[0017] Optionally, the second switch unit adopts a second transistor, the first electrode of the second transistor serves as the first end of the second switch unit, and the second electrode of the second transistor serves as the second end of the second switch unit, and the second transistor can control the conduction or disconnection between the first electrode and the second electrode according to the signal of the control electrode.

[0018] Optionally, the comparison unit adopts a first comparator, the first input end of the first comparator serves as the first input end of the comparison unit, the second input end of the first comparator serves as the second input end of the comparison unit, and the output end of the first comparator serves as the output end of the comparison unit.

[0019] In a second aspect, an embodiment of the present invention further provides a flash memory leakage detection device, comprising any of the above leakage detection circuits and a flash memory;

[0020] The power input terminal of the leakage detection circuit is electrically connected to the pump voltage output terminal of the flash memory, and the detection input terminal of the leakage detection circuit is electrically connected to the row decoder of the flash memory.

[0021] Optionally, the flash memory includes a charge pump and a second comparator; the voltage dividing unit also includes a third output terminal;

[0022] The third output terminal of the voltage dividing unit is electrically connected to the first input terminal of the second comparator, and the second input terminal of the second comparator is used to input a reference voltage;

[0023] The output end of the second comparator is electrically connected to the input end of the charge pump, and the output end of the charge pump serves as a pump voltage output end of the flash memory.

[0024] In a third aspect, an embodiment of the present invention further provides a leakage detection method based on the above-mentioned flash memory leakage detection device, the leakage detection method comprising:

[0025] Controlling the first switch unit and the second switch unit to be turned on, so that the pump voltage output end charges the first capacitor and the second capacitor;

[0026] The first switch unit and the second switch unit are both controlled to be turned off, and the time from the turning off of the first switch unit to the flipping of the output signal of the output end of the comparison unit is recorded as the detection time.

[0027] Optionally, after recording the time from when the first switch unit is turned off to when the output signal at the output end of the comparison unit is flipped as the detection time, the method further includes:

[0028] If the detection time is less than the preset time, the block currently selected by the row decoder is marked as a bad block.

[0029] The present invention adopts a leakage detection circuit including a detection input terminal, a detection output terminal, a first capacitor, a second capacitor, a first switch unit, a second switch unit, a power input terminal, a voltage divider unit and a comparison unit. The size of the leakage current is judged by the flipping time of the output signal of the comparison unit, and the detection efficiency and accuracy are relatively high. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of a leakage detection circuit provided by an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of a circuit structure of a leakage detection circuit provided by an embodiment of the present invention;

[0032] Figure 3 A schematic diagram of the circuit structure of another leakage detection circuit provided by an embodiment of the present invention;

[0033] Figure 4 A schematic diagram of the circuit structure of another leakage detection circuit provided by an embodiment of the present invention;

[0034] Figure 5 A schematic diagram of the circuit structure of a flash memory leakage detection device provided by an embodiment of the present invention;

[0035] Figure 6 A schematic diagram of the circuit structure of another flash memory leakage detection device provided by an embodiment of the present invention;

[0036] Figure 7 A flow chart of a leakage detection method provided by an embodiment of the present invention;

[0037] Figure 8 A flow chart of another leakage detection method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0038] 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.

[0039] Example

[0040] Figure 1 A schematic diagram of a leakage detection circuit provided by an embodiment of the present invention, referring to Figure 1 The leakage detection circuit includes a detection input terminal IN, a detection output terminal OUT, a first capacitor 101, a second capacitor 102, a first switch unit 103, a second switch unit 104, a power input terminal VP, a comparison unit 105 and a voltage divider unit 106;

[0041] The voltage dividing unit 106 includes an input terminal, a first output terminal, and a second output terminal. The voltage dividing unit 106 is used to divide the voltage input from the input terminal and output it from the first output terminal and the second output terminal respectively;

[0042] A first end of the first capacitor 101 is electrically connected to the detection input terminal IN, and a second end of the first capacitor 101 is electrically connected to the first input terminal V1 of the comparison unit 105;

[0043] A first end of the second capacitor 102 is electrically connected to the first input end V1 of the comparison unit 105, and a second end of the second capacitor 102 is grounded;

[0044] A first end of the first switch unit 103 is electrically connected to the power input terminal VP, and a second end of the first switch unit 103 is electrically connected to a first end of the first capacitor 101;

[0045] A first end of the second switch unit 104 is electrically connected to the first output end of the voltage dividing unit 106 , and a second end of the second switch unit 104 is electrically connected to the second end of the first capacitor 101 ;

[0046] The second output terminal of the voltage dividing unit 106 is electrically connected to the second input terminal V2 of the comparison unit 105;

[0047] The output terminal of the comparison unit 105 is electrically connected to the detection output terminal OUT.

[0048] The voltage outputted from the first output terminal of the voltage dividing unit 106 is greater than the voltage outputted from the second output terminal thereof.

[0049] Specifically, after the input terminal IN of the leakage detection circuit is connected to the circuit to be detected, the first switch unit 103 and the second switch unit 104 are first controlled to be closed, and the power input terminal VP inputs the power signal. At this time, the power signal input to the power input terminal VP charges the first capacitor 101 through the first switch unit 103 on the one hand, and charges the second capacitor 102 through the first output terminal of the voltage divider unit 106 and the second switch unit 104 on the other hand. At the same time, the voltages of the first input terminal V1 and the second input terminal V2 of the comparison unit 105 are different. For example, the voltage of the first input terminal V1 of the comparison unit 105 is greater than the voltage of the second input terminal V2. The comparison unit 105 is The output end of 105 outputs a high level; then the first switch unit 103 and the second switch unit 104 are both turned on. If there is leakage current in the circuit to be detected, the leakage current will cause the charge of the first capacitor 101 and the second capacitor 102 to be discharged, thereby causing the voltage of the first input end V1 of the comparison unit 105 to drop, until the input voltage of the first input end V1 of the comparison unit 105 is reduced to the input voltage of the second input end V2, the output end of the comparison unit is flipped from a high level to a low level, and the time required from the opening of the first switch unit 103 and the second switch unit 104 to the flipping of the output signal of the output end of the comparison unit 105 is recorded as the detection time. Compare the detection time with the preset time. If the detection time is less than the preset time, it means that the charge of the first capacitor 103 and the second capacitor 104 is discharged faster, that is, the leakage current in the circuit to be detected is relatively large, and if the detection time is not less than the preset time, it means that the charge of the first capacitor 103 and the second capacitor 104 is discharged slower, and the leakage current in the circuit to be detected is relatively small. It is understandable that the preset time can be set according to the type of circuit to be detected or the leakage current detection standard, and this embodiment does not specifically limit this.

[0050] The technical solution of this embodiment adopts a leakage detection circuit including a detection input terminal, a detection output terminal, a first capacitor, a second capacitor, a first switch unit, a second switch unit, a power input terminal, a voltage divider unit and a comparison unit. The size of the leakage current is judged by the flipping time of the output signal of the comparison unit, and the detection efficiency and accuracy are relatively high.

[0051] Optional, reference Figure 2 , Figure 2 A schematic diagram of the circuit structure of a leakage detection circuit provided by an embodiment of the present invention, wherein the voltage dividing unit 106 includes a plurality of resistors connected in series between its input terminal and the ground terminal;

[0052] Two of the common connection terminals of the different resistors serve as the first output terminal and the second output terminal of the voltage dividing unit 106 respectively.

[0053] Exemplary, reference Figure 2, the voltage divider unit 106 includes a plurality of resistors Rm+1, Rm, ..., Rn+1, ..., R0, wherein the common connection end between R0 and R1 is used as the second output end of the voltage divider unit 106, and the common connection end between two adjacent resistors between Rm and Rn+1 is used as the first output end of the voltage divider unit 106. Different detection standards can be used for different circuits to be detected. By setting the positions of the first output end and the second output end of the voltage divider unit 106, as long as the output voltage of the first output end of the voltage divider unit 106 is greater than the output voltage of the second output end, the application range of the leakage detection circuit can be more flexible.

[0054] The technical solution of this embodiment, by adopting a voltage dividing unit including a plurality of resistors, can make the application range of the leakage detection circuit wider and the flexibility higher.

[0055] Optional, reference Figure 3 , Figure 3 A circuit structure diagram of another leakage detection circuit provided in an embodiment of the present invention, wherein the first switch unit 103 adopts a first transistor P1, the first electrode of the first transistor P1 serves as the first end of the first switch unit 103, and the second electrode of the first transistor P1 serves as the second end of the first switch unit 103, and the first transistor P1 can control the conduction or disconnection between the first electrode and the second electrode according to the signal of its control electrode.

[0056] The second switch unit 104 uses a second transistor P2, the first electrode of the second transistor P2 serves as the first end of the second switch unit 104, the second electrode of the second transistor P2 serves as the second end of the second switch unit 104, and the second transistor P2 can control the conduction or disconnection between its first electrode and the second electrode according to the signal of its control electrode.

[0057] Specifically, both the first transistor P1 and the second transistor P2 can be NMOS tubes. When the circuit to be detected is a circuit including a semiconductor structure, such as a word line in a flash memory, the first switch unit 103 and the second switch unit 104 are easier to integrate with the flash memory, and the first switch unit 103 and the second switch unit 104 use transistors, which are easier to control.

[0058] Optional, reference Figure 4 , Figure 4 A circuit structure diagram of another leakage detection circuit provided in an embodiment of the present invention, wherein the comparison unit 105 adopts a first comparator, the first input terminal of the first comparator serves as the first input terminal V1 of the comparison unit 105, the second input terminal of the first comparator serves as the second input terminal V2 of the comparison unit 105, and the output terminal of the first comparator serves as the output terminal of the comparison unit 105.

[0059] Specifically, the comparator has the function of outputting different output signals according to the magnitude of the input voltages at its two input terminals. Exemplarily, the first input terminal of the comparator is a non-inverting input terminal, and the second input terminal is an inverting input terminal. Before the first switch unit 103 and the second switch unit 104 are turned off, since the input voltage at the first input terminal of the first comparator is greater than the input voltage at the second input terminal of the first comparator, the output terminal of the first comparator outputs a high level, that is, the output terminal OUT of the leakage detection circuit outputs a high level; after the first switch unit 103 and the second switch unit 104 are both turned off, if there is a leakage current in the circuit to be detected, the input voltage at the first input terminal of the first comparator begins to decrease. When the input voltage at the first input terminal of the first comparator drops to the input voltage at the second input terminal, the output terminal of the first comparator flips to a low level, that is, the output terminal OUT of the leakage detection circuit flips to a low level. Whether the leakage current of the circuit to be detected meets the standard can be determined based on the speed of the output signal flipping time at the output terminal of the first comparator.

[0060] Optional, reference Figure 5 , Figure 5 A schematic diagram of the circuit structure of a flash memory leakage detection device provided by an embodiment of the present invention; the flash memory leakage detection device comprises any one of the above leakage detection circuits and a flash memory;

[0061] The power input terminal of the leakage detection circuit is electrically connected to the pump voltage output terminal of the flash memory, and the detection input terminal of the leakage detection circuit is electrically connected to the row decoder 202 of the flash memory.

[0062] Specifically, the flash memory includes a charge pump 201 and a row decoder 202, and the circuit structures of the charge pump 201 and the row decoder 202 are well known to those skilled in the art. The charge pump 201 is used to provide an input voltage for the flash memory, and at the same time provide a voltage for the power input terminal of the leakage detection circuit, which can improve the utilization rate of components in the flash memory and reduce costs. The row decoder 202 is used to connect the leakage detection circuit to a certain word line in the flash memory. If the leakage current of the word line is detected by the leakage detection circuit and does not meet the standard, the block where the word line is located is marked as a bad block to avoid data loss caused by users writing data into the bad block. If the leakage current of the word line is detected by the leakage detection circuit and meets the standard, the other word lines in the block where the word line is located are detected by the row decoder 202. When the leakage current of all word lines in the block meets the standard, the block can be marked as a normal block.

[0063] The technical solution of this embodiment can detect leakage in the flash memory in time by adopting a leakage detection device including a leakage detection circuit and a flash memory, thereby avoiding data loss and causing losses to users.

[0064] Optional, reference Figure 6 , Figure 6 A schematic diagram of the circuit structure of another flash memory leakage detection device provided by an embodiment of the present invention;

[0065] The flash memory includes a charge pump 201 and a second comparator 203, and the voltage dividing unit 106 also includes a third output terminal;

[0066] The third output terminal of the voltage dividing unit 203 is electrically connected to the first input terminal of the second comparator 203, and the second input terminal of the second comparator 203 is used to input a reference voltage;

[0067] The output end of the second comparator 203 is electrically connected to the input end of the charge pump 201 , and the output end of the charge pump 201 serves as a pump voltage output end of the flash memory.

[0068] Specifically, the charge pump 201 may also include a peripheral circuit composed of a second comparator 203, which is used to adjust the output voltage of the charge pump 201. The first input terminal of the second comparator 203 is electrically connected to the third output terminal of the voltage divider unit 106, which can further improve the utilization rate of components in the leakage detection device and reduce costs.

[0069] Optional, reference Figure 7 , Figure 7 A flowchart of a leakage detection method provided by an embodiment of the present invention can be applied to Figure 6 A flash memory leakage detection device in the present invention, wherein the leakage detection method comprises:

[0070] Step 301, controlling the first switch unit and the second switch unit to be turned on, so that the pump voltage output end charges the first capacitor and the second capacitor;

[0071] Step 302: Control the first switch unit and the second switch unit to be turned off, and record the time from the first switch unit being turned off to the output signal at the output end of the comparison unit being flipped as the detection time.

[0072] Specifically, the first switch unit and the second switch unit are turned on or off at the same time. The working principle is the same as the detection principle in the above leakage detection circuit, which will not be repeated here.

[0073] Optional, reference Figure 8 , Figure 8 A flowchart of another leakage detection method provided in an embodiment of the present invention can be applied to Figure 6 A flash memory leakage detection device in the present invention, wherein the leakage detection method comprises:

[0074] Step 401, controlling the first switch unit and the second switch unit to be turned on, so that the pump voltage output end charges the first capacitor and the second capacitor;

[0075] Step 402, control the first switch unit and the second switch unit to be turned off, and record the time from the first switch unit being turned off to the output signal of the output end of the comparison unit being flipped as the detection time;

[0076] Step 403: If the detection time is less than the preset time, the block currently selected by the row decoder is marked as a bad block.

[0077] 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 leakage detection circuit, characterized in that: The leakage detection circuit comprises: a detection input terminal, a detection output terminal, a first capacitor, a second capacitor, a first switch unit, a second switch unit, a power input terminal, a voltage dividing unit and a comparison unit; The voltage dividing unit comprises an input terminal, a first output terminal and a second output terminal, and the voltage dividing unit is used to divide the voltage inputted from the input terminal and output it from the first output terminal and the second output terminal respectively; A first end of the first capacitor is electrically connected to the detection input end, and a second end of the first capacitor is electrically connected to the first input end of the comparison unit; A first end of the second capacitor is electrically connected to the first input end of the comparison unit, and a second end of the second capacitor is grounded; A first end of the first switch unit is electrically connected to a power input end, and a second end of the first switch unit is electrically connected to a first end of the first capacitor; A first end of the second switch unit is electrically connected to the first output end of the voltage dividing unit, and a second end of the second switch unit is electrically connected to the second end of the first capacitor; The second output terminal of the voltage dividing unit is electrically connected to the second input terminal of the comparison unit; The output end of the comparison unit is electrically connected to the detection output end; The voltage outputted by the first output terminal of the voltage dividing unit is greater than the voltage outputted by the second output terminal; The first switch unit adopts a first transistor, the first electrode of the first transistor serves as the first end of the first switch unit, the second electrode of the first transistor serves as the second end of the first switch unit, and the first transistor can control the conduction or disconnection between the first electrode and the second electrode according to the signal of its control electrode.

2. The leakage detection circuit according to claim 1, characterized in that: The voltage dividing unit includes a plurality of resistors connected in series between its input terminal and the ground terminal; Two of the common connection ends of the different resistors serve as the first output end and the second output end of the voltage dividing unit respectively.

3. The leakage detection circuit according to claim 1, characterized in that: The second switch unit adopts a second transistor, the first electrode of the second transistor serves as the first end of the second switch unit, the second electrode of the second transistor serves as the second end of the second switch unit, and the second transistor can control the conduction or disconnection between the first electrode and the second electrode according to the signal of the control electrode.

4. The leakage detection circuit according to claim 1, characterized in that: The comparison unit adopts a first comparator, the first input end of the first comparator serves as the first input end of the comparison unit, the second input end of the first comparator serves as the second input end of the comparison unit, and the output end of the first comparator serves as the output end of the comparison unit.

5. A flash memory leakage detection device, characterized in that: A leakage detection circuit and a flash memory comprising any one of claims 1 to 4; The power input terminal of the leakage detection circuit is electrically connected to the pump voltage output terminal of the flash memory, and the detection input terminal of the leakage detection circuit is electrically connected to the row decoder of the flash memory.

6. The flash memory leakage detection device according to claim 5, characterized in that: The flash memory includes a charge pump and a second comparator; the voltage dividing unit also includes a third output terminal; The third output terminal of the voltage dividing unit is electrically connected to the first input terminal of the second comparator, and the second input terminal of the second comparator is used to input a reference voltage; The output end of the second comparator is electrically connected to the input end of the charge pump, and the output end of the charge pump serves as a pump voltage output end of the flash memory.

7. A leakage detection method based on the flash memory leakage detection device according to claim 6, characterized in that: The leakage detection method comprises: Controlling the first switch unit and the second switch unit to be turned on, so that the pump voltage output end charges the first capacitor and the second capacitor; The first switch unit and the second switch unit are both controlled to be turned off, and the time from the turning off of the first switch unit to the flipping of the output signal of the output end of the comparison unit is recorded as the detection time.

8. The leakage detection method according to claim 7, characterized in that: After recording the time from when the first switch unit is turned off to when the output signal at the output end of the comparison unit is flipped as the detection time, the method further includes: If the detection time is less than the preset time, the block currently selected by the row decoder is marked as a bad block.

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