Electrostatic discharge protection device and electrostatic discharge protection method

Abstract

An electrostatic discharge (ESD) protection device is disclosed. This ESD protection device is used to protect internal circuitry. The ESD protection device includes an ESD protection array and a control circuit. The ESD protection array includes a plurality of ESD protection units. The control circuit is coupled to the ESD protection array, wherein the control circuit is used to control the conduction of each of the plurality of ESD protection units, so that a certain number of the plurality of ESD protection units are turned on.

Description

Technical Field

[0001] The embodiments described in this disclosure relate to an electrostatic discharge protection device and an electrostatic discharge protection method, particularly an electrostatic discharge protection device and an electrostatic discharge protection method that dynamically adjusts the number of conducting electrostatic discharge protection units. Prior Technology

[0002] Electrostatic discharge (ESD) occurs when two objects with different charges come into contact. For example, an ESD event occurs when a pad in the internal circuitry of an electronic device comes into contact with a charged object, such as a human body or a circuit board. In this case, a strong discharge current is induced on the pad in the internal circuitry, discharging the charge accumulated in the internal circuitry or the object being charged. To protect the components in the internal circuitry of electronic devices from damage caused by strong and concentrated discharge currents, ESD protection circuitry is typically added to the internal circuitry of electronic devices.

[0003] For electrostatic discharge (ESD) protection circuits, the more ESD paths there are, the shorter the required discharge time, and the stronger the circuit's robustness. On the other hand, if there are more ESD paths in the circuit (or more diodes used in those paths), the parasitic capacitance will be larger, and the signal efficiency of the internal circuitry will be severely reduced.

[0004] Therefore, improving the performance of electrostatic discharge (ESD) protection circuits while reducing their parasitic capacitance is a problem that needs to be solved. Various methods have been proposed to address this issue. However, there is a physical conflict between improving the efficiency of ESD protection circuits and simultaneously reducing their parasitic capacitance. Summary of the Invention

[0005] Some embodiments disclosed herein relate to an electrostatic discharge (ESD) protection device for protecting internal circuitry. The ESD protection device includes an ESD protection array and a control circuit. The ESD protection array includes multiple ESD protection units. The control circuit is coupled to the ESD protection array and controls the conduction of each of the multiple ESD protection units to ensure that a specified number of the multiple ESD protection units are turned on.

[0006] Some embodiments disclosed herein relate to an electrostatic discharge (ESD) protection method. This ESD protection method is applicable to an ESD protection device. The ESD protection device is used to protect internal circuitry. The ESD protection method includes the following steps: receiving a control message from a control circuit of the ESD protection device, wherein the control message includes a protection level and a determination number; and controlling the conduction of each of a plurality of ESD protection units in an ESD protection array of the ESD protection device according to the control message, so that a determination number of the plurality of ESD protection units is turned on. Simple Explanation of the Diagram

[0007] To make the above and other objects, features, advantages and embodiments of this disclosure more apparent and understandable, the accompanying drawings are described below: Figure 1 is a schematic diagram of an electronic device illustrated according to some embodiments of the present disclosure. Figure 2 is a schematic diagram of an electrostatic discharge protection array illustrated according to some embodiments of the present disclosure. Figure 3 is a flowchart illustrating an electrostatic discharge protection method according to some embodiments of this disclosure. Figure 4 is a schematic diagram of a switch array illustrated according to some embodiments of the present disclosure. Figure 5 is a schematic diagram of a switching unit illustrated according to some embodiments of the present disclosure. Implementation

[0008] The following disclosure provides numerous different embodiments or examples for implementing various features of this disclosure. Elements and arrangements in the specific examples are used in the following discussion to simplify this disclosure. Any examples discussed are for illustrative purposes only and do not in any way limit the scope or meaning of this disclosure or its examples. Where appropriate, the same reference numerals are used between figures and in corresponding text descriptions to represent the same or similar elements.

[0009] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms "a," "an," and "the" are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "including," or "comprising" and / or "including," or "having" and / or "having," when used in this specification, specify the presence, area, integer, step, operation, element, and / or component of the stated features, but do not exclude the presence or addition of one or more other features, areas, integers, steps, operations, elements, components, and / or groups thereof.

[0010] In this document, the term "coupled" may also refer to "electrically coupled," and the term "connected" may refer to "electrically connected." "Coupled" and "connected" may also be used to indicate that two or more elements cooperate or interact with each other.

[0011] Please refer to Figure 1. Figure 1 is a schematic diagram illustrating an electronic device 1 according to some embodiments of this disclosure. The electronic device 1 includes internal circuitry 20 and electrostatic discharge protection device 10. The internal circuitry 20 is coupled to the electrostatic discharge protection device 10.

[0012] In some embodiments, the electrostatic discharge protection device 10 includes a control circuit 150 and an electrostatic discharge protection array 170. The control circuit 150 is coupled to the electrostatic discharge protection array 170.

[0013] In some embodiments, the electrostatic discharge protection device 10 further includes a detection circuit 110 and a logic circuit 130. The detection circuit 110 is coupled to the logic circuit 130, and the logic circuit 130 is coupled to the control circuit 150.

[0014] Please refer to Figure 2. Figure 2 is a schematic diagram illustrating an electrostatic discharge (ESD) protection array 170 according to some embodiments of this disclosure. As shown in Figure 2, the ESD protection array 170 is coupled to a control circuit 150. The ESD protection array 170 includes a plurality of ESD protection units EU11 to EUNN. The plurality of ESD protection units EU11 to EUNN are arranged in rows and columns.

[0015] One end of the electrostatic discharge protection array 170 is coupled to the power supply VDD, and the other end of the electrostatic discharge protection array 170 is coupled to the power supply VSS. In some embodiments, the power supply VSS is the ground terminal.

[0016] As shown in Figure 2, some of the electrostatic discharge protection units EU11 to EUNN are connected in series, while some of the electrostatic discharge protection units EU11 to EUNN are connected in parallel. For example, electrostatic discharge protection units EU11 and EU12 are connected in series, while electrostatic discharge protection units EU11 and EU21 are connected in parallel.

[0017] The detailed steps of the electrostatic discharge protection device 10 will be explained in detail below with reference to Figure 3.

[0018] The electrostatic discharge protection device 10 shown in Figure 1 is for illustrative purposes only, and the embodiments of the present invention are not intended to limit the scope thereof. The steps of the electrostatic discharge protection device 10 shown in Figure 1 will be described in detail below with reference to Figure 3.

[0019] Please also refer to Figure 3. Figure 3 is a flowchart illustrating an electrostatic discharge protection method 300 according to some embodiments of this disclosure. The electrostatic discharge protection method 300 includes steps S310 and S330. These steps are for illustrative purposes, and more steps are also expected within the scope of this disclosure.

[0020] In step S310, a control message is received. In some embodiments, in step S310, the control circuit 150 shown in Figure 1 transmits the control message to the electrostatic discharge protection array 170 shown in Figure 1.

[0021] In some embodiments, the detection circuit 110, as illustrated in Figure 1, detects the voltage or current value of the internal circuit 20. In some embodiments, the voltage or current value is an input voltage or input current value input to the internal circuit 20 from other circuits (not shown) of the electronic device 1.

[0022] In some embodiments, the detection circuit 110 transmits the detected voltage value or the detected current value of the internal circuit 20 to the logic circuit 130. The logic circuit 130 determines the number of determinations based on the detected voltage value or the detected current value. In some embodiments, the logic circuit 130 further determines the continuity of each of the plurality of electrostatic discharge protection units EU11 to EUNN based on the detected voltage value or the detected current value.

[0023] In some embodiments, the logic circuit 130 determines the corresponding protection value based on the detected voltage or current value. The higher the protection value, the higher the number of determinations, and the more electrostatic discharge protection units EU11 to EUNN are activated. The more electrostatic discharge protection units EU11 to EUNN are activated, the better the electrostatic discharge protection efficiency. However, when more electrostatic discharge protection units EU11 to EUNN are activated, the inductance and capacitance are larger, and the message transmission quality is worse.

[0024] In one embodiment, according to Table 1 below, the logic circuit 130 determines the number of electrostatic discharge protection units EU11 to EUNN that are turned on. Table 1 shown below is for illustrative purposes only, and the embodiments of the present invention are not limited thereto.

[0025] Table 1 voltage value protection level Quantity of judgment voltage value First threshold 3 (High) 10 First threshold voltage value Second threshold 2 6 Second threshold voltage value 1 (Low) 4

[0026] According to Table 1, for example, when the voltage value is less than the second threshold, the corresponding protection level is level 1, and the number of determinations is 4. In one embodiment, Table 1 further includes the electrostatic discharge protection units that are turned on. For example, in one embodiment, when the number of determinations is 4, electrostatic discharge protection units EU11, EU21, EU12 and EU22 are turned on.

[0027] In some embodiments, the logic circuit 130 includes an ADC (Analog-to-Digital Converter) circuit. The ADC circuit converts the voltage or current value detected by the detection circuit 110 into digital information, and the logic circuit 130 determines the protection level or the number of protection decisions based on the digital information.

[0028] In some other embodiments, logic circuit 130 receives a command message, and logic circuit 130 determines the conduction of each of the plurality of electrostatic discharge protection units EU11 to EUNN based on the command message, and determines the number of determinations.

[0029] In some embodiments, the command message includes information about the allowable capacitance value. Based on the allowable capacitance value, the logic circuit determines the number of checks and which electrostatic discharge protection units should be activated.

[0030] For example, in one embodiment, the allowable capacitance value corresponding to the determination quantity is 4. When the determination quantity is 4, electrostatic discharge protection units EU11, EU21, EU12, and EU22 are determined to be turned on. That is, four of the electrostatic discharge protection units EU11 to EUNN are turned on.

[0031] In some embodiments, the higher the allowable capacitance value, the higher the level of protection, and multiple electrostatic discharge protection units EU11 to EUNN are determined to be turned on.

[0032] In some other embodiments, the command message includes information about the operational phase of the internal circuitry 20. For example, in some embodiments, the command message includes information about whether the internal circuitry 20 is operating in the startup phase.

[0033] According to the command message, when the internal circuit 20 is operating in the startup phase and the change in the operating voltage of the internal circuit 20 is higher than the change threshold, that is, when the operating voltage of the internal circuit 20 is unstable, a first number of electrostatic discharge protection units EU11 to EUNN are turned on. On the other hand, according to the command message, when the internal circuit is not operating in the startup phase and the change in the operating voltage of the internal circuit 20 is not higher than the change threshold, that is, when the operating voltage of the internal circuit 20 is stable, a second number of electrostatic discharge protection units EU11 to EUNN are turned on. The first number is greater than the second number.

[0034] In some embodiments, logic circuit 130 determines the number of electrostatic discharge protection units EU11 to EUNN to be turned on according to Table 2 below. Table 2 shown below is for illustrative purposes only, and the embodiments of the present invention are not limited thereto.

[0035] Table 2 Operational phase protection level Quantity of judgment Start-up phase 2 (High) 10 General Stage 1 (Low) 6

[0036] According to Table 2, when the internal circuit 20 is operating in the startup phase, the corresponding protection level is Level 2, and the number of judgments is 10. That is, 10 of the electrostatic discharge protection units EU11 to EUNN are activated. On the other hand, when the internal circuit 20 is not operating in the startup phase or in the normal phase, the corresponding protection level is Level 1, and the number of judgments is 6. That is, 6 of the electrostatic discharge protection units EU11 to EUNN are activated.

[0037] In some embodiments, the command message includes information on whether the internal circuitry 20 is operating in the data writing phase, data reading phase, or idle phase.

[0038] In some other embodiments, when the internal circuit 20 is operating in the data reading phase, a third number of electrostatic discharge protection units EU11 to EUNN are turned on. On the other hand, when the internal circuit 20 is operating in the idle phase, a fourth number of electrostatic discharge protection units EU11 to EUNN are turned on. The third number is less than the fourth number.

[0039] In some embodiments, the logic circuit 130 determines the number of electrostatic discharge protection units EU11 to EUNN to be turned on according to Table 3 below. Table 3 shown below is for illustrative purposes only, and the implementation of the embodiments of the present invention is not limited thereto.

[0040] Table 3 Operational phase protection level Quantity of judgment Idle phase 2 (High) 10 Data reading stage or data writing stage 1 (Low) 6

[0041] According to Table 3, when the internal circuit 20 is operating in the idle phase, the corresponding protection level is Level 2, and the number of judgments is 10. That is, 10 of the electrostatic discharge protection units EU11 to EUNN are turned on. On the other hand, when the internal circuit 20 is operating in the data reading or data writing phase, the corresponding protection level is Level 1, and the number of judgments is 6. That is, 6 of the electrostatic discharge protection units EU11 to EUNN are turned on.

[0042] In some other embodiments, the command message includes information about the operating mode of the internal circuitry 20. The operating mode includes a high-speed transmission mode or a low-speed transmission mode.

[0043] When the internal circuit 20 operates in high-speed transmission mode, the fifth number of electrostatic discharge protection units EU11 to EUNN are turned on. On the other hand, when the internal circuit 20 operates in low-speed transmission mode, the sixth number of electrostatic discharge protection units EU11 to EUNN are turned on. The fifth number is less than the sixth number.

[0044] In some embodiments, according to Table 4 shown below, the logic circuit 130 determines the number of electrostatic discharge protection units EU11 to EUNN that are turned on. Table 4 shown below is for illustrative purposes only, and the implementation of this invention is not limited thereto.

[0045] Table 4 Operating mode protection level Quantity of judgment Low-speed transmission mode 2 (High) 10 High-speed transmission mode 1 (Low) 6

[0046] According to Table 4, when the internal circuit 20 operates in low-speed transmission mode, the corresponding protection level is Level 2, and the number of decisions is 10. Ten of the electrostatic discharge protection units EU11 to EUNN are activated. On the other hand, when the internal circuit 20 operates in high-speed transmission mode, the corresponding protection level is Level 1, and the number of decisions is 6. That is, six of the electrostatic discharge protection units EU11 to EUNN are activated.

[0047] In some embodiments, the high-speed transmission mode includes the internal circuitry 20 receiving messages via a high-speed transmission interface, while the low-speed transmission mode includes the internal circuitry 20 receiving messages via a low-speed transmission interface.

[0048] In some embodiments, the command message directly includes information on the degree of protection or the number of conduction units in the electrostatic discharge protection units EU11 to EUNN.

[0049] Please refer again to Figure 1. In some embodiments, after the logic circuit 130 determines the protection level or the number of electrostatic discharge protection units EU11 to EUNN that are turned on based on the command message or the current value or voltage value detected by the detection circuit 110, the logic circuit 130 generates a control message that meets the protection level or the number of determinations and transmits the control message to the control circuit 150. The control circuit 150 receives the control message from the logic circuit 130.

[0050] In some embodiments, the logic circuit 130 further includes memory. The memory stores Tables 1 to 4 as described above.

[0051] In some embodiments, the information contained in the command message is detected by the detection circuit 110. That is, the detection circuit 110 detects the operation stage or operation mode of the internal circuit 20 and generates a command message based on the operation stage or operation mode of the internal circuit 20.

[0052] In step S330, the conduction of each of the plurality of electrostatic discharge protection units EU11 to EUNN in the electrostatic discharge protection array 170 of the electrostatic discharge protection device 10 is controlled according to the control message, so that a certain number of the plurality of electrostatic discharge protection units EU11 to EUNN are turned on. In some embodiments, step S330 is performed by the control circuit 150 as shown in Figure 1.

[0053] Please also refer to Figure 4. Figure 4 is a schematic diagram illustrating a switch array 400 according to some embodiments of this disclosure. In some embodiments, the control circuit 150 as illustrated in Figure 1 includes the switch array 400, which is connected to the internal circuitry 20.

[0054] In some embodiments, as illustrated in Figure 4, the switch array includes switch units C11 to CNN. Detailed implementations of switch units C11 to CNN will be described in detail with reference to Figure 5.

[0055] Figure 5 is a schematic diagram of a switching unit C11 according to some embodiments of the present disclosure. As shown in Figure 5, the control terminal of the switching unit C11 is coupled to a voltage value Y1, the first terminal of the switching unit C11 is coupled to a voltage value X1, and the second terminal of the switching unit C11 is coupled to an electrostatic discharge protection unit EU11. By controlling the voltage values ​​X1 and Y1, the conduction of the electrostatic discharge protection unit EU11 can be controlled.

[0056] Other switching units are similar to switching unit C11 and will not be described in detail here. By controlling the voltage values ​​X1 to XN and Y1 to YN shown in Figure 4, the control circuit 150 controls the conduction of each electrostatic discharge protection unit EU11 to EUNN.

[0057] In some other embodiments, the switching units of C11 to CNN can be fuses. By blowing or not blowing the fuses, the control circuit 150 controls the conductivity of each electrostatic discharge protection unit EU11 to EUNN.

[0058] Each electrostatic discharge (ESD) protection unit EU11 to EUNN shown in Figure 2 is a circuit containing at least one diode connected between power supply VDD and power supply VSS. When one of the ESD protection units EU11 to EUNN is turned on, at least one diode contained in that ESD protection unit is turned on. When the internal circuit 20 shown in Figure 1 is subjected to an ESD attack, the electrostatic current flows through at least one diode to power supply VDD or power supply VSS to protect the internal circuit 20 from ESD damage.

[0059] In previous embodiments, the number of electrostatic discharge protection units EU11 to EUNN that were turned on could not be dynamically adjusted. However, in the embodiments of this invention, the conductivity of each of the electrostatic discharge protection units EU11 to EUNN can be dynamically adjusted, and the parasitic capacitance value generated by turning on the electrostatic discharge protection unit can also be adjusted accordingly.

[0060] In summary, the embodiments of this invention provide an electrostatic discharge (ESD) protection device and an ESD protection method. By dynamically adjusting the conductivity of each ESD protection unit in the ESD protection array, the parasitic capacitance value generated by the conductive ESD protection unit can be adjusted accordingly, and the signal quality can be improved. The embodiments of this invention are applicable to electronic devices of different specifications and can meet the needs of different customers.

[0061] In some embodiments, electronic device 1 may be dynamic random access memory (DRAM), but the embodiments of the present invention are not limited thereto.

[0062] In some embodiments, the internal circuit 20 may be a receiving circuit, but the implementation of the present invention is not limited thereto.

[0063] Although the embodiments described herein have been described in considerable detail, other embodiments are possible. Therefore, the scope of the appended claims should not be limited to the embodiments described herein.

[0064] Furthermore, the above examples include sequential exemplary steps, but these steps need not be performed in the order shown. Performing these steps in different orders is within the scope of this disclosure. Within the spirit and scope of the embodiments of this disclosure, these steps may be added, substituted, changed in order, and / or omitted as appropriate.

[0065] Although the present disclosure has been described above with reference to embodiments, it is not intended to limit the present disclosure. Any person with ordinary knowledge in the art may make various modifications and refinements without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the appended claims.

[0066] 1: Electronic devices 10: Electrostatic discharge protection device 20: Internal Circuitry 110: Detection circuit 130: Logic Circuits 150: Control Circuit 170: Electrostatic Discharge Protection Array VDD: Power Supply VSS: Power Supply EU11, EU12, EU1N, EU21, EU22, EU2N, EUN1, EUN2, EUNN: Electrostatic Discharge Protection Unit 300: Electrostatic Discharge Protection Methods S310, S330: Steps 400: Switch Array C11, C12, C21, CNN: Switching Units X1, X2, X3, XN: Voltage values Y1, Y2, Y3, YN: Voltage values

Claims

1. An electrostatic discharge (ESD) protection device for protecting an internal circuit, wherein the ESD protection device comprises: an ESD protection array including a plurality of ESD protection units; and a control circuit coupled to the ESD protection array, wherein the control circuit controls the conduction of each of the ESD protection units to enable a predetermined number of the ESD protection units to be turned on; wherein a first number of the ESD protection units are turned on when the internal circuit is operating in a startup phase and a change in a working voltage of the internal circuit is higher than a change threshold, and a second number of the ESD protection units are turned on when the internal circuit is not operating in the startup phase and the change in the working voltage of the internal circuit is not higher than the change threshold, wherein the first number is greater than the second number.

2. The electrostatic discharge protection device as claimed in claim 1, wherein the electrostatic discharge protection units include a first electrostatic discharge protection unit, a second electrostatic discharge protection unit, and a third electrostatic discharge protection unit, wherein the first electrostatic discharge protection unit and the second electrostatic discharge protection unit are connected in series, and the first electrostatic discharge protection unit and the third electrostatic discharge protection unit are connected in parallel.

3. The electrostatic discharge protection device as claimed in claim 1 further comprises: a logic circuit coupled to the control circuit, wherein the logic circuit is configured to determine the conduction of each of the electrostatic discharge protection units and the determination quantity based on a voltage value or a current value of the internal circuit.

4. The electrostatic discharge protection device as claimed in claim 3 further includes: a detection circuit for detecting the voltage value or the current value of the internal circuit.

5. The electrostatic discharge protection device as claimed in claim 1, wherein a third number of the electrostatic discharge protection units are turned on when the internal circuit is operating in a data reading phase or a data writing phase, and a fourth number of the electrostatic discharge protection units are turned on when the internal circuit is operating in an idle phase, wherein the third number is less than the fourth number.

6. The electrostatic discharge protection device as claimed in claim 1, wherein when the internal circuit operates in a high-speed transmission mode, a third number of the electrostatic discharge protection units are turned on, and wherein when the internal circuit operates in a low-speed transmission mode, a fourth number of the electrostatic discharge protection units are turned on, wherein the third number is less than the fourth number.

7. An electrostatic discharge (ESD) protection method applicable to an ESD protection device, wherein the ESD protection device is used to protect an internal circuit, wherein the ESD protection method comprises: receiving a control message by a control circuit of the ESD protection device, wherein the control message includes a protection level and a determination quantity; controlling the conduction of each of a plurality of ESD protection units in an ESD protection array of the ESD protection device according to the control message, such that the determination quantity of the ESD protection units is turned on; turning on a first quantity of the ESD protection units when the internal circuit is operating in a startup phase and a change in a working voltage of the internal circuit is higher than a change threshold; and turning on a second quantity of the ESD protection units when the internal circuit is not operating in the startup phase and the change in the working voltage of the internal circuit is not higher than the change threshold; wherein the first quantity is greater than the second quantity.

8. The electrostatic discharge protection method as claimed in claim 7, wherein the electrostatic discharge protection units include a first electrostatic discharge protection unit, a second electrostatic discharge protection unit, and a third electrostatic discharge protection unit, wherein the first electrostatic discharge protection unit and the second electrostatic discharge protection unit are connected in series, and the first electrostatic discharge protection unit and the third electrostatic discharge protection unit are connected in parallel.

9. The electrostatic discharge protection method as claimed in claim 7 further comprises: determining the conductivity of each of the electrostatic discharge protection units and the number of determinations based on a voltage value or a current value of the internal circuit.

10. The electrostatic discharge protection method as claimed in claim 9 further comprises: detecting the voltage value or the current value of the internal circuit by a detection circuit.

11. The electrostatic discharge protection method as claimed in claim 7 further comprises: when the internal circuit is operating in a data reading phase or a data writing phase, turning on a third number of the electrostatic discharge protection units; and when the internal circuit is operating in an idle phase, turning on a fourth number of the electrostatic discharge protection units; wherein the third number is less than the fourth number.

12. The electrostatic discharge protection method as claimed in claim 7 further comprises: when the internal circuit operates in a high-speed transmission mode, activating a third number of the electrostatic discharge protection units; and when the internal circuit operates in a low-speed transmission mode, activating a fourth number of the electrostatic discharge protection units; wherein the third number is less than the fourth number.

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