Driving output circuit, chip and driving output method based on series termination matching

Abstract

The present invention provides a drive output circuit, chip, and drive output method based on series termination matching. The drive output circuit based on series termination matching includes: a signal drive output module for driving and outputting the signal to be driven; the signal drive output module includes a termination resistor; a first electrostatic current discharge module for providing a first discharge path for the electrostatic current generated by the signal drive output module; a second electrostatic current discharge module, connected in series with the termination resistor, for providing a second discharge path for the electrostatic current; and a power clamp protection module for conducting the first and second discharge paths when the power supply voltage of the signal drive output module exceeds the clamp voltage. The present invention provides different discharge paths, effectively reducing the withstand voltage of the protected device through voltage division, thereby improving the electrostatic protection capability.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated circuit design, and in particular relates to a drive output circuit, a chip and a drive output method based on series termination matching. Background Art

[0002] Stub series terminated (SST) drivers, with their simple structure, low power consumption, and full compatibility with CMOS (Complementary Metal-Oxide-Semiconductor) processes, are widely used in various high-speed data interfaces. With the increasing demand for interconnect transmission speeds, the process technology used in interconnect interfaces has advanced from deep submicron to nanometer technology, and an increasing number of interface circuits are implemented using thin-gate devices. However, the fragility of thin-gate devices poses greater challenges to ESD protection.

[0003] Existing series-terminated output drivers primarily utilize a pair of diodes and a power clamp protection circuit for ESD protection. For example, when a positive ESD voltage is applied between the output port and ground, current flows through the forward conduction of a P-type diode, initially to the positive power supply terminal. The power clamp protection circuit then detects the voltage increase at the positive power supply terminal and activates its protection circuit, discharging the current to ground, thereby protecting the internal components. In this ESD mode, the NMOS (N-metal-oxide-semiconductor) device in the series-terminated output driver is the most susceptible to ESD damage. In the opposite ESD mode, where a positive ESD voltage is applied between the positive power supply terminal and the output port, the PMOS (positive-channel metal-oxide-semiconductor) device in the series-terminated output driver is the most susceptible to ESD damage.

[0004] Under HBM (Human Body Model) 2kV electrostatic test conditions, the maximum current is approximately 1.3A. The impedance of the power clamp protection circuit can be less than 1 ohm, making the voltage difference of the power clamp protection circuit less than or equal to 1V. In modern nanoscale CMOS processes, the gate oxide breakdown voltage of thin-gate devices is typically less than or equal to 3V. Therefore, to protect NMOS devices from damage, for example, the gate oxide breakdown voltage is less than or equal to 3V. The impedance of the P-type diode needs to be on the order of 1 ohm, that is, V = 0.7V + 1.3A * 1ohm = 2.0V, where 0.7V is the forward turn-on voltage of the diode. Therefore, a larger P-type diode is required, which results in excessive capacitive load, deteriorating signal integrity, ultimately affecting signal transmission speed and wasting power.

[0005] Therefore, how to provide a driving output circuit, chip and driving output method based on series termination matching to solve the defects of the existing technology that cannot provide higher electrostatic protection capability for series termination matching output drivers has become a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a drive output circuit, chip and drive output method based on series termination matching, which is used to solve the problem that the prior art cannot provide higher electrostatic protection capability for the series termination matching output driver.

[0007] To achieve the above-mentioned objectives and other related objectives, the present invention provides, on one hand, a drive output circuit based on series termination matching, wherein an external signal to be driven is input into the drive output circuit based on series termination matching for drive output; the drive output circuit based on series termination matching includes: a signal drive output module for driving and outputting the signal to be driven; the signal drive output module includes a termination resistor; a first electrostatic current discharge module for providing a first discharge path for the electrostatic current generated on the signal drive output module; a second electrostatic current discharge module, connected in series with the termination resistor, for providing a second discharge path for the electrostatic current and protecting internal components from damage; a power clamping protection module, connected to the first electrostatic current discharge module and the second electrostatic current discharge module respectively, for connecting the first discharge path and the second discharge path when the power supply voltage of the signal drive output module exceeds the clamping voltage, so as to connect the path between the positive pole of the power supply and the ground, discharge the electrostatic current, and provide electrostatic protection for the signal drive output module.

[0008] In one embodiment of the present invention, the first electrostatic current discharge module includes a first P-end protection unit and a first N-end protection unit; one end of the first P-end protection unit is connected to the positive pole of the power supply, and the other end is connected to one end of the first N-end protection unit; the other end of the first N-end protection unit is connected to the ground.

[0009] In one embodiment of the present invention, the first P-end protection unit is a first P-end protection diode, and the first N-end protection unit is a first N-end protection diode; the cathode of the first P-end protection diode is connected to the positive pole of the power supply, and the anode is connected to the cathode of the first N-end protection diode; the anode of the first N-end protection diode is connected to the ground; wherein, the connection point between the first P-end protection diode and the first N-end protection diode is the output port of the drive output circuit; the first P-end protection diode is used to be turned on when a forward electrostatic voltage is generated between the output port and the positive pole of the power supply, providing a first discharge path for the electrostatic current; the first N-end protection diode is used to be turned on when a forward electrostatic voltage is generated between the ground and the output port, providing a first discharge path for the electrostatic current.

[0010] In one embodiment of the present invention, the second electrostatic current discharge module includes a second P-end protection unit and a second N-end protection unit; one end of the second P-end protection unit is connected to the positive pole of the power supply, and the other end is connected to the signal drive output module; one end of the second N-end protection unit is connected to the signal drive output module, and the other end is connected to the ground.

[0011] In one embodiment of the present invention, the second P-terminal protection unit includes a second P-terminal protection diode, and the second N-terminal protection unit includes a second N-terminal protection diode; the cathode of the second P-terminal protection diode is connected to the positive pole of the power supply, and the anode is connected to the signal drive output module; the second P-terminal protection diode is used to be turned on when a forward electrostatic voltage is generated between the output port and the positive pole of the power supply, providing a second discharge path for the electrostatic current; the anode of the second N-terminal protection diode is connected to the ground, and the cathode is connected to the signal drive output module; the second N-terminal protection diode is used to be turned on when a forward electrostatic voltage is generated between the ground and the output port, providing a second discharge path for the electrostatic current.

[0012] In one embodiment of the present invention, the signal drive output module includes a P-end drive unit and an N-end drive unit; the connection point between the P-end drive unit and the N-end drive unit is the output port of the drive output circuit; the P-end drive unit and the N-end drive unit are used to perform voltage division driving on the signal to be driven; the anode of the second P-end protection diode is connected to the N-end drive unit; and the cathode of the second N-end protection diode is connected to the P-end drive unit.

[0013] In one embodiment of the present invention, a voltage range driven by the P-end driving unit is greater than a voltage range driven by the N-end driving unit.

[0014] In one embodiment of the present invention, the P-end driving unit includes a PMOS tube and a P-end resistor; wherein the P-end resistor is a first termination resistor; the source of the PMOS tube is connected to the positive electrode of the power supply, the gate is used to receive the drive signal, and the drain is connected to one end of the P-end resistor; the other end of the P-end resistor is connected to the N-end driving unit.

[0015] In one embodiment of the present invention, the PMOS transistor process uses a thin-gate device.

[0016] In one embodiment of the present invention, one end of the P-terminal resistor is connected to the cathode of the second N-terminal protection diode, and the P-terminal resistor is used to form the second discharge path with the conductive second N-terminal protection diode when a forward electrostatic voltage is generated between the ground and the output port.

[0017] In one embodiment of the present invention, the P-end driving unit further includes: a first inverter; the first inverter is used to receive and drive the to-be-driven signal, and the output end of the first inverter is connected to the gate of the PMOS tube.

[0018] In one embodiment of the present invention, the N-terminal driving unit includes: an NMOS tube and an N-terminal resistor; wherein the N-terminal resistor is a second termination resistor; the source of the NMOS tube is connected to the ground, the gate is used to receive the drive signal, the drain is connected to one end of the N-terminal resistor, and the other end of the N-terminal resistor is connected to the P-terminal driving unit.

[0019] In one embodiment of the present invention, the NMOS transistor process uses a thin-gate device.

[0020] In one embodiment of the present invention, one end of the N-terminal resistor is connected to the anode of the second P-terminal protection diode, and the N-terminal resistor is used to form the second discharge path with the conductive second P-terminal protection diode when a forward electrostatic voltage is generated between the output port and the positive electrode of the power supply.

[0021] In one embodiment of the present invention, the N-end driving unit further includes: a second inverter; the second inverter is used to receive and drive the to-be-driven signal, and the output end of the second inverter is connected to the gate of the NMOS tube.

[0022] To achieve the above-mentioned object and other related objects, the present invention provides a chip on the other hand, including: the driving output circuit based on series termination matching.

[0023] To achieve the above-mentioned objectives and other related objectives, the last aspect of the present invention provides a driving output method, which is applied to the driving output circuit based on series termination matching; the driving output method includes: inputting an external signal to be driven into the driving output circuit based on series termination matching for driving output; during the driving output of the signal to be driven, when an electrostatic voltage exists between the output port of the driving output circuit and the positive pole of the power supply or the ground, turning on the first discharge path, the second discharge path and the power clamp protection circuit to perform electrostatic protection.

[0024] As described above, the drive output circuit, chip, and drive output method based on series termination matching described in the present invention have the following beneficial effects:

[0025] The present invention improves the electrostatic protection structure of the existing series-terminated matching output driver by adding a second-level protection diode on the basis of the original electrostatic protection structure. The second-level protection diode is connected in series with the termination resistor existing in the original series-terminated matching output driver circuit to form a new electrostatic discharge path. In this way, the withstand voltage of the protected device is effectively reduced by voltage division, thereby achieving the purpose of improving the electrostatic protection capability. On the other hand, compared with the existing technology, on the basis of achieving the same electrostatic protection capability, the present invention can reduce the size requirements for the original first-level protection device (i.e., a pair of diodes), and can achieve a smaller capacitive load, thereby improving the signal transmission speed and reducing power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 FIG. 1 is a structural schematic diagram of a driver output circuit based on series termination matching in one embodiment of the present invention.

[0027] Figure 2 FIG. 1 is a circuit structure diagram of a driver output circuit based on series termination matching in one embodiment of the present invention.

[0028] Figure 3 FIG. 1 is a circuit diagram showing a driving output circuit based on series termination matching in one embodiment of the present invention.

[0029] Figure 4 FIG. 1 is a schematic structural diagram of a chip according to an embodiment of the present invention.

[0030] Figure 5 FIG. 1 is a flow chart showing the principle of a driving output method according to an embodiment of the present invention.

[0031] Component number description

[0032] 1 Driver output circuit based on series termination matching

[0033] 11 Signal drive output module

[0034] 12. First electrostatic current discharge module

[0035] 13. Second electrostatic current discharge module

[0036] 14 Power clamp protection module

[0037] Steps S11-S12 DETAILED DESCRIPTION

[0038] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0039] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0040] The drive output circuit, chip and drive output method based on series termination matching described in the present invention provide different discharge paths, effectively reduce the withstand voltage of the protected device through voltage division, and improve the electrostatic protection capability.

[0041] The following will be combined Figures 1 to 5 The principles and implementation methods of a drive output circuit, chip and drive output method based on series termination matching in this embodiment are described in detail so that those skilled in the art can understand the drive output circuit, chip and drive output method based on series termination matching in this embodiment without creative work.

[0042] See also Figure 1 , which shows a structural principle diagram of a driving output circuit based on series termination matching in one embodiment of the present invention. Figure 1 As shown, the external signal to be driven is input into the driving output circuit based on series termination matching for driving output to form an output signal; the driving output circuit based on series termination matching includes: a signal driving output module 11, a first electrostatic current discharge module 12, a second electrostatic current discharge module 13 and a power clamp protection module 14.

[0043] The signal driving output module 11 is used to drive and output the signal to be driven; the signal driving output module 11 includes a terminating resistor.

[0044] The first electrostatic current discharge module 12 is used to provide a first discharge path for the electrostatic current generated on the signal drive output module.

[0045] The second electrostatic current discharge module 13 is connected in series with the terminating resistor to provide a second discharge path for the electrostatic current.

[0046] The power clamping protection module 14 is respectively connected to the signal drive output module 11, the first electrostatic current discharge module 12 and the second electrostatic current discharge module 13, and is used to connect the first discharge path and the second discharge path when the power supply voltage of the signal drive output module exceeds the clamping voltage, so as to provide electrostatic protection for the signal drive output module.

[0047] It should be noted that the power clamp protection module described in the present invention is any circuit or device capable of monitoring using the clamping principle in the prior art, and the present invention is not limited thereto. Prior to clamping, the voltage monitored in the present invention may be a direct voltage value, or it may be a voltage-converted measurement of the current or other electrical signal state changes in the circuit, and the present invention is not limited thereto.

[0048] It should be noted that the present invention does not limit the number of the first electrostatic current discharge module and the second electrostatic current discharge module. The drive output circuit based on series termination matching may include one first electrostatic current discharge module and one second electrostatic current discharge module, or it may be a combination of any number of more than one first electrostatic current discharge module and second electrostatic current discharge module. The number of the first electrostatic current discharge module and the second electrostatic current discharge module may be the same or different.

[0049] See also Figure 2 , which shows a circuit structure diagram of a drive output circuit based on series termination matching in one embodiment of the present invention. Figure 2 As shown, the specific circuits and connection relationships of the signal driving output module 11, the first electrostatic current discharge module 12, the second electrostatic current discharge module 13 and the power clamp protection module 14 are presented.

[0050] In one embodiment of the present invention, the first electrostatic current discharge module 12 includes a first P-terminal protection unit and a first N-terminal protection unit.

[0051] One end of the first P-end protection unit is connected to the positive pole of the power supply, and the other end is connected to one end of the first N-end protection unit; the other end of the first N-end protection unit is connected to the ground.

[0052] Specifically, the first P-end protection unit is a first P-end protection diode PD1, and the first N-end protection unit is a first N-end protection diode ND1; the cathode of the first P-end protection diode PD1 is connected to the positive power supply VDD, and the anode is connected to the cathode of the first N-end protection diode ND1; the anode of the first N-end protection diode ND1 is connected to the ground VSS.

[0053] Among them, the connection point of the first P-terminal protection diode PD1 and the first N-terminal protection diode ND1 is the output port of the drive output circuit; the first P-terminal protection diode PD1 is used to be turned on when a forward electrostatic voltage is generated between the output port and VDD, providing a first discharge path for the electrostatic current; the first N-terminal protection diode ND1 is used to be turned on when a forward electrostatic voltage is generated between VSS and the output port, providing a first discharge path for the electrostatic current.

[0054] In one embodiment of the present invention, the second electrostatic current discharge module 13 includes a second P-terminal protection unit and a second N-terminal protection unit.

[0055] One end of the second P-end protection unit is connected to the positive power supply VDD, and the other end is connected to the signal drive output module; one end of the second N-end protection unit is connected to the signal drive output module, and the other end is connected to the ground VSS.

[0056] Specifically, the second P-terminal protection unit includes a second P-terminal protection diode PD2, and the second N-terminal protection unit includes a second N-terminal protection diode ND2.

[0057] The cathode of the second P-terminal protection diode PD2 is connected to the positive electrode of the power supply VDD, and the anode is connected to the signal drive output module; the second P-terminal protection diode PD2 is used to be turned on when a forward electrostatic voltage is generated between the output port and VDD, and the termination resistor R n Together, a second discharge path is provided for the electrostatic current.

[0058] The anode of the second N-terminal protection diode ND2 is connected to the ground VSS, and the cathode is connected to the signal drive output module; the second N-terminal protection diode ND2 is used to be turned on when a forward electrostatic voltage is generated between VSS and the output port, and the termination resistor R p Together, a second discharge path is provided for the electrostatic current.

[0059] In one embodiment of the present invention, the signal drive output module includes a P-end drive unit and an N-end drive unit; the connection point between the P-end drive unit and the N-end drive unit is the output port of the drive output circuit; the P-end drive unit and the N-end drive unit are used to perform voltage division driving on the signal to be driven.

[0060] An anode of the second P-end protection diode PD2 is connected to the N-end driving unit; and a cathode of the second N-end protection diode ND2 is connected to the P-end driving unit.

[0061] In one embodiment of the present invention, a voltage range driven by the P-end driving unit is greater than a voltage range driven by the N-end driving unit.

[0062] Specifically, the P-end driving unit includes a PMOS transistor M p and the P-terminal resistor R p ; Wherein, the P-terminal resistor R p is the first termination resistor. p The source is connected to the positive power supply VDD, the gate is used to receive the drive signal, the drain is connected to the P-terminal resistor R p The P-terminal resistor R p The other end is connected to the N-end driving unit.

[0063] Furthermore, the P-terminal resistor R p One end of the P-terminal resistor R p It is used to form the second discharge path with the conductive second N-terminal protection diode ND2 when a forward electrostatic voltage is generated between VSS and the output port.

[0064] Furthermore, the P-end driving unit further includes: a first inverter G1; the first inverter G1 is used to receive and drive the to-be-driven signal, and the output end of the first inverter G1 is connected to the PMOS transistor M p Gate connection.

[0065] In one embodiment of the present invention, the N-terminal driving unit includes: an NMOS transistor M n and N-terminal resistor R n ; Wherein, the N-terminal resistor is the second terminal resistor R n .

[0066] The NMOS tube M n The source is connected to the ground VSS, the gate is used to receive the drive signal, the drain is connected to the N-terminal resistor R n One end of the N-terminal resistor R nThe other end is connected to the P-end driving unit.

[0067] In one embodiment of the present invention, the NMOS transistor M n The process uses thin gate devices. Similarly, the PMOS tube M p The process also uses thin-gate devices.

[0068] Furthermore, the N-terminal resistor R n One end of the N-terminal resistor R n It is used to form the second discharge path with the conductive second P-end protection diode PD2 when a forward electrostatic voltage is generated between the output port and VDD.

[0069] Furthermore, the N-end driving unit further includes: a second inverter G2; the second inverter G2 is used to receive and drive the to-be-driven signal, and the output end of the second inverter G2 is connected to the NMOS transistor M n Gate connection.

[0070] See also Figure 3 , which is a circuit diagram of a driving output circuit based on series termination matching in one embodiment of the present invention. Figure 3 As shown, it presents Figure 2 Circuits with the same circuit but different placement of components (mainly termination resistors). Figure 3 The path indicated by the dotted arrow is the discharge path of the second electrostatic current discharge module when a positive electrostatic voltage is applied between the output port and the ground VSS. The following is a detailed explanation of the electrostatic current discharge principle:

[0071] When the outside world applies a positive electrostatic voltage Va between the output port and VSS (for example, the output port is set to a positive voltage higher than VDD and can cause VDD to increase, and VSS is 0V), the value of the power supply voltage VDD is between the output port and VSS, which is a voltage between VDD-Va. At this time, the output port voltage is Va, VSS is 0V, and PD1 and PD2 are turned on due to the positive voltage difference. On the one hand, the current flows through the forward-conducting PD1 and first flows to the power supply VDD. Then the power clamp protection module detects the increase in the power supply voltage VDD and turns on its protection circuit, so that the electrostatic current of the output port is discharged to the ground VSS through the power clamp protection module; on the other hand, the current flows through the second termination resistor R n The current flowing to the forward-conducting PD2 first flows to the power supply VDD, and then the power clamp protection module detects the increase of the power supply voltage VDD and turns on its protection circuit, so that the electrostatic current of the output port is discharged to the ground VSS through the power clamp protection module.

[0072] When a positive electrostatic voltage Vb is applied from the positive power supply voltage VDD to the output port (for example, setting VDD to a higher positive voltage than the current VDD and the output port voltage to 0V), the value of VSS is between the positive power supply voltage and the output port. At this point, VSS is a raised positive voltage between 0 and Vb, and the output port voltage is 0V. ND1 and ND2 are conducting due to the positive voltage difference. On the one hand, the power clamp protection module detects the increase in power supply voltage VDD and activates its protection circuit. The electrostatic current from VDD is discharged through the power clamp protection module to VSS, and then from VSS to ND1, reaching the output port, completing the electrostatic current discharge. On the other hand, the power clamp protection module detects the increase in power supply voltage VDD and activates its protection circuit. The electrostatic current from VDD is discharged through the power clamp protection module to VSS, and then from VSS to ND2 and Rp, reaching the output port, completing the electrostatic current discharge.

[0073] The beneficial effects of the present invention are described by taking the case where a forward electrostatic voltage Va is applied between the output port and VSS as an example.

[0074] On the one hand, the path from the output port to the power supply VDD is increased by R n The path formed by the forward conduction of PD2 in series is in parallel with the forward conduction of PD1, which together discharges the electrostatic current from the port to the power supply. Therefore, the most vulnerable device is the NMOS device M n The drain and gate voltage difference becomes the sum of the voltage difference of PD2 forward conduction and the voltage difference of the power clamp protection circuit, such as Figure 3 As shown by the dotted arrow, let the resistor R n The impedance of the path formed by the forward conduction in series with PD2 is much greater than that of the first-stage P-type diode. The formula can be obtained as follows: The drain and gate voltage difference V gd =V pdio2 +V clamp =0.7V+I ESD *R pdio *R pdio2 / (R n +R pdio2 )+I ESD *R clamp , where V gd is the drain and gate voltage difference, V pdio2 is the voltage difference of PD2 when it is forward-conducting, V clamp is the voltage difference of the power clamp protection circuit, 0.7V is the forward turn-on voltage of the diode, I ESD is the electrostatic current, R pdio is the on-resistance of PD1, R pdio2 is the on-resistance of PD2, R clampIt can be seen that the present invention divides the forward conduction voltage of PD1, and the voltage division coefficient is R pdio2 / (R n +R pdio2 ).

[0075] Considering the HBM 2KV electrostatic test conditions, the maximum current is 1.3A. Since the power clamp protection circuit has not changed, the voltage difference remains less than or equal to 1V. n The resistance value is usually in the order of tens of ohms. Taking 50 ohms as an example, assuming that the impedance of PD2 is also 50 ohms, the above voltage division coefficient is 0.5. Therefore, when the impedance of PD1 is still 1 ohm, the actual voltage division of PD2 is: 1.3A*1ohm*0.5=0.65V. Substituting 0.65V into the above formula, the final result is Vgd=0.7V+0.65V+1V=2.35V, which can meet the condition that the gate oxide layer breakdown voltage of thin-gate devices is usually less than or equal to 3V. Compared with using only PD1 alone, only 1 / 50 of the size of PD1 needs to be increased, which is a very small cost. If the existing circuit is used, to reduce Vgd to 2.35V, the size of PD1 needs to be doubled. Therefore, the circuit structure of the present invention has obvious advantages.

[0076] On the other hand, if the proposed structure is to meet the Vgd = 3.0V requirement and the voltage divider coefficient remains unchanged at 0.5, the size of the first-stage P-type diode can be reduced to only half that of the original implementation. Therefore, while maintaining the same ESD protection capability, the proposed structure can significantly reduce the size of the original first-stage diode, thereby reducing the capacitive load, ultimately achieving the goals of increasing signal transmission speed and reducing power consumption.

[0077] The beneficial effect is similar to that produced when a positive electrostatic voltage Vb is applied between the positive power supply VDD and the output port. The path formed by the forward-conducting series connection of the resistor Rp and ND2 can help reduce the PMOS device M p The drain voltage will not be described in detail here.

[0078] See also Figure 4 , which is a schematic diagram showing the structure of a chip according to an embodiment of the present invention. Figure 4 As shown, the chip of the present invention includes: the driving output circuit based on series termination matching, and the external driving signal is input into the driving output circuit based on series termination matching for driving output.

[0079] The drive output circuit based on series termination matching includes: a signal drive output module, used to drive and output the signal to be driven; the signal drive output module includes a termination resistor; a first electrostatic current discharge module, used to provide a first discharge path for the electrostatic current generated on the signal drive output module; a second electrostatic current discharge module, connected in series with the termination resistor, used to provide a second discharge path for the electrostatic current; a power clamp protection module, respectively connected to the first electrostatic current discharge module and the second electrostatic current discharge module, used to turn on the first discharge path and the second discharge path when the power supply voltage of the signal drive output module exceeds the clamping voltage, so as to provide electrostatic protection for the signal drive output module.

[0080] See also Figure 5 , which is a flow chart showing the principle of the drive output method of the present invention in one embodiment. Figure 5 As shown, the driving output method is applied to the driving output circuit based on series termination matching described in the present invention; specifically, it includes the following steps:

[0081] S11 , inputting an external signal to be driven into the driving output circuit based on series termination matching for driving output.

[0082] S12, during the process of driving output of the drive signal, when an electrostatic voltage exists between the output port of the drive output circuit and the positive pole of the power supply or the ground, turning on the first discharge path, the second discharge path and the power clamp protection circuit to perform electrostatic protection.

[0083] The protection scope of the driving output method described in the present invention is not limited to the execution order of the steps listed in this embodiment. All solutions implemented by adding, reducing, or replacing steps in the prior art based on the principles of the present invention are included in the protection scope of the present invention.

[0084] The principle of the driving output method described in the present invention corresponds one-to-one to the driving output circuit based on series termination matching. The driving output circuit based on series termination matching described in the present invention can implement the driving output method described in the present invention. However, the implementation device of the driving output method described in the present invention includes but is not limited to the structure of the driving output circuit based on series termination matching listed in this embodiment. All structural deformations and replacements of the prior art made according to the principles of the present invention are included in the protection scope of the present invention.

[0085] In summary, the drive output circuit, chip and drive output method based on series termination matching described in the present invention improve the electrostatic protection structure of the existing series termination matching output driver, by adding a second-level protection diode on the basis of the original electrostatic protection structure, and the second-level protection diode is connected in series with the termination resistor existing in the original series termination matching output driver circuit to form a new electrostatic discharge path, thereby effectively reducing the withstand voltage of the protected device through voltage division, thereby achieving the purpose of improving the electrostatic protection capability. On the other hand, compared with the prior art, on the basis of achieving the same electrostatic protection capability, the present invention can reduce the size requirements of the original first-level protection device (i.e., a pair of diodes), and can achieve a smaller capacitive load, thereby increasing the signal transmission speed and reducing power consumption. The present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0086] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A driving output circuit based on series termination matching, characterized in that: The external drive signal is input into the drive output circuit based on series termination matching for drive output; The driving output circuit based on series termination matching includes: A signal drive output module, configured to drive and output the signal to be driven; the signal drive output module includes a termination resistor; A first electrostatic current discharge module, configured to provide a first discharge path for the electrostatic current generated on the signal drive output module; a second electrostatic current discharge module, connected in series with the terminating resistor, for providing a second discharge path for the electrostatic current; a power clamp protection module, connected to the first electrostatic current discharge module and the second electrostatic current discharge module, respectively, for conducting the first discharge path and the second discharge path when the power supply voltage of the signal drive output module exceeds the clamping voltage, thereby providing electrostatic protection for the signal drive output module; Wherein, the termination resistor includes a P-terminal resistor and an N-terminal resistor connected in series, and the connection point of the P-terminal resistor and the N-terminal resistor is connected to the output port of the drive output circuit; the second electrostatic current discharge module includes a second P-terminal protection unit and a second N-terminal protection unit, one end of the second P-terminal protection unit is connected to the positive pole of the power supply, and the other end is connected to the output port via the N-terminal resistor, and one end of the second N-terminal protection unit is connected to the ground, and the other end is connected to the output port via the P-terminal resistor; The N-terminal resistor and the second P-terminal protection unit form the second discharge path when a positive electrostatic voltage is generated between the output port and the positive pole of the power supply or between the output port and the ground; the P-terminal resistor and the second N-terminal protection unit form the second discharge path when a positive electrostatic voltage is generated between the positive pole of the power supply and the output port or between the ground and the output port.

2. The driving output circuit based on series termination matching according to claim 1, characterized in that: The first electrostatic current discharge module includes a first P-terminal protection unit and a first N-terminal protection unit; One end of the first P-end protection unit is connected to the positive electrode of the power supply, and the other end is connected to one end of the first N-end protection unit; The other end of the first N-end protection unit is connected to the ground.

3. The driving output circuit based on series termination matching according to claim 2, characterized in that: The first P-terminal protection unit is a first P-terminal protection diode, and the first N-terminal protection unit is a first N-terminal protection diode; The cathode of the first P-terminal protection diode is connected to the positive electrode of the power supply, and the anode is connected to the cathode of the first N-terminal protection diode; the anode of the first N-terminal protection diode is connected to the ground; Among them, the connection point of the first P-terminal protection diode and the first N-terminal protection diode is the output port of the drive output circuit; the first P-terminal protection diode is used to be turned on when a forward electrostatic voltage is generated between the output port and the positive pole of the power supply, thereby providing a first discharge path for the electrostatic current; the first N-terminal protection diode is used to be turned on when a forward electrostatic voltage is generated between the ground and the output port, thereby providing a first discharge path for the electrostatic current.

4. The driving output circuit based on series termination matching according to claim 1, characterized in that: The second P-terminal protection unit includes a second P-terminal protection diode, and the second N-terminal protection unit includes a second N-terminal protection diode; The cathode of the second P-terminal protection diode is connected to the positive electrode of the power supply, and the anode is connected to the N-terminal resistor; the second P-terminal protection diode is configured to conduct when a forward electrostatic voltage is generated between the output port and the positive electrode of the power supply, thereby providing a second discharge path for the electrostatic current; The anode of the second N-terminal protection diode is connected to the ground, and the cathode is connected to the P-terminal resistor; the second N-terminal protection diode is used to be turned on when a forward electrostatic voltage is generated between the ground and the output port, providing a second discharge path for the electrostatic current.

5. The driving output circuit based on series termination matching according to claim 4, characterized in that: The signal drive output module includes a P-end drive unit and an N-end drive unit; the connection point of the P-end drive unit and the N-end drive unit is connected to the output port of the drive output circuit; The P-end driving unit and the N-end driving unit are used to perform voltage division driving on the signal to be driven; The anode of the second P-terminal protection diode is connected to the N-terminal driving unit; The cathode of the second N-terminal protection diode is connected to the P-terminal driving unit.

6. The driving output circuit based on series termination matching according to claim 5, characterized in that: The voltage range driven by the P-end driving unit is greater than the voltage range driven by the N-end driving unit.

7. The driving output circuit based on series termination matching according to claim 5, characterized in that: The P-terminal driving unit includes a PMOS tube and the P-terminal resistor; The source of the PMOS tube is connected to the positive electrode of the power supply, the gate is used to receive the drive signal, and the drain is connected to one end of the P-terminal resistor; the other end of the P-terminal resistor is connected to the N-terminal driving unit.

8. The driving output circuit based on series termination matching according to claim 7, characterized in that: The P-end driving unit further includes: a first inverter; The first inverter is used to receive and drive the to-be-driven signal, and the output end of the first inverter is connected to the gate of the PMOS tube.

9. The driving output circuit based on series termination matching according to claim 7, characterized in that: The PMOS tube process adopts thin gate devices.

10. The driving output circuit based on series termination matching according to claim 5, characterized in that: The N-terminal driving unit includes: an NMOS tube and the N-terminal resistor; The source of the NMOS tube is connected to the ground, the gate is used to receive the drive signal, the drain is connected to one end of the N-terminal resistor, and the other end of the N-terminal resistor is connected to the P-terminal driving unit.

11. The driving output circuit based on series termination matching according to claim 10, characterized in that: The NMOS tube process adopts thin gate devices.

12. The driving output circuit based on series termination matching according to claim 10, characterized in that: The N-end driving unit further includes: a second inverter; The second inverter is used to receive and drive the to-be-driven signal, and the output end of the second inverter is connected to the gate of the NMOS transistor.

13. A chip, characterized in that: include: A driver output circuit based on series termination matching as claimed in any one of claims 1 to 12.

14. A driving output method, characterized in that: Applicable to the driving output circuit based on series termination matching as claimed in any one of claims 1 to 12; The driving output method includes: Inputting an external drive signal to be driven into the drive output circuit based on series termination matching for drive output; During the process of driving output of the drive signal, when electrostatic voltage exists between the output port of the drive output circuit and the positive pole of the power supply or the ground, the first discharge path, the second discharge path and the power clamp protection circuit are turned on to perform electrostatic protection.

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