CN115085169A

CN115085169A - External power supply processing circuit

Info

Publication number: CN115085169A
Application number: CN202110263703.3A
Authority: CN
Inventors: 吴红红; 王富中
Original assignee: Galaxycore Shanghai Ltd Corp
Current assignee: Galaxycore Shanghai Ltd Corp
Priority date: 2021-03-10
Filing date: 2021-03-10
Publication date: 2022-09-20

Abstract

The invention provides an external power supply processing circuit, which is characterized in that a voltage clamping module is arranged between an external power supply and an internal module, the voltage clamping module comprises a voltage reduction unit and a switch unit which are connected in parallel, when the external power supply is at normal working voltage, the switch unit is switched on and has smaller voltage drop, the voltage of the internal module is normal, when the external power supply is at abnormal surge voltage, the switch unit is switched off, the voltage reduction unit is switched on and forms large voltage drop, so that the voltage of the internal module is far lower than the voltage of the external power supply, the normal operation of the internal module is ensured, and the reliability of devices is improved. In addition, a current generation unit can be further arranged between the voltage clamping module and the internal module or among the internal modules, and a large current can be flexibly provided for the voltage reduction unit so as to form a large voltage reduction, so that a better voltage reduction effect can be obtained.

Description

External power supply processing circuit

Technical Field

The invention relates to an external power supply processing circuit.

Background

Surges are also called surges and as the name suggests are transient overvoltages that exceed normal operating voltages. In essence, a surge is a sharp pulse that occurs in only a few millionths of a second. Surges are prevalent in power distribution systems, i.e., the surges are ubiquitous. The effects it may cause may be: the voltage of the system fluctuates, under the normal working condition, the machine equipment can automatically stop or start, the computer control system is reset without reason, the motor is replaced or reset frequently, and the service life of the electrical equipment is shortened due to faults, reset or voltage problems.

During the operation of the conventional integrated circuit chip, the chip may also suffer from surge, that is, an external power supply of the chip has transient overvoltage exceeding the normal operating voltage, and the transient overvoltage can often make the amplitude of the voltage exceed more than twice of the normal value within microsecond time, which may be caused by lightning, poor grounding, electrostatic discharge (ESD), short circuit, power switching, and the like. Such severe voltage pulses in microsecond time may cause many adverse effects to the chip, such as damage to internal devices of the chip, loss of internal data, and the like, and thus, the performance of the chip may be degraded.

For example, when the display driver chip encounters an instantaneous surge of the external power supply voltage during the operation process, the voltage of a part of internal modules also rises along with the rise of the external power supply voltage, which may cause some internal circuits to have abnormal functions, thereby causing display problems.

Therefore, the chip needs to be reasonably protected correspondingly, so that the chip can work normally when the power supply of the chip is subjected to transient overvoltage exceeding the normal working voltage.

Disclosure of Invention

The invention aims to provide an external power supply processing circuit, which can reduce the adverse effect caused by the instantaneous surge of the voltage of an external power supply, ensure the normal operation of internal modules and improve the reliability of devices.

Based on the above consideration, the present invention provides an external power supply processing circuit, including: the voltage clamping module is arranged between the external power supply and the internal module; the voltage clamping module comprises a voltage reduction unit and a switch unit which are connected in parallel, wherein the switch unit is switched on when the external power supply is at a normal working voltage and switched off when the external power supply is at an abnormal surge voltage.

Preferably, the switch unit is an NMOS transistor, and a gate voltage of the NMOS transistor is greater than a normal operating voltage of the external power supply and less than an abnormal surge voltage of the external power supply.

Preferably, the switch unit is a PMOS transistor, a triode or a transmission gate.

Preferably, the voltage reduction unit is a resistor, an MOS transistor, a diode or a triode.

Preferably, the external power supply processing circuit further includes: a current generating unit connected between the voltage clamping module and an internal module or located within the internal module.

Preferably, the current generating unit includes a single or cascaded diode, a MOS transistor, or a triode.

Preferably, the threshold voltage of the current generating unit is greater than the normal operating voltage of the external power supply and less than the abnormal surge voltage of the external power supply, so that the current generated by the current generating unit is small when the voltage of the external power supply is normal, and the current generated by the current generating unit is large when the voltage of the external power supply is abnormally surge.

According to the external power supply processing circuit, the voltage clamping module is arranged between the external power supply and the internal module and comprises the voltage reduction unit and the switch unit which are connected in parallel, when the external power supply is at a normal working voltage, the switch unit is conducted and has a small voltage drop, the voltage of the internal module is normal, when the external power supply is at an abnormal surge voltage, the switch unit is disconnected, the voltage reduction unit is conducted and forms a large voltage drop, so that the voltage of the internal module is far lower than the voltage of the external power supply, the normal operation of the internal module is ensured, and the reliability of devices is improved. In addition, the current generation unit can be further arranged between the voltage clamping module and the internal module or in the internal module, so that larger current is flexibly provided for the voltage reduction unit to form larger voltage reduction, and a better voltage reduction effect is obtained.

Drawings

Other features, objects and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments thereof, which is to be read in connection with the accompanying drawings.

Fig. 1 is a schematic structural diagram of an external power supply processing circuit according to the present invention.

In the drawings, like or similar reference numbers indicate like or similar devices (modules) or steps throughout the different views.

Detailed Description

In order to solve the problems in the prior art, the invention provides an external power supply processing circuit, wherein a voltage clamping module is arranged between an external power supply and an internal module, the voltage clamping module comprises a voltage reduction unit and a switch unit which are connected in parallel, when the external power supply is at a normal working voltage, the switch unit is switched on and has a smaller voltage drop, the voltage of the internal module is normal, when the external power supply is at an abnormal surge voltage, the switch unit is switched off, the voltage reduction unit is switched on and forms a large voltage drop, so that the voltage of the internal module is far lower than the voltage of the external power supply, the normal operation of the internal module is ensured, and the reliability of devices is improved. In addition, the current generation unit can be further arranged between the voltage clamping module and the internal module or in the internal module, so that larger current is flexibly provided for the voltage reduction unit to form larger voltage reduction, and a better voltage reduction effect is obtained.

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof. The accompanying drawings illustrate, by way of example, specific embodiments in which the invention may be practiced. The illustrated embodiments are not intended to be exhaustive of all embodiments according to the invention. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

FIG. 1 illustrates a preferred embodiment of the externally powered processing circuitry of the present invention, wherein: an external power supply (e.g., VDDI) 1, an internal module 2, and usually, the internal module 2 is mostly a low power consumption module, and a voltage clamping module 3 is disposed between the external power supply 1 and the internal module 2, where the voltage clamping module 3 includes a voltage dropping unit 4 and a switch unit 5 connected in parallel.

In the embodiment shown in fig. 1, the voltage-reducing unit 4 is a resistor, and the resistance R of the resistor 4 is much larger than the on-resistance of the switching unit 5 in the linear region; in other embodiments not shown, the voltage reducing unit 4 may also be implemented by other manners such as a MOS transistor, a diode, or a triode, and specifically, a suitable device may be selected as the voltage reducing unit according to different application environments.

In the embodiment shown in fig. 1, the switching unit 5 is an NMOS transistor; in other embodiments not shown, the switch unit 5 may also be implemented by other devices with switching function, such as PMOS transistor, triode or transmission gate.

In the external power supply processing circuit of the present invention, the gate voltage V0 (V0 may be AVDD or a voltage generated in the AVDD power domain) of the NMOS transistor 5 is connected to the gate voltage V0, which is greater than the normal operating voltage V1 of the external power supply VDDI and less than the abnormal surge voltage V2 of the external power supply VDDI (i.e. V1< V0< V2).

When the external power supply VDDI is at the normal operating voltage V1, the gate voltage V0 of the NMOS transistor 5 is greater than V1, the NMOS transistor 5 is turned on, the resistance value of the on-resistance is much smaller than the resistance value R of the resistance 4, the current of the voltage clamp module basically flows through the NMOS transistor 5 and generates a small voltage drop, and the voltage VDDI _ int of the internal module 2 is at the normal operating range.

When the external power supply VDDI is at the abnormal surge voltage V2, the gate voltage V0 of the NMOS transistor 5 is less than V2, the NMOS transistor 5 is turned off, the module current flows through the resistor 4 completely, and a large voltage drop is formed at two ends of the resistor 4, so that the voltage VDDI _ int of the internal module 2 is far lower than the external power supply voltage V2, that is, the voltage VDDI _ int of the internal module 2 does not surge with the surge of the external power supply voltage, thereby reducing the adverse effect caused by the instantaneous surge of the external power supply voltage, ensuring the normal operation of the internal module, and improving the reliability of the device.

Preferably, the external power supply processing circuit of the present invention may further include a current generating unit 6, in the embodiment shown in fig. 1, the current generating unit 6 is connected between the voltage clamping module 3 and the internal module 2, and in other embodiments not shown, the current generating unit 6 may also be located in the internal module 2, which may be selected according to different applications of the internal module 2.

In the embodiment shown in fig. 1, the current generating unit 6 includes cascaded diodes, and in other embodiments not shown, the current generating unit 6 may also be a single diode, a MOS transistor or a transistor, or cascaded MOS transistors or transistors, where the number of the cascaded diodes depends on the specific application.

The threshold voltage of the current generating unit 6 is greater than the normal operating voltage V1 of the external power supply VDDI and less than the abnormal surge voltage V2 of the external power supply VDDI, when the external power supply VDDI is at the normal operating voltage V1, the current of the current generating unit is smaller, the current flowing through the voltage clamping module is correspondingly smaller, when the external power supply VDDI is at the abnormal surge voltage V2, the current of the current generating unit is increased, the current flowing through the voltage clamping module is correspondingly increased, and then larger current can be flexibly provided for the voltage reducing unit as required, so that larger voltage drop is formed, a better voltage reducing effect is obtained, and the normal operation of the internal module is ensured.

In summary, in the external power supply processing circuit of the present invention, the voltage clamping module is disposed between the external power supply and the internal module, and the voltage clamping module includes the voltage reduction unit and the switch unit connected in parallel, when the external power supply is at the normal operating voltage, the switch unit is turned on and has a small voltage drop, the voltage of the internal module is normal, and when the external power supply is at the abnormal surge voltage, the switch unit is turned off and the voltage reduction unit is turned on and forms a large voltage drop, so that the voltage of the internal module is far lower than the voltage of the external power supply, the normal operation of the internal module is ensured, and the reliability of the device is improved. In addition, a current generation unit can be further arranged between the voltage clamping module and the internal module or among the internal modules, and a large current can be flexibly provided for the voltage reduction unit so as to form a large voltage reduction, so that a better voltage reduction effect can be obtained.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. It will furthermore be evident that the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. Several elements recited in the apparatus claims may also be embodied by one element. The terms first, second, etc. are used to denote names, but not any particular order.

Claims

1. An externally powered processing circuit, comprising:

the voltage clamping module is arranged between the external power supply and the internal module;

the voltage clamping module comprises a voltage reduction unit and a switch unit which are connected in parallel, wherein the switch unit is switched on when the external power supply is at normal working voltage, and is switched off when the external power supply is at abnormal surge voltage.

2. The external power supply processing circuit of claim 1, wherein the switching unit is an NMOS transistor, and a gate voltage of the NMOS transistor is greater than a normal operating voltage of the external power supply and less than an abnormal surge voltage of the external power supply.

3. The external power supply processing circuit of claim 1, wherein the switch unit is a PMOS transistor, a triode, or a transmission gate.

4. The externally-supplied power processing circuit of claim 1, wherein the voltage dropping unit is a resistor, a MOS transistor, a diode or a triode.

5. The externally-supplied power processing circuit of claim 1, further comprising: a current generating unit connected between the voltage clamping module and an internal module or located within the internal module.

6. The externally-supplied power processing circuit of claim 4, wherein the current generating unit comprises a single or cascaded diode, MOS tube, or triode.

7. The external power supply processing circuit of claim 4, wherein the threshold voltage of the current generating unit is greater than the normal operating voltage of the external power supply and less than the abnormal surge voltage of the external power supply, such that the current of the current generating unit is low when the external power supply voltage is normal and the current of the current generating unit is high when the external power supply voltage is abnormal.