TWI493821B - Operational circuit having over-current protection mechanism - Google Patents

Description

Operation circuit with overcurrent protection mechanism

The invention relates to an overcurrent protection technology, and in particular to an arithmetic circuit with an overcurrent protection mechanism.

Electronic products are an integral part of modern life. Mobile phones, computers, automobiles and even home appliances are often equipped with processors with computing power. However, due to the miniaturization of electronic products, although they have the advantage of small size, they are also prone to failure due to physical or electrical damage. Among them, in the operation of the wafer or circuit, if a large current is generated due to improper operation, it may cause the wafer or circuit to overheat and cause burnout. Therefore, the chip or circuit is often configured with an overcurrent protection circuit to ensure that the overcurrent protection mechanism is activated to avoid damage when the current exceeds the rated value.

In the judgment of whether the overcurrent protection mechanism is activated, it is often required to perform comparison with the reference current. However, in the prior art, a fixed reference current is used as a reference. In electronic components that are highly susceptible to environmental influences, such designs will not be able to elastically activate overcurrent protection mechanisms, and will not have more efficient protection.

Therefore, how to design a new arithmetic circuit with overcurrent protection mechanism to solve the above problems is an urgent problem to be solved in the industry.

Therefore, an aspect of the present invention provides an arithmetic circuit with an overcurrent protection mechanism, including: a first circuit level, a second circuit level, a protection circuit, and a first dynamic reference current generation module. The first circuit stage includes a first input end for receiving the input signal and a second input end for receiving the output signal, to generate a first control signal according to the input signal and the output signal, and a second control at the second output end Signal. The second circuit stage is coupled to the first circuit stage to generate an output signal according to the first driving current and the second driving current, wherein the first driving current is controlled by the first control signal, and the second driving current is controlled by the second control signal produce. The protection circuit is coupled between the first circuit stage and the second circuit stage to detect the first driving current to selectively adjust the first control signal, wherein the protection circuit comprises: a first switching control unit and a first adjusting unit. The first switching control unit is configured to compare the first detection current generated by the first driving current and the first dynamic reference current to generate a first switching control signal. The first adjustment unit is coupled to the first supply voltage, and the other end is coupled to the first output end of the first circuit stage, wherein the first adjustment unit is configured to the first control signal when the first switching control signal is at the enable level Make adjustments. The first dynamic reference current generating module generates a first dynamic reference current according to the voltage-variable current generated by the voltage-variable current generating circuit and the temperature-varying current generated by the temperature-varying current generating circuit.

According to an embodiment of the invention, the temperature-variable current is a negative temperature coefficient current, and the voltage-variable current is a positive voltage coefficient current, and the first dynamic reference current generating module is configured to subtract the temperature-varying current and the pressure-variable current to generate a first dynamic reference. Electricity flow.

According to another embodiment of the invention, the first drive current is a sourcing current of the second circuit stage.

According to still another embodiment of the present invention, the first driving current is a sinking current of the second circuit level.

According to still another embodiment of the present invention, the first adjusting unit adjusts the first control signal to decrease the first driving current when the first detecting current is greater than the first dynamic reference current.

According to a further embodiment of the invention, the second circuit stage comprises: a first drive element and a second drive element. The first driving component is coupled to the first output terminal to receive the first control signal and generate a first driving current. The second driving component is coupled to the second output terminal to receive the second control signal and generate a second driving current.

According to still another embodiment of the present invention, the first switching control unit includes: a first detecting component and a first current comparator. The first detecting component is coupled to the first output terminal to detect the first driving current and generate the first detecting current. The first current comparator is coupled to the first detecting component and the first dynamic reference current generating module to compare the first detecting current and the first dynamic reference current to generate a first switching control signal. The first adjusting unit includes a current source and a switching component, and the current source provides a control current to the first control signal when the switching component is enabled by the first switching control signal.

According to an embodiment of the invention, the protection circuit further includes: a second dynamic reference current generation module, a second switching control unit, and a second adjustment unit. The second dynamic reference current generating module provides the second dynamic reference power flow. The second switching control unit compares the second detection current generated by the second driving current and the second dynamic reference current to generate a second switching control signal. The second adjustment unit is coupled to the second supply voltage, and the other end is coupled to the second output end of the first circuit stage, wherein the second adjustment unit controls the second control signal when the second switching control signal is at the enable level Make adjustments.

According to another embodiment of the invention, the first circuit stage is an operational amplifier.

The invention has the advantages that the reference current value which can be dynamically adjusted with the operating environment of the system is provided by the temperature change and the voltage change current to provide a more flexible overcurrent protection mechanism, and the above purpose is easily achieved.

1‧‧‧Operating circuit

10‧‧‧First circuit level

12‧‧‧second circuit level

120‧‧‧First drive element

122‧‧‧Second drive element

14‧‧‧Protection circuit

140‧‧‧First switching control unit

141‧‧‧Second switching control unit

142‧‧‧First adjustment unit

143‧‧‧Second adjustment unit

144‧‧‧First detection component

145‧‧‧Second detection component

146‧‧‧First current comparator

147‧‧‧Second current comparator

16‧‧‧First Dynamic Reference Current Generation Module

20‧‧‧temperature change current generation circuit

22‧‧‧Pressure current generation circuit

24‧‧‧current mirror

30‧‧‧current source

32‧‧‧Switching components

Figure 1 is a circuit diagram of an arithmetic circuit in accordance with an embodiment of the present invention.

FIG. 2 is a circuit diagram of a first dynamic reference current generating module according to an embodiment of the invention.

Fig. 3 is a circuit diagram of an arithmetic circuit in an embodiment of the invention.

Fig. 4 is a circuit diagram of an arithmetic circuit in an embodiment of the invention.

Please refer to Figure 1. FIG. 1 is a circuit diagram of an arithmetic circuit 1 with an overcurrent protection mechanism according to an embodiment of the present invention. The operation circuit 1 includes a first circuit stage 10, a second circuit stage 12, a protection circuit 14, and a first dynamic reference current generation module 16.

In this embodiment, the first circuit stage 10 is an operational amplifier. The first input terminal In1, the second input terminal In2, the first output terminal Out1 and the second output terminal Out2 are included. The first input terminal In1 is configured to receive an input signal Vin, and the second input terminal In2 is configured to receive the output signal Vout of the operation circuit 1. The first circuit stage 10 generates a first control signal Vp and a second control signal Vn at the first output terminal Out1 and the second output terminal Out2 according to the input signal Vin and the output signal Vout.

The second circuit stage 12 is coupled to the first circuit stage 10. In the present embodiment, the second circuit stage 12 includes a first driving element 120 and a second driving element 122. The first driving component 120 is a P-type MOS transistor in this embodiment, and the second driving component 122 is an N-type MOS transistor in this embodiment. The source of the first driving component 120 is connected to the supply voltage VDD, the drain is connected to the output terminal O that generates the output signal Vout, and the gate is coupled to the first output terminal Out1, and receives the first control signal Vp, and generates The first drive current I1. The source of the second driving component 122 is connected to the ground potential GND, the drain is connected to the output terminal O which generates the output signal Vout, the gate is coupled to the second output terminal Out2, and the gate thereof receives the second control signal Vn, and A second drive current I2 is generated accordingly.

In the operational state, the first drive current I1 will be the source current of the second circuit stage 12 to provide current to the output terminal O. The second drive current I2 will be the current drawn by the second circuit stage 12 to draw current from the output terminal O.

The protection circuit 14 is coupled between the first circuit stage 10 and the second circuit stage 12 to detect the first driving current I1 and selectively adjust the first control signal Vp. The protection circuit 14 includes a first switching control unit 140 and a first adjusting unit 142.

The first switching control unit 140 includes a first detecting component 144 and a first current comparator 146. The first detecting component 144 is coupled to the first output terminal Out1 and detects the first driving current I1 to generate the first detecting current Io1. In one embodiment, the first detecting component 144 generates the first detecting current Io1 in the form of a current mirror. Therefore, according to the component size design of the first driving component 120, the first detecting current Io1 may be equivalent to the first driving current I1 or a multiple of the first driving current I1. The first current comparator 146 is further compared according to the first detection current Io1 and a first dynamic reference current Iref1 generated by the first dynamic reference current generation module 16 to generate a first switching control signal Vc1.

The first adjusting unit 142 can determine whether to activate the circuit protection mechanism according to the voltage level of the first switching control signal Vc1. In an embodiment, when the first detection current Io1 generated according to the first driving current I1 is smaller than the first dynamic reference current Iref1, the first switching control signal Vc1 of the low voltage level is generated to suppress The first adjustment unit 142. When the output end of the arithmetic circuit 1 is connected to the ground, the potential value of the output signal Vout is grounded, the first driving current I1 is increased, and the first detecting current Io1 is further greater than the first dynamic reference current Iref1. . The first switching control signal Vc1 will transition to a high voltage level to enable the first adjustment unit 142 to initiate an overcurrent protection mechanism. In the embodiment, the overcurrent protection mechanism adjusts the first control signal Vp to control the first driving component 120 when the first driving current I1 is excessively large by the enabling of the first adjusting unit 142, and reduces the first driving component 120. A drive current I1.

Because the overcurrent protection mechanism is activated, it is based on the The detection current Io1 is determined by the magnitude of the first dynamic reference current Iref1. Therefore, the size setting of the first dynamic reference current Iref1 is also the key to whether the overcurrent protection mechanism can be started in time. In the present invention, the first dynamic reference current Iref1 is generated by the first dynamic reference current generating module 16.

Please refer to Figure 2. 2 is a circuit diagram of a first dynamic reference current generating module 16 in accordance with an embodiment of the present invention. In the embodiment, the first dynamic reference current generating module 16 includes a temperature-varying current generating circuit 20 and a voltage-variable current generating circuit 22.

The temperature-varying current generating circuit 20 is configured to generate a temperature-varying current It that varies with temperature. In the present embodiment, the temperature-varying current It has a negative temperature coefficient, that is, its magnitude will change in a negative direction with temperature. When the temperature rises, the temperature change current It will drop, and when the temperature drops, the temperature change current It will rise. In the present embodiment, the temperature-variable current generating circuit 20 actually generates a temperature-varying voltage Vn having a negative temperature coefficient to generate a temperature-varying current having a negative temperature characteristic according to the temperature-varying voltage Vn and the resistor Rs. .

The voltage-variable current generating circuit 22 is for generating a voltage-variable current Iv that varies with voltage. In this embodiment, the voltage-variable current Iv has a positive voltage coefficient, that is, its magnitude will change in a negative direction with voltage. When the supply voltage VDD rises, the voltage change current Iv will rise, and when the supply voltage VDD drops, the voltage change current Iv will decrease.

Therefore, by subtracting the voltage-variable current Iv from the temperature-varying current It (corresponding to negatively outputting the pressure-variable current Iv and adding it to the temperature-varying current It), the current is output via a current mirror 24, and a negative temperature can be obtained. And a first dynamic reference current Iref1 of a negative voltage coefficient characteristic.

Since the transistor is more prone to latch-up at higher voltages, and the metal current density of the transistor is lower at higher temperatures, it is easy to generate an uncontrolled amount of current. Therefore, in these two situations, it is better to set the first dynamic reference current Iref1 at a lower level to quickly activate the overcurrent protection mechanism. Therefore, when the temperature or voltage of the system rises, the first dynamic reference current Iref1 with negative temperature and negative voltage coefficient characteristics can be dynamically turned down, so that the overcurrent protection mechanism can be started faster, achieving better. Protection effect.

The temperature-varying current generating circuit 20 and the voltage-variable current generating circuit 22 described above are merely exemplary embodiments. In other embodiments, the voltage change current Iv and the temperature change current It may also be generated by other circuit architectures, and are not limited by the architecture of FIG.

It should be noted that the above description is based on the adjustment mechanism of the source current (ie, the first driving current I1). As shown in FIG. 1, the protection circuit 14 may further include a second switching control unit 141 and a second adjustment unit 143. Similarly, the second switching control unit 141 can include the second detecting component 145 and the second current comparator 147 to generate the second dynamic reference current Iref2 and the second detecting current generated by the second dynamic reference current generating module 18. Io2 generates a second switching control signal Vc2. When the output terminal O is connected to the supply voltage terminal and the potential value of the output signal Vout is equivalent to VDD, the second driving current I2 will rise to increase the second detection current Io2 and be greater than the second dynamic reference current Iref2. . Therefore, the second switching control signal Vc2 will enable the second adjusting unit 143 to initiate the mechanism of overcurrent protection.

In different embodiments, the overcurrent protection of the first adjusting unit 142 The mechanism can also be implemented in different ways. Please refer to Figure 3. Fig. 3 is a circuit diagram of the arithmetic circuit 3 in accordance with an embodiment of the present invention. In the embodiment, the first adjusting unit 142 includes a current source 30 and a switching element 32. The switching component 32 can be switched according to the voltage level of the first switching control signal Vc1. In this embodiment, the switching element 32 is in an open state when the first switching control signal Vc1 is at a low level. When the first switching control signal Vc1 is at a high level, it is turned on to activate an overcurrent protection mechanism to couple the current source 30 to the first output terminal Out1 and provide a control current Ic. The control current Ic will cause the voltage of the first control signal Vp to rise, causing the voltage difference between the gate and the source of the first driving element 120 to decrease, further reducing the value of the first driving current I1. Similarly, the second adjusting unit 143 may also include the same structure, and thus will not be described again.

Please refer to Figure 4. Fig. 4 is a circuit diagram of the arithmetic circuit 4 in an embodiment of the present invention. The structure of the first adjusting unit 142 in FIG. 4 is similar to that shown in FIG. 3. However, in this embodiment, the first dynamic reference current generating module 16 can generate two first changes with temperature and voltage. The dynamic reference currents Iref1_1 and Iref1_2 are alternately output, wherein the value of the first dynamic reference current Iref1_2 is smaller than the first dynamic reference current Iref1_1. In normal operation, the first dynamic reference current generation module 16 outputs the first dynamic reference current Iref1_1. When the first switching control signal Vc1 is at a high level, in addition to starting the overcurrent protection mechanism, the current source 30 is coupled to the first output terminal Out1, and the first dynamic reference current generating module 16 is also outputted to the first dynamic state. Referring to the current Iref1_2, thereby forcing the voltage of the first control signal Vp to continuously rise by providing the control current Ic, thereby latching the first driving current I1 Lower current value.

Therefore, the present invention has the advantages of providing a more flexible overcurrent protection mechanism by providing a reference current value that can be dynamically adjusted with the operating environment of the system by temperature change and voltage change current.

The present disclosure has been disclosed in the above embodiments, but it is not intended to limit the disclosure, and any person skilled in the art can make various changes and refinements without departing from the spirit and scope of the disclosure. The scope of protection of the disclosure is subject to the definition of the scope of the patent application.

16‧‧‧First Dynamic Reference Current Generation Module

20‧‧‧temperature change current generation circuit

22‧‧‧Pressure current generation circuit

24‧‧‧current mirror

Claims (10)

An arithmetic circuit with an overcurrent protection mechanism, comprising: a first circuit stage, comprising: receiving a first input end of an input signal and receiving a second input end of an output signal, according to the input signal and the output signal Generating a first control signal at a first output terminal and generating a second control signal at a second output terminal; a second circuit stage coupled to the first circuit level to be based on a first drive current and a The second driving current generates the output signal, wherein the first driving current is generated by the first control signal, and the second driving current is controlled by the second control signal; a protection circuit coupled to the first circuit level And the second circuit stage is configured to detect the first driving current to selectively adjust the first control signal, wherein the protection circuit comprises: a first switching control unit, configured to be based on the first driving current Generating a first detection current and a first dynamic reference current for comparison to generate a first switching control signal; and a first adjusting unit, one end coupled to the first a first supply unit is coupled to the first output end of the first circuit level, wherein the first adjustment unit adjusts the first control signal when the first switching control signal is at a uniform level; A first dynamic reference current generating module is configured to generate the first dynamic reference current according to a voltage-variable current generated by a voltage-variable current generating circuit and a temperature-varying current generated by a temperature-varying current generating circuit. The operation circuit of claim 1, wherein the temperature change current is a negative temperature coefficient current, and the pressure change current is a positive voltage coefficient current, the first The dynamic reference current generation module subtracts the temperature change current and the pressure change current to generate the first dynamic reference current. The arithmetic circuit of claim 1, wherein the first driving current is one of the sourcing currents of the second circuit level. The arithmetic circuit of claim 1, wherein the first driving current is a sinking current of one of the second circuit stages. The operation circuit of claim 1, wherein the first adjustment unit adjusts the first control signal to decrease the first drive current when the first detection current is greater than the first dynamic reference current. The operation circuit of claim 1, wherein the second circuit stage comprises: a first driving component coupled to the first output terminal to receive the first control signal and generate the first driving current; The second driving component is coupled to the second output terminal to receive the second control signal and generate the second driving current. The operation circuit of claim 6, wherein the first switching control unit comprises: a first detecting component coupled to the first output terminal to detect the first driving current and generate the first detecting And a first current comparator coupled to the first detecting component and the first dynamic reference current generating module to detect the first detecting current and the first motion The state reference currents are compared to generate the first switching control signal. The operation circuit of claim 1, wherein the first adjustment unit comprises a current source and a switching element, wherein the current source provides a control current to the first when the switching element is enabled for the first switching control signal A control signal. The operation circuit of claim 1, wherein the protection circuit further comprises: a second dynamic reference current generation module for providing a second dynamic reference current; and a second switching control unit for The second driving current generates a second detecting current and the second dynamic reference current for comparison to generate a second switching control signal; and a second adjusting unit, one end is coupled to a second supply voltage, and the other end is coupled The second control unit is configured to adjust the second control signal when the second switching control signal is at the enable level. The arithmetic circuit of claim 1, wherein the first circuit stage is an operational amplifier.