Description

Technical Field

The present invention relates to the technical field of circuit protection, in particular to a switching circuit with output short-circuit protection, a vehicle lamp, and a vehicle.

A high-side switch is used for performing switching operations at the power supply end of a load, with its input terminal being connected to a power source and its output terminal being connected to the load; a high-side switch is also realizable by using a transistor, a MOSFET, etc.

When a high-side switch is turned on, little internal resistance or voltage drop occurs; when the output terminal is short-circuited to ground, a current passing through the high- side switch instantly rises to a large value; if the high-side switch is not turned off in a timely manner, the high-side switch and even the power source will burn out and, in serious cases, a fire will break out.

Summary of the Invention

Therefore, an objective of the present invention is to provide a high-side switching circuit with output short-circuit protection that is capable of at least partially solving the above-described problem.

One aspect of the present invention provides a high-side switching circuit with output short-circuit protection, the input terminal of the high- side switching circuit being coupled to a power source, the output terminal of the high-side switching circuit being coupled to a load; the high-side switching circuit comprises: a high- side switch comprising a plurality of terminals, the plurality of terminals including the input terminal and the output terminal; a high-side switch control circuit, coupled to at least one of the plurality of terminals of the high-side switch and for controlling the turn-on and turn-off of the high-side switch; an output short-circuit protection circuit, coupled to the high-side switch control circuit; and an output short-circuit feedback circuit, coupled to the output short-circuit protection circuit and the output terminal; and when the output terminal is short-circuited to ground, the output short-circuit feedback circuit triggers the output short-circuit protection circuit to start operating, thereby causing the high-side switch control circuit to control the high-side switch to be turned off.

According to one embodiment of the present application, when the output terminal of the high- side switching circuit is short-circuited to ground, a very short time has elapsed from the output terminal being short-circuited to the ground until the turn-off of the high- side switch, and only an instantaneous high current has passed through the high-side switch; therefore, the high-side switch and even the power source may be protected from burning out.

In some embodiments, when the output terminal is short-circuited to ground, the output short-circuit protection circuit causes the high-side switch control circuit to be broken, thereby causing the high-side switch to be turned off.

In some embodiments, when the output terminal has changed from being short-circuited to ground to not being short-circuited to ground, the output short-circuit protection circuit causes the high-side switch control circuit to remain in a broken state, thereby keeping the high-side switch in an off state.

According to one embodiment of the present application, when the output terminal has changed from being short-circuited to ground to not being short-circuited to ground, keeping the high-side switch in an off state makes it possible to further protect the high-side switch from burning out when the output terminal is switched many times between a state of being short-circuited to ground and a state of not being short-circuited to ground.

In some embodiments, when the output terminal is short-circuited to ground, the output short-circuit protection circuit causes the high-side switch control circuit to be conductive, thereby causing the high-side switch to be turned off.

In some embodiments, when the output terminal has changed from being short-circuited to ground to not being short-circuited to ground, the output short-circuit protection circuit causes the high-side switch control circuit to remain in a conductive state, thereby keeping the high-side switch in an off state.

According to one embodiment of the present application, when the output terminal has changed from being short-circuited to ground to not being short-circuited to ground, keeping the high-side switch in an off state makes it possible to further protect the high-side switch from burning out when the output terminal is switched many times between a state of being short-circuited to ground and a state of not being short-circuited to ground.

In some embodiments, the high- side switch (110) comprises a first transistor (Ql), emitter of the first transistor (Ql) being used as the input terminal, collector of the first transistor (Ql) being used as the output terminal, base of the first transistor (Ql) being coupled to the high-side switch control circuit (120).

In some embodiments, the high-side switch control circuit comprises an enable signal, a first resistor, a first MOSFET, and a second resistor; when the first MOSFET is turned off, the high-side switch control circuit is broken; the enable signal and the output short-circuit protection circuit jointly control the turn on and turn-off of the first MOSFET; and the enable signal is coupled to one end of the first resistor, the other end of the first resistor is coupled to the gate of the first MOSFET, the source of the first MOSFET is grounded, the drain of the first MOSFET is coupled to one end of the second the resistor, and the other end of the second resistor is coupled to the base of the first transistor.

In some embodiments, the output short-circuit protection circuit comprises a third resistor, a fourth resistor, a capacitor, a second transistor, and a third transistor, wherein one end of the third resistor is coupled to the first resistor, and the other end of the third resistor is coupled to the fourth resistor; the other end of the fourth resistor is coupled to the capacitor, the collector of the second transistor, and the base of the third transistor; the other end of the capacitor is grounded; the base of the second transistor is coupled to the collector of the third transistor, the emitter of the second transistor (Q3) is coupled to the first resistor (R2) and the gate of the first MOSFET (Q2); and the emitter of the third transistor is grounded.

In some embodiments, the output short-circuit protection circuit comprises a third resistor, a capacitor, and a third transistor, wherein one end of the third resistor is coupled to the first resistor, and the other end of the third resistor is coupled to the capacitor and the base of the third transistor; the other end of the capacitor is grounded; and the collector of the third transistor (Q4) is coupled to the first resistor (R2) and the gate of the first MOSFET (Q2), the emitter of the third transistor is grounded.

In some embodiments, the output short-circuit feedback circuit comprises a second MOSFET, the drain of the second MOSFET being coupled to the third resistor and the fourth resistor, the gate of the second MOSFET being coupled to the collector of the first transistor and a load, the source of the second MOSFET being grounded.

In some embodiments, the output short-circuit feedback circuit comprises a second MOSFET, the drain of the second MOSFET being coupl ed to the third resistor, the capacitor, and the base of the third transistor, the gate of the second MOSFET being coupled to the collector of the first transistor and a load, the source of the second MOSFET being grounded.

Another aspect of the present invention provides a vehicle lamp comprising any of the above-described high-side switching circuits.

Another aspect of the present invention provides a vehicle comprising any of the above- described vehicle lamps.

Brief Description of the Drawings

The above-mentioned characteristics, technical features, advantages, and modes of implementation of the present invention will be explained in greater detail below by giving a description of preferred embodiments in a clear and easy-to-understand manner with reference to the drawings. Among the drawings,

Figure 1 shows a schematic modular diagram for a high-side switching circuit 100 with output short-circuit protection according to one embodiment of the present invention;

Figure 2 shows a schematic structural diagram for a high-side switching circuit 100 with output short-circuit protection according to one embodiment of the present invention;

Figure 3 shows a schematic structural diagram for a high-side switching circuit 100 with output short-circuit protection according to another embodiment of the present invention;

Figure 4 shows a schematic structural diagram for a high-side switching circuit 100 with output short-circuit protection according to yet another embodiment of the present invention; and

Figure 5 shows a schematic diagram for the voltage waveform of an enable signal ENABLE from any of the high- side switching circuits 100 in Figures 2 to 4, and a schematic diagram for the current waveform of the output terminal when the output terminal is not short-circuited to ground and when the output terminal is short-circuited to ground.

Specific Embodiments

Embodiments of the present invention will be described in an exemplary manner below. As those skilled in the art should realize, the embodiments described may be amended in various ways without departing from the concept of the present invention. Thus, the accompanying drawings and the description are in essence exemplary and non-limiting. In the following text, identical drawing reference labels generally indicate functionally identical or similar elements.

Figure 1 shows a schematic modular diagram for a high-side switching circuit 100 with output short-circuit protection according to one embodiment of the present invention. As shown in the figure, the input terminal of the high-side switching circuit 100 may be coupled to a power source 200, and the output terminal of the high-side switching circuit 100 may be coupled to a load 300, wherein the output terminal may be directly coupled to the load 300 (in this case, the load 300 is known as a passive load), or may be coupled to the load 300 through other power source (in this case, the load 300 is known as an active load). In some other embodiments, the output terminal of the high-side switching circuit 100 may also be coupled to other circuit elements connected in parallel with the circuit where the load 300 is located (comprising the load 300, or comprising the load 300 and the above- described other power source). Circumstances where the output terminal is short-circuited to ground may include, but are not limited to: the circuit where the load 300 is located is short-circuited to ground, other circuit elements connected in parallel with the circuit where the load 300 is located is short-circuited to ground, and the output terminal is directly short- circuited to ground, or other circumstances.

Specifically, the high-side switching circuit 100 may comprise a high-side switch 110, the high-side switch 110 comprising a plurality of terminals that include the input terminal and the output terminal of the high-side switching circuit 100; a high-side switch control circuit 120, coupled to at least one of the plurality of terminals of the high-side switch 110 and for controlling the turn-on and turn-off of the high-side switch 110; an output short- circuit protection circuit 130, coupled to the high-side switch control circuit 120; and an output short-circuit feedback circuit 140, coupled to the output short-circuit protection circuit 130 and the output terminal of the high-side switching circuit 100; when the output terminal of the high-side switching circuit 100 is short-circuited to ground, the output short- circuit feedback circuit 140 can trigger the output short-circuit protection circuit 130 to start operating, thereby causing the high-side switch control circuit 120 to control the high-side switch 110 to be turned off.

In one example, when the output terminal of the high- side switching circuit 100 is short-circuited to ground, the output short-circuit protection circuit 130 can cause the high- side switch control circuit 120 to be broken, thereby causing the high-side switch 110 to be turned off. In one example, when the output terminal of the high-side switching circuit 100 has changed from being short-circuited to ground to not being short-circuited to ground, the output short-circuit protection circuit 130 can cause the high-side switch control circuit 120 to remain in a broken state, thereby keeping the high-side switch 110 in an off state. In another example, when the output terminal of the high-side switching circuit 100 is short-circuited to ground, the output short-circuit protection circuit 130 can cause the high- side switch control circuit 120 to be conductive, thereby causing the high-side switch 110 to be turned off. In another example, when the output terminal of the high-side switching circuit 100 has changed from being short-circuited to ground to not being short-circuited to ground, the output short-circuit protection circuit 130 can cause the high-side switch control circuit 120 to remain in a conductive state, thereby keeping the high-side switch 110 in an off state.

According to one embodiment of the present application, when the output terminal of the high-side switching circuit 100 is short-circuited to ground, a very short time has elapsed from the output terminal being short-circuited to the ground until the turn-off of the high- side switch 110, and only an instantaneous high current has passed through the high-side switch 110; therefore, the high-side switch 110 and even the power source 200 may be protected from burning out.

In addition, if the high-side switch 110 is turned on again when the output terminal has changed from being short-circuited to ground to not being short-circuited to ground, then when the output terminal is switched many times between a state of being short- circuited to ground and a state of not being short-circuited to ground (for example, but not limited to, when the short-circuit joint causing the output terminal to be short-circuited to ground is in poor contact), multiple instantaneous high currents will pass through the high- side switch 110 , which runs the risk of burning the high-side switch 110. Therefore, in one embodiment of the present application, when the output terminal has changed from being short-circuited to ground to not being short-circuited to ground, keeping the high-side switch 110 in an off state further protects the high-side switch 110 from burning out.

The circuit structure of the high-side switching circuit 100 with output short-circuit protection will be specifically described below with reference to two embodiments.

Embodiment 1

Figure 2 shows a schematic structural diagram for a high-side switching circuit 100 with output short-circuit protection according to one embodiment of the present invention. In the example shown in Figure 2, the high-side switch 110 may comprise a first transistor Ql, wherein the first transistor Q1 is a PNP transistor, the emitter of the first transistor Q1 may be used as the input terminal of the high-side switching circuit 100, the collector of the first transistor Ql may be used as the output terminal of the high-side switching circuit 100, and the base of the first transistor Ql may be coupled to the high-side switch control circuit 120.

The high-side switch control circuit 120 may comprise an enable signal ENABLE, a first resistor R2, a first MOSFET Q2, and a second resistor Rl, wherein the enable signal ENABLE is coupled to one end of the first resistor R2, the other end of the first resistor R2 is coupled to the gate of the first MOSFET Q2, the source of the first MOSFET Q2 is grounded, the drain of the first MOSFET Q2 is coupled to one end of the second resistor Rl, and the other end of the second resistor Rl is coupled to the base of the first transistor Ql.

When the first MOSFET Q2 is turned on, it may also be deemed that the high-side switch control circuit is conductive at this point; when the first MOSFET Q2 is turned off, it may also be deemed that the high-side switch control circuit is broken at this point. In addition, in the example shown in Figure 2, the first MOSFET is an n-channel MOSFET.

The enable signal ENABLE can control the turn-on and turn-off of the first MOSFET Q2 jointly with the output short-circuit protection circuit 130, thereby controlling the turnon and turn-off of the first transistor Ql; the waveform of the enable signal ENABLE depends on the control requirement of the first transistor Ql.

As shown in Figure 2, the output short-circuit protection circuit 130 comprises a third resistor R3, a fourth resistor R5, a capacitor Cl, a second transistor Q3, and a third transistor Q4, wherein one end of the third resistor R3 is coupled to the first resistor R2, the gate of the first MOSFET Q2, and the emitter of the second transistor Q3, and the other end of the third resistor R3 is coupled to the fourth resistor R5; the other end of the fourth resistor R5 is coupled to the capacitor Cl, the collector of the second transistor Q3, and the base of the third transistor Q4; the other end of the capacitor Cl is grounded; the base of the second transistor Q3 is coupled to the collector of the third transistor Q4; and the emitter of the third transistor Q4 is grounded, wherein the second transistor Q3 is a PNP transistor, and the third transistor Q4 is an

NPN transistor, wherein, when the second transistor Q3 and the third transistor Q4 are turned on, it may also be deemed that the output short-circuit protection circuit 130 is operating at this point, and when the second transistor Q3 and the third transistor Q4 are turned off, it may also be deemed that the output short-circuit protection circuit 130 is not operating at this point.

The output short-circuit feedback circuit 140 comprises a second MOSFET Q5, wherein the second MOSFET Q5 is an n-channel MOSFET, the drain of the second MOSFET Q5 is coupled to the third resistor R3 and the fourth resistor R5, the gate of the second MOSFET Q5 is coupled to the collector of the first transistor Q1 and the load 300, and the source of the second MOSFET Q5 is grounded.

The operating principle of the high-side switching circuit 100 shown in Figure 2 will be described in detail below.

When the enable signal ENABLE is at a high level and the output terminal of the high- side switching circuit 100 is not short-circuited to ground, the enable signal ENABLE charges the capacitor Cl via the first resistor R2, the third resistor R3, and the fourth resistor R5 , and the potentials of the collector of the second transistor Q3 and the base of the third transistor Q4 increase gradually; before the potential causes the second transistor Q3 and the third transistor Q4 to be turned on, for the first MOSFET Q2, the gate-source voltage VGS > threshold voltage Vos(th), and the first MOSFET Q2 is turned on; for the first transistor Ql, since the first MOSFET Q2 is turned on, its emitter potential U _e = V _BAT > base potential U _b , wherein V _BAT is the voltage of the power source 200, the first transistor Ql is also turned on, and the voltage of the output terminal of the high-side switching circuit 100 will get close to the voltage V _BAT of the input terminal; for the second MOSFET Q5, the gate-source voltage VGS ~ V _BAT > threshold voltage Vos _(th) , the second MOSFET Q5 is turned on, the enable signal ENABLE stops charging the capacitor Cl, the potentials of the collector of the second transistor Q3 and the base of the third transistor Q4 stop rising, and the second transistor Q3 and the third transistor Q4 will remain in an off state; in other words, the output short-circuit protection circuit 130 does not operate, which allows the first MOSFET Q2 and the first transistor Q1 to remain in an on state.

It should be noted that, in embodiments of the present invention, high level of the enable signal ENABLE refers to a voltage which causes the first MOSFET Q2 to be turned on, for example, a voltage higher than the threshold voltage V _GS(th) of the first MOSFET Q2, for example, but not limited to, 5 V.

When the enable signal ENABLE is at a low level, regardless of whether the output terminal of the high-side switching circuit 100 is short-circuited to ground, for the first MOSFET Q2, the gate-source voltage Vos < threshold voltage Vos _(th) , and the first MOSFET Q2 is turned off, so that the first transistor Ql is also turned off.

It should be noted that in embodiments of the present invention, low level of the enable signal ENABLE refers to a voltage which causes the first MOSFET Q2 to be turned off, for example, a voltage lower than the threshold voltage VGs(th) of the first MOSFET Q2, for example, but not limited to, 0 V.

When the enable signal ENABLE is at a high level (for example, but not limited to, 5 V), if the output terminal of the high-side switching circuit 100 is short-circuited to ground, then for the second MOSFET Q5, the gate-source voltage Vos = 0 < threshold voltage Vos _(th) , the second MOSFET Q5 is turned off, the enable signal ENABLE continues to charge the capacitor Cl, and the potentials of the collector of the second transistor Q3 and the base of the third transistor Q4 continue to rise; for the third transistor Q4, when the base potential U _b > emitter potential U _e , the third transistor Q4 is turned on, and for the second transistor Q3, when the emitter potential U _e > base potential U _b , the second transistor Q3 is also turned on, at which point the output short-circuit protection circuit 130 starts operating; for the first MOSFET Q2, since the second transistor Q3 and the third transistor Q4 are turned on, its gate potential is pulled down, the gate-source voltage VGS < threshold voltage Vos _(th) , and the first MOSFET Q2 is turned off, causing the first transistor Ql to be also turned off.

After the output short-circuit protection circuit 130 starts operating, assuming that the enable signal ENABLE remains at a high level and that the output terminal of the high-side switching circuit 100 is coupled to an active load, then, if the output terminal of the high- side switching circuit 100 lias changed from being short-circuited to ground to not being short-circuited to ground, since the load 300 is an active load, the potential of the output terminal of the high-side switching circuit 100 will rise so that the second MOSFET Q5 is turned on; however, due to the existence of the fourth resistor R5, the base potential of the third transistor Q4 can still allow the third transistor Q4 and the second transistor Q3 to remain on, so that the first MOSFET Q2 and the first transistor Q1 remain off. In this case, the first MOSFET Q2 and the first transistor Q1 may be turned on only by causing the enable signal ENABLE to change from a high level to a low level and then from a low level to a high level.

After the output short-circuit protection circuit 130 starts operating, assuming that the enable signal ENABLE remains at a high level and that the output terminal of the high-side switching circuit 100 is coupled to a passive load, then, if the output terminal of the high- side switching circuit 100 has changed from being short-circuited to ground to not being short-circuited to ground, the potential of the output terminal of the high-side switching circuit 100 will not rise, the second MOSFET Q5 remains off, and the third transistor Q4 and the second transistor Q3 remain on, so that the first MOSFET Q2 and the first transistor Q1 remain off. In this case, the first MOSFET Q2 and the first transistor Q1 may be turned on only by causing the enable signal ENABLE to change from a high level to a low level and then from a low level to a high level.

Figure 3 shows a modified embodiment of the high-side switching circuit 100 shown in Figure 2. In the high-side switching circuit 100 shown in Figure 3, one end of the first resistor R2 is coupled to the enable signal ENABLE and the third resistor R3, and the other end of the resistor R2 is coupled to the gate of the first MOSFET Q2 and the emitter of the second transistor Q3; other parts and operating principles are the same as those of the high- side switching circuit 100 shown in Figure 2. In Figure 3, the first resistor R2 does not affect the charge time of the capacitor C 1.

Embodiment 2

Figure 4 shows a schematic structural diagram for a high-side switching circuit 100 with output short-circuit protection according to another embodiment of the present invention. Compared with the high-side switching circuit 100 shown in Figure 2, the only difference exhibited by the high-side switching circuit 100 shown in Figure 4 is the output short-circuit protection circuit 130; therefore, the following description will focus on the output short-circuit protection circuit 130; for other parts, reference may be made to the related description of Figure 2 above.

As shown in Figure 4, the output short-circuit protection circuit 130 of the high-side switching circuit 100 comprises a third resistor R3, a capacitor Cl, and a third transistor Q4, wherein one end of the third resistor R3 is coupled to the first resistor R2, the gate of the first MOSFET Q2, and the collector of the third transistor Q4, and the other end of the third resistor R3 is coupled to the drain of the second MOSFET Q5, the capacitor Cl, and the base of the third transistor Q4; the other end of the capacitor Cl is grounded; and the emitter of the third transistor Q4 is grounded, wherein, when the third transistor Q4 is turned on, it may also be deemed that the output short-circuit protection circuit 130 is operating at this point, and when the third transistor Q4 is turned off, it may also be deemed that the output short-circuit protection circuit 130 is not operating at this point.

The operating principle of the high-side switching circuit 100 shown in Figure 4 will be described in detail below.

When the enable signal ENABLE is at a high level (for example, but not limited to, 5 V) and the output terminal of the high-side switching circuit 100 is not short-circuited to ground, the enable signal ENABLE charges the capacitor Cl via the first resistor R2 and the third resistor R3, and the potential of the base of the third transistor Q4 increases gradually; before the potential causes the third transistor Q4 to be turned on, for the first MOSFET Q2, the gate-source voltage V _GS > threshold voltage Vos _(th) , and the first MOSFET Q2 is turned on; for the first transistor Ql, since the first MOSFET Q2 is turned on, its emitter potential U _e = V _BAT > base potential U _b , wherein V _BAT is the voltage of the power source 200, the first transistor Ql is also turned on, and the voltage of the output terminal of the high-side switching circuit 100 will get close to the voltage V _BAT of the input terminal; for the second MOSFET Q5, the gate-source voltage VGS ~ V _BAT > threshold voltage VGS( _th ), the second MOSFET Q5 is turned on, the enable signal ENABLE stops charging the capacitor Cl, the potential of the base of the third transistor Q4 stops rising, and the third transistor Q4 will remain in an off state; in other words, the output short-circuit protection circuit 130 does not operate, which allows the first MOSFET Q2 and the first transistor Q1 to remain in an on state.

When the enable signal ENABLE is at a low level (for example, but not limited to, 0 V), regardless of whether the output terminal of the high-side switching circuit 100 is short- circuited to ground, for the first MOSFET Q2, the gate-source voltage Vos < threshold voltage Vosi _th) , and the first MOSFET Q2 is turned off, so that the first transistor Q1 is also turned off.

When the enable signal ENABLE is at a high level (for example, but not limited to, 5 V), if the output terminal of the high-side switching circuit 100 is short-circuited to ground, then for the second MOSFET Q5, the gate-source voltage Vos = 0 < threshold voltage V _GS(th) , the second MOSFET Q5 is turned off, the enable signal ENABLE continues to charge the capacitor Cl, and the potential of the base of the third transistor Q4 continues to rise; for the third transistor Q4, when the base potential U _b > emitter potential U _e , the third transistor Q4 is turned on, at which point the output short-circuit protection circuit 130 starts operating; for the first MOSFET Q2, since the third transistor Q4 is turned on, its gate potential is pulled down, the gate-source voltage VGS < threshold voltage V _GS(th) , and the first MOSFET Q2 is turned off, causing the first transistor Q1 to be also turned off.

After the output short-circuit protection circuit 130 starts operating, assuming that the enable signal ENABLE remains at a high level and that the output terminal of the high-side switching circuit 100 is coupled to a passive load, then, if the output terminal of the high- side switching circuit 100 has changed from being short-circuited to ground to not being short-circuited to ground, the potential at the output terminal of the high-side switching circuit 100 will not rise, the second MOSFET Q5 remains off, and the third transistor Q4 remains on, so that the first MOSFET Q2 and the first transistor Q1 remain off. In this case, the first MOSFET Q2 and the first transistor Q1 may be turned on only by causing the enable signal ENABLE to change from a high level to a low level and then from a low level to a high level.

As a modified embodiment, the high- side switching circuit 100 shown in Figure 4 may also be provided with the high-side switch control circuit 120 shown in Figure 3. In this case, the first resistor R2 does not affect the charge time of the capacitor Cl.

From the operating principle of the high-side switching circuit 100 of the above- described embodiments 1 and 2, it is clear that when the output terminal of the high-side switching circuit 100 is short-circuited to ground, a high current flows through the emitter and collector of the first transistor Q1 only during a very short time period At from turn-off of the second MOSFET Q5 to turn-on of the second transistor Q3 and the third transistor Q4 (or turn-on of the third transistor Q4); therefore, the first transistor Ql, namely, the high- side switch 110 and the power source 200, may be protected from burning out.

In addition, the length of the time period At is related to the charging parameters of the capacitor Cl; for the embodiment shown in Figure 2, it is related to the resistance of the first resistor R2, the resistance of the third resistor R3, the resistance of the fourth resistor R5, and the capacitance of capacitor Cl; for the embodiment shown in Figure 3, it is related to the resistance value of the third resistor R3, the resistance of the fourth resistor R5, and the capacitance of the capacitor Cl; for the embodiment shown in Figure 4, it is related to the resistance of the first resistor R2, the resistance of the third resistor R3, and the capacitance of the capacitor Cl. Therefore, the length of the time period At is adjustable by setting these parameter values.

In one example, these parameter values may be set while maintaining a balance between the anti-interference ability of the output short-circuit protection circuit 130 and the impact resistance ability of the high-side switch 110. The anti-interference ability of the output short-circuit protection circuit 130 refers to the ability to prevent interference from erroneously triggering the output short-circuit protection circuit 130 to start operating; in the above-described embodiments 1 and 2, it refers to the ability to prevent interference from causing the second transistor Q3 and the third transistor Q4 (or the third transistor Q4) to be turned on erroneously. Said interference may include, but is not limited to, conduction interference introduced by the input terminal, the output terminal, and the control terminal of the enable signal ENABLE, electromagnetic coupling interference from the environment outside the circuit, and interference caused by a sudden current change on the circuit of the high-side switch 110 at the instant of its turn-on or turn-off. Examples of the above- described interference erroneously triggering the output short-circuit protection circuit 130 to start operating may include, but are not limited to, the base potential of the third transistor Q4 being pulled up by interference, the gate potential of the second MOSFET Q5 being pulled down by interference, the gate potential of the first MOSFET Q2 being pulled down by interference which causes the output to be turned off for a short time, and the base potential of the first transistor Q1 being pulled up by interference which causes the output to be turned off for a short time.

Figure 5 shows a schematic diagram for the voltage waveform of an enable signal ENABLE from any of the high-side switching circuits 100 in Figures 2 to 4, and a schematic diagram for the current waveform of the output terminal when the output terminal is not short-circuited to ground and when the output terminal is short-circuited to ground, wherein "OUTPUT STATUS" indicates the status of the output terminal of the high-side switching circuit 100, "NORMAL" indicates that the output terminal is not short-circuited to ground, and "SHORT CIRCUIT" indicates that the output terminal is short-circuited to ground; "OUTPUT CURRENT" indicates the current of the output terminal .

As shown in Figure 5, when the enable signal ENABLE is at a high level and the output terminal of the high- side switching circuit 100 has changed from not being short- circuited to ground to being short-circuited to ground, an instantaneous high current flows through the output terminal of the high-side switching circuit 100, and after the output short- circuit protection circuit 130 is triggered, no current flows through the output terminal of the high-side switching circuit 100. In addition, after the output short-circuit protection circuit 130 is triggered, if the output terminal of the high-side switching circuit 100 has changed from being short-circuited to ground to not being short-circuited to ground, since the second transistor Q3 and the third transistor Q4 (or the third transistor Q4) remain on, the high-side switch 110 also remains off; the high-side switch 110 will not be turned on until the enable signal ENABLE has changed to a low level and then to a high level. It should be noted that the high-side switch 110 is not limited to the PNP transistor Q1 in the above-described embodiment; the high-side switch 110 may also be an NPN transistor, or other type of element possessing turn-on and turn off state, for example, a MOSFET or a relay. In addition, the control logic of the high-side switch control circuit 120, instead of being limited to the above-described embodiment, may also be that the high-side switch control circuit 120, when conductive, controls the high-side switch 110 to be turned off , and that the high-side switch control circuit 120, when broken, controls the high-side switch 110 to be turned on.

For the high-side switch control circuit 120 in the above-described embodiment, the second MOSFET Q2 may also be replaced with a p-channel MOSFET, a transistor, etc.

For the output short-circuit protection circuit 130 in the above-described embodiment, the second transistor Q3 may also be replaced with an NPN transistor or a MOSFET, and the third transistor Q4 may also be replaced with a PNP transistor or a MOSFET. However, the second transistor Q3 and the third transistor Q4 should be different types of transistors; for example, the second transistor Q3 is a p-channel MOSFET, and the third transistor Q4 is an n-channel MOSFET. The output short-circuit feedback circuit 140 may also be a p- channel MOSFET, a transistor, etc.

While the connection structure of the circuit will be changed when the above- mentioned replacement is made, it is understandable that such a change will not depart from the principle or spirit embodied by the present general disclosure.

In embodiments of the present invention, by the disposition of the output short-circuit feedback circuit 140, when the output terminal of the high-side switching circuit 100 is short-circuited to ground, the output short-circuit protection circuit 130 is triggered to start operating, so that the high-side switch 110 is turned off in a timely manner, which protects the high-side switch 110 and even the power source 200 from burning out.

Further, the present invention is implemented completely by hardware circuits, carrying a low cost, giving rapid responses, and capable of ensuring that the high-side switch 110 is turned off in a timely manner.

The present invention further provides a vehicle lamp comprising any of the above- described high- side switching circuits. In one example, the high- side switching circuit may be used to drive components in a vehicle lamp, including, but not limited to, LEDs, solenoids, and drivers. In this case, circumstances that cause the output terminal of the high-side switching circuit to be short-circuited to ground may include, but are not limited to, vibration of the vehicle when it is driven, or corrosion of the pad of a terminal. In addition, in the above-described embodiment, the waveform of the enable signal ENABLE may depend on the driver's requirements for controlling the vehicle lamp.

The present invention further provides a vehicle comprising the vehicle lamp as described above.

It should be noted that a high-side switching circuit of the present invention, instead of being limited to being used to drive components in a vehicle lamp, may be used to drive any suitable load as required.

The present invention, instead of being limited to the above-described structure, may adopt other various modified structures. Although the present invention has already been described by means of a limited number of embodiments, those skilled in the art could, drawing benefit from this disclosure, design other embodiments which do not depart from the scope of protection of the present invention disclosed herein. Thus, the scope of protection of the present invention should be defined by the attached claims alone.