CN102130573B - Multi-output step-down conversion device with shutdown protection - Google Patents

Abstract

The invention discloses a multi-group output buck conversion device with shutdown protection, which comprises a main buck converter and at least one auxiliary buck converter to provide a plurality of groups of output power supplies. The multi-output buck conversion device further comprises an abnormal voltage signal generating unit. When the multi-group output buck converter is shut down, the abnormal voltage signal generating unit generates a control signal pair to control the switching element of the buck converter, so that the energy stored by the auxiliary buck converter can be released through an internal path of the auxiliary buck converter or a path provided by an operation load externally connected with the auxiliary buck converter, and the stored energy is prevented from being returned to the main buck converter to cause the main output voltage to bounce.

Description

Multi-output step-down conversion device with shutdown protection

technical field

The invention relates to a step-down conversion device, in particular to a multi-output step-down conversion device with shutdown protection.

Background technique

In the computer system application technology, due to the load requirements of the computer system, there is usually not only a single set of output. Therefore, in order to provide multiple sets of output power, the power supply usually uses a step-down converter to drop the original single set of output voltage. For the required voltage value, in order to achieve the requirements of multiple sets of output. When the power supply provides multiple sets of stable outputs and cooperates with the timing actions that meet the requirements of the motherboard, the computer system can operate normally. However, due to the natural characteristics of the step-down converter, the roles played by the input terminal and the output terminal will be reversed when the power is turned off, so that the original buck converter becomes a boost converter. Converter, causing the output voltage that was originally input to bounce up. In this case, the abnormal output voltage will cause an error in the timing required by the computer system, so that the computer system cannot be shut down normally.

Therefore, how to design a multi-output step-down conversion device with shutdown protection under the use of multiple output power supplies provided by the power supply. When the multi-output step-down conversion device is shut down, it can effectively eliminate The problem of the main output voltage jumping up of the multi-group output step-down conversion device and solving the situation that cannot be shut down normally is a major problem that the applicant of the present invention wants to overcome and solve.

Contents of the invention

In order to solve the above problems, the present invention provides a multi-output step-down conversion device with shutdown protection. The multi-output step-down conversion device includes a main step-down converter and at least an auxiliary step-down converter to provide a plurality of output power sources. Wherein, the main buck converter has a main output terminal to provide a main output voltage relative to the reference ground terminal. The auxiliary buck converter is electrically connected to the main buck converter, includes an upper arm switch and a lower arm switch, and has an auxiliary output terminal for providing an auxiliary output voltage relative to a reference ground. The multi-output step-down conversion device with shutdown protection further includes an abnormal voltage signal generating unit.

The abnormal voltage signal generating unit is electrically connected to the input end of the main step-down converter to generate a control signal pair, wherein the control signal pair includes an upper arm control signal and a lower arm control signal. When multiple sets of output step-down conversion devices are turned off, the upper arm control signal and the lower arm control signal are not at high potential at the same time, so as to respectively control the upper arm switch and the lower arm switch.

In this way, the control signal pair controls the upper arm switch and the lower arm switch of the auxiliary buck converter, and the energy stored in the auxiliary buck converter can be transmitted through the internal path of the auxiliary buck converter or through the auxiliary buck converter. The path provided by the external operating load of the step-down converter is released, preventing the stored energy from feeding back to the main step-down converter, causing the main output voltage to bounce.

In order to further understand the technology, means and effects that the present invention adopts to achieve the predetermined purpose, please refer to the following detailed description and accompanying drawings of the present invention. It is believed that the purpose, characteristics and characteristics of the present invention can be obtained from this For specific understanding, however, the accompanying drawings are only for reference and illustration, and are not intended to limit the present invention.

Description of drawings

1A is a circuit diagram of a first embodiment of a multi-output step-down conversion device with shutdown protection of the present invention;

FIG. 1B is a shutdown timing diagram of the multi-group output step-down conversion device according to the first embodiment of the present invention;

2A is a circuit diagram of the second embodiment of the multi-output step-down conversion device with shutdown protection of the present invention;

FIG. 2B is a shutdown timing diagram of the multi-group output step-down conversion device according to the second embodiment of the present invention;

3A is a circuit diagram of a third embodiment of a multi-output step-down conversion device with shutdown protection according to the present invention; and

FIG. 3B is a shutdown timing diagram of the multi-output step-down conversion device according to the third embodiment of the present invention.

Among them, reference signs

30 Transformer 40 First voltage detection unit

50 Second voltage detection unit 70 Abnormal voltage signal generation unit

80 Main Buck Converter 802 Main Upper Arm Switch

804 Main lower arm switch 806 Main output inductor

808 Main output capacitor 810 Auxiliary inductor

812 auxiliary capacitor Vo1 main output terminal

10 First Buck Converter 102 First Upper Arm Switch

104 First lower arm switch 106 First output inductance

108 The first output capacitor Vb1 The first auxiliary output terminal

20 second step-down converter 202 second upper arm switch

204 Second lower arm switch 206 Second output inductor

208 Second output capacitor Vb2 Second auxiliary output terminal

Su1 First upper arm control signal Sd1 First lower arm control signal

Su2 Second upper arm control signal Sd2 Second lower arm control signal

Ld11 the first discharge path Ld12 the second discharge path

Ld13 third discharge path Ld14 fourth discharge path

Ld23 third discharge path Ld24 fourth discharge path

Vac AC power Vb Primary side voltage

Vs Secondary side voltage Vt1 First critical voltage

Vt2 second critical voltage Th hold time

Detailed ways

Relevant technical content and detailed description of the present invention, cooperate accompanying drawing to illustrate as follows:

Please refer to FIG. 1A and FIG. 1B , which are respectively the circuit diagram of the first embodiment of the multi-output step-down conversion device with shutdown protection of the present invention and the shutdown timing diagram of the multi-output step-down conversion device of the first embodiment. . The multi-output step-down conversion device includes a main step-down converter 80 and at least one auxiliary step-down converter for providing multiple sets of output power. In this embodiment, two sets of auxiliary step-down converters are taken as an example for illustration. That is, the multi-set output step-down conversion device includes a first auxiliary step-down converter 10 and a second auxiliary step-down converter 20 . The main buck converter 80 has a main output terminal Vo1 for providing a main output voltage (not shown) relative to a reference ground (not shown). The first auxiliary buck converter 10 is electrically connected to the main buck converter 80, and has a first auxiliary output terminal Vb1 for providing a first auxiliary output voltage (not shown) relative to the reference ground terminal. ), wherein the main output voltage of the main buck converter 80 is higher than the first auxiliary output voltage of the first auxiliary buck converter 10 . In addition, the second auxiliary buck converter 20 is electrically connected to the main buck converter 80, and has a second auxiliary output terminal Vb2 for providing a second auxiliary output voltage ( not shown), wherein the main output voltage of the main buck converter 80 is higher than the second auxiliary output voltage of the second auxiliary buck converter 20 .

The multi-output step-down conversion device with shutdown protection further includes an abnormal voltage signal generating unit 70 . The abnormal voltage signal generation unit 70 generates a plurality of control signal pairs (not shown). Taking the two sets of auxiliary step-down converters in this embodiment as an example, the abnormal voltage signal generating unit 70 generates two pairs of control signals. That is, the abnormal voltage signal generating unit 70 generates a first control signal pair and a second control signal pair. Moreover, the first control signal pair includes a first upper arm control signal Su1 and a first lower arm control signal Sd1 , and the second control signal pair includes a second upper arm control signal Su2 and a second lower arm control signal Sd2 . In addition, when the multiple sets of output step-down conversion devices are not shut down (that is, in normal operation), the first upper arm control signal Su1 and the first lower arm control signal Sd1 are pulse width modulation (PWM) signals with complementary potentials. , that is, when the first upper arm control signal Su1 is at a high potential, then the first lower arm control signal Sd1 is at a low potential, and vice versa. Likewise, the second upper arm control signal Su2 and the second lower arm control signal Sd2 are pulse width modulation (PWM) signals with complementary potentials.

As shown in FIG. 1A , a pre-transformer 30 is electrically connected to the main step-down converter 80 for energy conversion between primary side input and secondary side output. The main buck converter 80 mainly includes a main upper switch 802 , a main lower switch 804 , a main output inductor 806 , a main output capacitor 808 , an auxiliary inductor 810 and an auxiliary capacitor 812 . The first buck converter 10 mainly includes a first upper arm switch 102 , a first lower arm switch 104 , a first output inductor 106 and a first output capacitor 108 . The second buck converter 20 mainly includes a second upper arm switch 202 , a second lower arm switch 204 , a second output inductor 206 and a second output capacitor 208 .

One embodiment is: a first voltage detection unit 40 is electrically connected to the primary side of the transformer 30 for detecting the primary side voltage Vb of the transformer 30 . The abnormal voltage signal generation unit 70 is electrically connected to the first voltage detection unit 40 and receives the primary side voltage Vb for comparison with a first threshold voltage Vt1 (see FIG. 1B ). When the multiple sets of output step-down conversion devices are shut down, an external AC power supply Vac stops supplying power. Due to the effect of maintaining the voltage due to the capacitance of the system, after a hold-up time (hold-up time) Th, the primary side voltage Vb Gradually decreases. When the primary-side voltage Vb is lower than the first threshold voltage Vt1, the first upper arm control signal Su1 and the first lower arm control signal Sd1 generated by the abnormal voltage signal generating unit 70 are respectively low potential and high potential, The first upper arm switch 102 of the first auxiliary buck converter 10 is controlled to open and the first lower arm switch 104 is respectively controlled to be closed.

Another embodiment is: a second voltage detection unit 50 is electrically connected to the secondary side of the transformer 30 for detecting the secondary side voltage Vs of the transformer 30 . The abnormal voltage signal generation unit 70 is electrically connected to the second voltage detection unit 50, and receives the secondary side voltage Vs for comparison with a second threshold voltage Vt2 (see FIG. 1B ). When the multiple sets of output step-down conversion devices are shut down, the external AC power supply Vac stops supplying power. Due to the effect of maintaining the voltage due to the capacitance of the system, after a hold-up time (hold-up time) Th, the secondary side voltage Vs decreases gradually. When the secondary side voltage Vs is lower than the second threshold voltage Vt2, the first upper arm control signal Su1 and the first lower arm control signal Sd1 generated by the abnormal voltage signal generating unit 70 are respectively low and high. , and respectively control the first upper arm switch 102 of the first auxiliary buck converter 10 to open (open) and the first lower arm switch 104 to close (close).

However, due to the different topology structures developed by the switching power supply, the circuit used for voltage detection is not limited to the above two embodiments.

The shutdown protection operation of the multiple output step-down conversion devices is described in detail below. When the multiple sets of output step-down conversion devices are turned off, the energy stored in the first output capacitor 108 of the first step-down converter 10 can be released through a first discharge path Ld11, This prevents the energy stored in the first output capacitor 108 from being fed back to the main output terminal Vo1 through a third discharge path Ld13 . In addition, the energy stored in the first auxiliary buck converter 10 can also be released through a path (not shown) provided by an external operating load connected to the first auxiliary buck converter 10 . It is worth mentioning that the first discharge path Ld11 is formed by the first output capacitor 108 , the first output inductor 106 and the first lower arm switch 104 . Moreover, the third discharge path Ld13 is formed by the first output capacitor 108 , the first output inductor 106 , the first upper arm switch 102 , the auxiliary inductor 810 , the main output inductor 806 and the main output capacitor 808 .

Similarly, when the plurality of sets of output step-down conversion devices are turned off, the energy stored in the second output capacitor 208 of the second step-down converter 20 can be discharged via a second discharge path Ld12. The energy is released to prevent the energy stored in the second output capacitor 208 from being fed back to the main output terminal Vo1 through a fourth discharge path Ld14 . In addition, the energy stored in the second auxiliary buck converter 20 can also be released through a path (not shown) provided by an external operating load connected to the second auxiliary buck converter 20 . It is worth mentioning that the second discharge path Ld12 is formed by the second output capacitor 208 , the second output inductor 206 and the second lower arm switch 204 . Moreover, the fourth discharge path Ld14 is formed by the second output capacitor 208 , the second output inductor 206 , the second upper arm switch 202 , the auxiliary inductor 810 , the main output inductor 806 and the main output capacitor 808 .

In short, when the multiple sets of output buck converters are shut down, the control signal pair generated by the abnormal voltage signal generating unit 70 controls the first upper arm switch of the first auxiliary buck converter 10 102 and the first lower arm switch 104 and the second upper arm switch 202 and the second lower arm switch 204 of the second auxiliary buck converter 20, so that the first auxiliary buck converter 10 and the The energy stored in the second auxiliary buck converter 20 is provided through the internal paths of the first auxiliary buck converter 10 and the second auxiliary buck converter 20 or through respective external operating loads. path to release, preventing the stored energy from feeding back to the main buck converter 80, causing the main output voltage to bounce.

Please refer to FIG. 2A and FIG. 2B , which are the circuit diagram of the second embodiment of the multi-output step-down conversion device with shutdown protection and the shutdown timing diagram of the multi-output step-down conversion device of the second embodiment, respectively. . The multi-output step-down conversion device includes a main step-down converter 80 and at least one auxiliary step-down converter for providing multiple sets of output power. In this embodiment, two sets of auxiliary step-down converters are taken as an example for illustration. That is, the multi-set output step-down conversion device includes a first auxiliary step-down converter 10 and a second auxiliary step-down converter 20 . The main buck converter 80 has a main output terminal Vo1 for providing a main output voltage (not shown) relative to a reference ground (not shown). The first auxiliary buck converter 10 is electrically connected to the main buck converter 80, and has a first auxiliary output terminal Vb1 for providing a first auxiliary output voltage (not shown) relative to the reference ground terminal. ), wherein the main output voltage of the main buck converter 80 is higher than the first auxiliary output voltage of the first auxiliary buck converter 10 . In addition, the second auxiliary buck converter 20 is electrically connected to the main buck converter 80, and has a second auxiliary output terminal Vb2 for providing a second auxiliary output voltage ( not shown), wherein the main output voltage of the main buck converter 80 is higher than the second auxiliary output voltage of the second auxiliary buck converter 20 .

The multi-output step-down conversion device with shutdown protection further includes an abnormal voltage signal generating unit 70, and the abnormal voltage signal generating unit 70 generates a plurality of control signal pairs (not shown). Taking the two sets of auxiliary step-down converters in this embodiment as an example, the abnormal voltage signal generating unit 70 generates two pairs of control signals. That is, the abnormal voltage signal generating unit 70 generates a first control signal pair and a second control signal pair. Moreover, the first control signal pair includes a first upper arm control signal Su1 and a first lower arm control signal Sd1 , and the second control signal pair includes a second upper arm control signal Su2 and a second lower arm control signal Sd2 . In addition, when the multiple sets of output step-down conversion devices are not shut down (that is, in normal operation), the first upper arm control signal Su1 and the first lower arm control signal Sd1 are pulse width modulation (PWM) signals with complementary potentials. , that is, when the first upper arm control signal Su1 is at a high potential, then the first lower arm control signal Sd1 is at a low potential, and vice versa. Likewise, the second upper arm control signal Su2 and the second lower arm control signal Sd2 are pulse width modulation (PWM) signals with complementary potentials.

As shown in FIG. 2A , a pre-transformer 30 is electrically connected to the main step-down converter 80 for energy conversion between the primary side input and the secondary side output. The main buck converter 80 mainly includes a main upper switch 802 , a main lower switch 804 , a main output inductor 806 , a main output capacitor 808 , an auxiliary inductor 810 and an auxiliary capacitor 812 . The first buck converter 10 mainly includes a first upper arm switch 102 , a first lower arm switch 104 , a first output inductor 106 and a first output capacitor 108 . The second buck converter 20 mainly includes a second upper arm switch 202 , a second lower arm switch 204 , a second output inductor 206 and a second output capacitor 208 .

One embodiment is: a first voltage detection unit 40 is electrically connected to the primary side of the transformer 30 for detecting the primary side voltage Vb of the transformer 30 . The abnormal voltage signal generation unit 70 is electrically connected to the first voltage detection unit 40, and receives the primary voltage Vb for comparison with a first threshold voltage Vt1 (see FIG. 2B ). When the multiple sets of output step-down conversion devices are shut down, an external AC power supply Vac stops supplying power. Due to the effect of maintaining the voltage due to the capacitance of the system, after a hold-up time (hold-up time) Th, the primary side voltage Vb The voltage is gradually reduced. When the voltage of the primary side voltage Vb is lower than the first threshold voltage Vt1, the first upper arm control signal Su1 and the first lower arm control signal Sd1 generated by the abnormal voltage signal generating unit 70 are both low potential, and respectively The first upper arm switch 102 and the first lower arm switch 104 of the first auxiliary buck converter 10 are controlled to be open.

Another embodiment is: a second voltage detection unit 50 is electrically connected to the secondary side of the transformer 30 for detecting the secondary side voltage Vs of the transformer 30 . The abnormal voltage signal generation unit 70 is electrically connected to the second voltage detection unit 50 and receives the secondary voltage Vs for comparison with a second threshold voltage Vt2 (see FIG. 2B ). When the multiple sets of output step-down conversion devices are shut down, the external AC power supply Vac stops supplying power. Due to the effect of maintaining the voltage due to the capacitance of the system, after a hold-up time (hold-up time) Th, the secondary side voltage The Vs voltage gradually decreases. When the voltage of the secondary side voltage Vs is lower than the second threshold voltage Vt2, the first upper arm control signal Su1 and the first lower arm control signal Sd1 generated by the abnormal voltage signal generating unit 70 are both low potential, and The first upper arm switch 102 and the first lower arm switch 104 of the first auxiliary buck converter 10 are respectively controlled to be open.

However, due to the different topology structures developed by the switching power supply, the circuit used for voltage detection is not limited to the above two embodiments.

The shutdown protection operation of the multiple output step-down conversion devices is described in detail below. When the multiple sets of output step-down conversion devices are turned off, since the first upper arm switch 102 and the first lower arm switch 104 of the first auxiliary step-down converter 10 are in an open state, therefore, for storage The energy of the first output capacitor 108 of the first buck converter 10 is released through the path (not marked) provided by the external operating load of the first auxiliary buck converter 10, so as to avoid the first The energy stored in an output capacitor 108 is sent back to the main output terminal Vo1 through a third discharge path Ld23. It is worth mentioning that the third discharge path Ld23 is formed by the first output capacitor 108 , the first output inductor 106 , the first upper arm switch 102 , the auxiliary inductor 810 , the main output inductor 806 and the main output capacitor 808 .

Similarly, when the multiple sets of output buck converters are turned off, since the first upper arm switch 202 and the first lower arm switch 204 of the second auxiliary buck converter 20 are in an open state, therefore , the energy stored in the second output capacitor 208 of the second buck converter 20 is released through the path (not shown) provided by the operating load externally connected to the second auxiliary buck converter 20 , This prevents the energy stored in the second output capacitor 208 from being fed back to the main output terminal Vo1 through a fourth discharge path Ld24 . It is worth mentioning that the fourth discharge path Ld24 is formed by the second output capacitor 208 , the second output inductor 206 , the second upper arm switch 202 , the auxiliary inductor 810 , the main output inductor 806 and the main output capacitor 808 .

In short, when the multiple sets of output buck converters are shut down, the control signal pair generated by the abnormal voltage signal generating unit 70 controls the first upper arm switch of the first auxiliary buck converter 10 102 and the first lower arm switch 104 and the second upper arm switch 202 and the second lower arm switch 204 of the second auxiliary buck converter 20, so that the first auxiliary buck converter 10 and the The energy stored in the second auxiliary step-down converter 20 is released through the paths provided by the respective external operating loads, so as to prevent the stored energy from returning to the main step-down converter 80, causing the main output The voltage bounces up.

Please refer to FIG. 3A and FIG. 3B , which are the circuit diagram of the third embodiment of the multi-output step-down conversion device with shutdown protection and the shutdown timing diagram of the multi-output step-down conversion device of the third embodiment, respectively. . The multi-output step-down conversion device includes a main step-down converter 80 and at least one auxiliary step-down converter for providing multiple sets of output power. In this embodiment, two sets of auxiliary step-down converters are taken as an example for illustration. That is, the multi-set output step-down conversion device includes a first auxiliary step-down converter 10 and a second auxiliary step-down converter 20 . The main buck converter 80 has a main output terminal Vo1 for providing a main output voltage (not shown) relative to a reference ground (not shown). The first auxiliary buck converter 10 is electrically connected to the main buck converter 80, and has a first auxiliary output terminal Vb1 for providing a first auxiliary output voltage (not shown) relative to the reference ground terminal. ), wherein the main output voltage of the main buck converter 80 is higher than the first auxiliary output voltage of the first auxiliary buck converter 10 . In addition, the second auxiliary buck converter 20 is electrically connected to the main buck converter 80, and has a second auxiliary output terminal Vb2 for providing a second auxiliary output voltage ( not shown), wherein the main output voltage of the main buck converter 80 is higher than the second auxiliary output voltage of the second auxiliary buck converter 20 .

The multi-output step-down conversion device with shutdown protection further includes an abnormal voltage signal generating unit 70, and the abnormal voltage signal generating unit 70 generates a plurality of control signal pairs (not shown). Taking the two sets of auxiliary step-down converters in this embodiment as an example, the abnormal voltage signal generating unit 70 generates two pairs of control signals. That is, the abnormal voltage signal generating unit 70 generates a first control signal pair and a second control signal pair. Moreover, the first control signal pair includes a first upper arm control signal Su1 and a first lower arm control signal Sd1 , and the second control signal pair includes a second upper arm control signal Su2 and a second lower arm control signal Sd2 . In addition, when the multiple sets of output step-down conversion devices are not shut down (that is, in normal operation), the first upper arm control signal Su1 and the first lower arm control signal Sd1 are pulse width modulation (PWM) signals with complementary potentials. , that is, when the first upper arm control signal Su1 is at a high potential, then the first lower arm control signal Sd1 is at a low potential, and vice versa. Likewise, the second upper arm control signal Su2 and the second lower arm control signal Sd2 are pulse width modulation (PWM) signals with complementary potentials.

As shown in FIG. 3A , a pre-transformer 30 is electrically connected to the main step-down converter 80 for energy conversion between the primary side input and the secondary side output. The main buck converter 80 mainly includes a main upper switch 802 , a main lower switch 804 , a main output inductor 806 , a main output capacitor 808 , an auxiliary inductor 810 and an auxiliary capacitor 812 . The first buck converter 10 mainly includes a first upper arm switch 102 , a first lower arm switch 104 , a first output inductor 106 and a first output capacitor 108 . The second buck converter 20 mainly includes a second upper arm switch 202 , a second lower arm switch 204 , a second output inductor 206 and a second output capacitor 208 .

One embodiment is: a first voltage detection unit 40 is electrically connected to the primary side of the transformer 30 for detecting the primary side voltage Vb of the transformer 30 . The abnormal voltage signal generation unit 70 is electrically connected to the first voltage detection unit 40, and receives the primary voltage Vb for comparison with a first threshold voltage Vt1 (see FIG. 3B ). When the multiple sets of output step-down conversion devices are shut down, an external AC power supply Vac stops supplying power. Due to the effect of maintaining the voltage due to the capacitance of the system, after a hold-up time (hold-up time) Th, the primary side voltage Vb The voltage is gradually reduced. When the voltage of the primary side voltage Vb is lower than the first threshold voltage Vt1, the first upper arm control signal Su1 and the first lower arm control signal Sd1 generated by the abnormal voltage signal generating unit 70 are high potential and low potential respectively. , respectively controlling the first upper arm switch 102 of the first auxiliary buck converter 10 to close (closed) and the first lower arm switch 104 to open (open).

Another embodiment is: a second voltage detection unit 50 is electrically connected to the secondary side of the transformer 30 for detecting the secondary side voltage Vs of the transformer 30 . The abnormal voltage signal generation unit 70 is electrically connected to the second voltage detection unit 50 and receives the secondary voltage Vs for comparison with a second threshold voltage Vt2 (see FIG. 3B ). When the multiple sets of output step-down conversion devices are shut down, the external AC power supply Vac stops supplying power. Due to the effect of maintaining the voltage due to the capacitance of the system, after a hold-up time (hold-up time) Th, the secondary side voltage The Vs voltage gradually decreases. When the voltage of the secondary side voltage Vs is lower than the second threshold voltage Vt2, the first upper arm control signal Su1 and the first lower arm control signal Sd1 generated by the abnormal voltage signal generating unit 70 are high and low respectively. potential, respectively controlling the first upper arm switch 102 of the first auxiliary buck converter 10 to close (closed) and the first lower arm switch 104 to open (open).

However, due to the different topology structures developed by the switching power supply, the circuit used for voltage detection is not limited to the above two embodiments.

The shutdown protection operation of the multiple output step-down conversion devices is described in detail below. When the multiple sets of output step-down converters are turned off, although the first upper arm switch 102 of the first auxiliary step-down converter 10 is in a closed state, since the first lower arm switch 104 is open ( open) state, therefore, for the energy stored in the first output capacitor 108 of the first buck converter 10, the path provided by the operating load externally connected to the first auxiliary buck converter 10 (not marked ) to release, so that the voltage of the first auxiliary output terminal Vb1 is lower than the voltage of the main output terminal Vo1, so as to prevent the main output voltage from bouncing up.

Similarly, when the multiple sets of output buck converters are turned off, although the second upper arm switch 202 of the second auxiliary buck converter 20 is in a closed state, the second lower arm switch 204 It is an open state, therefore, for the energy stored in the second output capacitor 108 of the second buck converter 20, the path provided by the external operating load of the second auxiliary buck converter 20 (not marked) is released, so that the voltage of the second auxiliary output terminal Vb2 is lower than the voltage of the main output terminal Vo1, so as to prevent the main output voltage from bouncing up.

In short, when the multiple sets of output buck converters are shut down, the control signal pair generated by the abnormal voltage signal generating unit 70 controls the first upper arm switch of the first auxiliary buck converter 10 102 and the first lower arm switch 104 and the second upper arm switch 202 and the second lower arm switch 204 of the second auxiliary buck converter 20, so that the first auxiliary buck converter 10 and the The energy stored in the second auxiliary step-down converter 20 is released through the paths provided by the respective external operating loads, so as to prevent the stored energy from returning to the main step-down converter 80, causing the main output The voltage bounces up.

In summary, the present invention has the following advantages:

1. When the multiple sets of output step-down conversion devices are shut down, the switching elements controlling the auxiliary step-down converters can release the energy stored in the auxiliary step-down converters through the provided path, This prevents the stored energy from being sent back to the main step-down converter, causing the main output voltage to bounce up, so that the multiple sets of output step-down conversion devices can be normally shut down.

2. When the multi-group output step-down conversion device is shut down, controlling the switching elements of the auxiliary step-down converters can prevent the energy stored in the auxiliary step-down converters from being fed back to the main step-down converter converter, causing the main output voltage to bounce up, so as to realize the normal shutdown of the multiple sets of output step-down conversion devices.

Of course, the present invention can also have other various embodiments, and those skilled in the art can make various corresponding changes and deformations according to the present invention without departing from the spirit and essence of the present invention. All changes and deformations should belong to the protection scope of the appended claims of the present invention.

Claims (6)

1. A multi-group output step-down conversion device with shutdown protection, characterized in that it includes a main step-down converter and at least one auxiliary step-down converter to provide multiple sets of output power; wherein the main The step-down converter has a main output terminal to provide a main output voltage relative to the reference ground; the auxiliary step-down converter is electrically connected to the main step-down converter, includes an upper arm switch and a lower arm switch, and has An auxiliary output terminal to provide an auxiliary output voltage relative to the reference ground terminal; the multi-output step-down conversion device further includes: An abnormal voltage signal generating unit is electrically connected to an input terminal of the main step-down converter to generate at least one control signal pair; wherein the control signal pair includes an upper arm control signal and a lower arm control signal; when the multiple sets When the output step-down conversion device is turned off, the upper arm control signal and the lower arm control signal are not at high potential at the same time, so as to respectively control the upper arm switch and the lower arm switch; Thereby, the control signal pair controls the upper arm switch and the lower arm switch of the auxiliary buck converter, so that the energy stored in the auxiliary buck converter passes through the internal path of the auxiliary buck converter Or release through the path provided by the external operating load of the auxiliary step-down converter, so as to prevent the stored energy from returning to the main step-down converter, causing the main output voltage to bounce up. 2. The multi-group output step-down conversion device with shutdown protection according to claim 1, wherein the abnormal voltage signal generating unit compares the voltage of the input terminal of the main step-down converter with a low voltage At a voltage threshold, the upper arm control signal and the lower arm control signal are triggered to be in low potential and high potential respectively, and the upper arm switch is controlled to be open and the lower arm switch to be closed. 3. The multi-group output step-down conversion device with shutdown protection according to claim 1, wherein the abnormal voltage signal generation unit compares the input terminal of the main step-down converter with a voltage low At a voltage threshold, the upper arm control signal and the lower arm control signal are both triggered to be in a low potential state, and the upper arm switch and the lower arm switch are controlled to be open. 4. The multi-group output step-down conversion device with shutdown protection according to claim 1, wherein the abnormal voltage signal generating unit compares the input terminal of the main step-down converter with a voltage low At a voltage threshold, the upper arm control signal and the lower arm control signal are triggered to be in a state of high potential and low potential respectively, and the upper arm switch is controlled to be closed and the lower arm switch to be opened. 5. The multi-output step-down conversion device with shutdown protection according to claim 1, wherein the main output voltage of the main step-down converter is higher than the auxiliary output voltage of the auxiliary step-down converter The output voltage. 6. The multi-output step-down conversion device with shutdown protection according to claim 1, wherein when the multi-output step-down conversion device is not shut down, the upper arm control signal and the lower arm control signal It is a potential complementary pulse width modulation signal.

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