阅读说明：本技术 一种升压拓扑负载短路保护电路 (Boost topology load short-circuit protection circuit ) 是由 张义 薛涛 于 2019-10-10 设计创作，主要内容包括：本发明提供了一种升压拓扑负载短路保护电路,包括：负载、取样电阻、取样电阻、保护芯片、MOS管、CS电阻；MOS管的漏极与负载的负极连接；取样电阻的一端连接MOS管的漏极的一端,另一端接保护芯片的FB脚；取样电阻的一端连接保护芯片的FB脚,另一端连接地；保护芯片的驱动脚OUT与MOS管的栅极连接,保护芯片的CS脚与MOS管的栅极连接,保护芯片的HV脚与负载的正极连接；CS电阻的一端接保护芯片的CS脚,另一端接地。其优点在于升压拓扑的负载可以短路保护,短路故障移除后线路可以继续工作。(The invention provides a boost topology load short-circuit protection circuit, which comprises: the device comprises a load, a sampling resistor, a protection chip, an MOS (metal oxide semiconductor) tube and a CS (circuit switch) resistor; the drain electrode of the MOS tube is connected with the negative electrode of the load; one end of the sampling resistor is connected with one end of the drain electrode of the MOS tube, and the other end of the sampling resistor is connected with an FB pin of the protection chip; one end of the sampling resistor is connected with the FB pin of the protection chip, and the other end of the sampling resistor is connected with the ground; a driving pin OUT of the protection chip is connected with a grid electrode of the MOS tube, a CS pin of the protection chip is connected with the grid electrode of the MOS tube, and an HV pin of the protection chip is connected with the anode of the load; one end of the CS resistor is connected with the CS pin of the protection chip, and the other end of the CS resistor is grounded. The method has the advantages that the load of the boost topology can be protected in a short circuit mode, and the line can continue to work after the short-circuit fault is removed.)

1. A boost topology load short circuit protection circuit is characterized in that: the circuit comprises a load 215, a sampling resistor 212, a sampling resistor 213, a protection chip 214, an MOS tube 216 and a CS resistor 219;

The drain electrode of the MOS tube 216 is connected with the negative electrode of the load;

One end of the sampling resistor 212 is connected to one end of the drain of the MOS tube 216, and the other end is connected to the FB pin of the protection chip 214;

One end of the sampling resistor 213 is connected to the FB pin of the protection chip 214, and the other end is connected to ground;

The driving pin OUT of the protection chip 214 is connected with the gate of the MOS tube 216, the CS pin of the protection chip 214 is connected with the gate of the MOS tube 216, and the HV pin of the protection chip 214 is connected with the anode of the load 215;

One end of the CS resistor 219 is connected to the CS pin of the protection chip, and the other end is grounded.

2. a boost topology load short-circuit protection circuit according to claim 1, characterized in that: the device also comprises an alternating current power supply AC, a rectifier bridge, a boost inductor 206, a boost chip 207, an MOS tube 208, a sampling resistor 209, a boost diode 210 and a capacitor 211;

two input ends of the rectifier bridge are connected with an Alternating Current (AC) power supply; the positive output end of the rectifier bridge is connected with one end of the boost inductor 206, and the negative output end is grounded;

The other end of the boosting inductor 206 is connected with the drain of the MOS tube 208 and the anode of the boosting diode 210;

the grid electrode of the MOS tube 208 is connected with a driving pin OUT of the boosting chip 207, and the source electrode is connected with one end of the sampling resistor 209; the other end of the sampling resistor 209 is grounded;

The cathode of the boost diode 210 is connected with one end of the filter capacitor 211; the other end of the filter capacitor 211 is grounded;

The HV pin of the boost chip 207 is connected with the positive output end of the rectifier bridge;

The anode of load 215 is also connected to the cathode of boost diode 210.

3. A boost topology load short-circuit protection circuit according to claim 2, characterized in that: further comprises a sampling resistor 217 and a sampling resistor 218;

one end of the sampling resistor 207 is connected to the cathode of the boost diode 210, and the other end is connected to the FB pin of the chip 207;

one end of the sampling resistor 208 is connected to the FB pin of the chip 207, and the other end is grounded.

4. A boost topology load short-circuit protection circuit according to claim 2, characterized in that: further comprising a supply capacitor 205;

One end of the power supply capacitor 205 is connected to the Vcc terminal of the boost chip 207, and the other end is grounded.

5. A boost topology load short-circuit protection circuit according to claim 1, characterized in that: the sampling resistor 212, the sampling resistor 213, and the protection chip 214 are integrated into a first integrated chip T1.

6. A boost topology load short-circuit protection circuit according to claim 1, characterized in that: the sampling resistor 212, the sampling resistor 213, the protection chip 214, and the MOS 216 are integrated into a first integrated chip T2.

7. A boost topology load short-circuit protection circuit according to any of claims 1 to 6, characterized by:

When the drain voltage of the MOS 216 rises, the voltage divided by the sampling resistor 212 and the sampling resistor 213 and sent to the FB pin of the protection chip 214 rises synchronously;

when the voltage of the FB pin of the protection chip 214 reaches the protection voltage, the protection chip 214 turns off the driving of the MOS transistor 216;

when the load short circuit is recovered to normal, the voltage of the drain of the MOS 216 drops, the FB pin of the chip 214 drops, and when the voltage drops below the protection voltage, the driving pin OUT of the protection chip 214 drives the MOS 216 to turn on again.

Technical Field

The invention relates to a boost topological load short-circuit protection circuit.

background

Fig. 1 is a conventional boost topology.

As shown in FIG. 1, the input power is rectified by the rectifier diodes 101, 102, 103, 104 to become pulsating direct current, the pulsating direct current is boosted by the boost inductor 106, the boost diode 110, the MOS transistor 108, the sampling resistor 109 and the chip 107 to supply a high voltage to the load 115, and the amplitude of the high voltage is determined by the ratio of the resistors 118 and 117. When the load of the boost circuit is short-circuited, the rectified pulsating direct current high-voltage end is grounded through the inductor 106 and the boost diode 110 to form a loop, and the current in the loop is uncontrolled, so that irreversible damage can be caused to a power supply.

disclosure of Invention

The invention provides a boost topology load short-circuit protection circuit, which is characterized in that a low-voltage end of a load is connected with an MOS tube, a driving MOS and two sampling resistors, so that the boost topology circuit has a protection function when the load is in short circuit.

The invention provides a boost topology load short-circuit protection circuit, which comprises: load 215, sampling resistor 212, sampling resistor 213, protection chip 214, MOS tube 216, CS resistor 219; the drain electrode of the MOS tube 216 is connected with the negative electrode of the load; one end of the sampling resistor 212 is connected to one end of the drain of the MOS tube 216, and the other end is connected to the FB pin of the protection chip 214; one end of the sampling resistor 213 is connected to the FB pin of the protection chip 214, and the other end is connected to ground; the driving pin OUT of the protection chip 214 is connected with the gate of the MOS tube 216, the CS pin of the protection chip 214 is connected with the gate of the MOS tube 216, and the HV pin of the protection chip 214 is connected with the anode of the load 215; one end of the CS resistor 219 is connected to the CS pin of the protection chip, and the other end is grounded.

The invention further provides a boost topology load short-circuit protection circuit, which has the following technical characteristics: the device also comprises an alternating current power supply AC, a rectifier bridge, a boost inductor 206, a boost chip 207, an MOS tube 208, a sampling resistor 209, a boost diode 210 and a capacitor 211; two input ends of the rectifier bridge are connected with an Alternating Current (AC) power supply; the positive output end of the rectifier bridge is connected with one end of the boost inductor 206, and the negative output end is grounded; the other end of the boosting inductor 206 is connected with the drain of the MOS tube 208 and the anode of the boosting diode 210; the grid electrode of the MOS tube 208 is connected with a driving pin OUT of the boosting chip 207, and the source electrode is connected with one end of the sampling resistor 209; the other end of the sampling resistor 209 is grounded; the cathode of the boost diode 210 is connected with one end of the filter capacitor 211; the other end of the filter capacitor 211 is grounded; the HV pin of the boost chip 207 is connected with the positive output end of the rectifier bridge; the anode of load 215 is also connected to the cathode of boost diode 210.

the invention further provides a boost topology load short-circuit protection circuit, which has the following technical characteristics: further comprises a sampling resistor 217 and a sampling resistor 218; one end of the sampling resistor 207 is connected to the cathode of the boost diode 210, and the other end is connected to the FB pin of the chip 207; one end of the sampling resistor 208 is connected to the FB pin of the chip 207, and the other end is grounded.

The invention further provides a boost topology load short-circuit protection circuit, which has the following technical characteristics: further comprising a supply capacitor 205; one end of the power supply capacitor 205 is connected to the Vcc terminal of the boost chip 207, and the other end is grounded.

The invention further provides a boost topology load short-circuit protection circuit, which has the following technical characteristics: the sampling resistor 212, the sampling resistor 213 and the protection chip 214 are integrated into a first integrated chip T1.

the invention further provides a boost topology load short-circuit protection circuit, which has the following technical characteristics: the sampling resistor 212, the sampling resistor 213, the protection chip 214 and the MOS tube 216 are integrated into a first integrated chip T2.

the invention further provides a boost topology load short-circuit protection circuit, which has the following technical characteristics: when the drain voltage of the MOS 216 rises, the voltage divided by the sampling resistor 212 and the sampling resistor 213 and sent to the FB pin of the protection chip 214 rises synchronously; when the voltage of the FB pin of the protection chip 214 reaches the protection voltage, the protection chip 214 turns off the driving of the MOS transistor 216; when the load short circuit is recovered to normal, the voltage of the drain of the MOS 216 drops, the FB pin of the chip 214 drops, and when the voltage drops below the protection voltage, the driving pin OUT of the protection chip 214 drives the MOS 216 to turn on again.

Compared with the traditional boost topology circuit, the boost topology load short-circuit protection circuit provided by the invention can enable a new boost topology circuit to have a load short-circuit protection function.

Drawings

fig. 1 is a conventional boost topology.

fig. 2 is a schematic diagram of a boost topology load short-circuit protection circuit in the first embodiment.

Fig. 3 is a schematic diagram of the boost topology load short-circuit protection circuit in the second embodiment.

Fig. 4 is a schematic diagram of the boost topology load short-circuit protection circuit in the third embodiment.

The specific implementation mode is as follows:

the invention is described in further detail below with reference to the figures and the detailed description.