H-bridge driver circuit layout with temperature sensor

Abstract

According to the H-bridge driving circuit layout with the temperature sensor provided by the utility model, the temperature sensor is placed between the first high-side driving tube and the second high-side driving tube, so that a certain distance exists between the temperature sensor and the low-side driving unit; therefore, the electric leakage influence on the temperature sensor when the low-side driving unit generates the negative voltage is reduced, and the distance between the temperature sensor and the central position of the H-bridge driving circuit is small, so that the temperature sensor can accurately measure the temperature change of the H-bridge driving circuit.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit layout field especially, it relates to a kind of H bridge drive circuit layout with temperature sensor. BACKGROUND

[0002] H bridge drive circuit is a kind of circuit structure for controlling DC motor or certain step motor, it controls the current direction of motor by four switching elements (usually MOSFET or bipolar transistor BJT), to realize the positive and negative rotation, speed regulation, brake etc. of motor function. And, it is widely used in audio power amplification circuit, the temperature of this drive circuit will sharply increase with the increase of power, leading to switching element overheat burnout. Therefore, it is necessary to set a temperature sensor in H bridge drive circuit, i.e. alarm is carried out by temperature sensor when the temperature of switching element reaches certain value, to prevent switching element overheat burnout.

[0003] However, the layout position and isolation mode of temperature sensor in prior art cannot accurately measure the temperature in H bridge drive circuit without affecting temperature sensor. SUMMARY

[0004] The utility model provides a kind of H bridge drive circuit layout with temperature sensor, to accurately measure the temperature change of the H bridge drive circuit on the basis of reducing the leakage influence caused to temperature sensor when negative voltage is generated in low-side drive unit.

[0005] To solve the above technical problems, the utility model provides a kind of H bridge drive circuit layout with temperature sensor, comprising:

[0006] High-side drive unit, the high-side drive unit includes first high-side drive tube and second high-side drive tube, the second high-side drive tube is arranged along the first direction with the first high-side drive tube, and there is distance between the first high-side drive tube and the second high-side drive tube;

[0007] Low-side drive unit, the low-side drive unit includes first low-side drive tube and second low-side drive tube, the second low-side drive tube is arranged along the first direction with the first low-side drive tube, and there is distance between the first low-side drive tube and the second low-side drive tube, the first low-side drive tube is arranged along the second direction with the first high-side drive tube, the second low-side drive tube is arranged along the second direction with the second high-side drive tube, and the first direction is perpendicular to the second direction;

[0008] Temperature sensor, the temperature sensor is located between the first high-side drive tube and the second high-side drive tube, and there is distance between the temperature sensor and the first high-side drive tube and the second high-side drive tube.

[0009] Optionally, the temperature sensor is an NPN transistor, and a collector of the NPN transistor is connected to the first power supply voltage.

[0010] Optionally, the circuit further comprises a first NBL isolation layer between the high-side driving unit and the low-side driving unit, the first NBL isolation layer is connected to a second power supply voltage, and distances exist between the first NBL isolation layer and the high-side driving unit and the low-side driving unit.

[0011] Optionally, the circuit further comprises a second NBL isolation layer between the first low-side driving transistor and the second low-side driving transistor, one end of the second NBL isolation layer is connected to the first NBL isolation layer, and the other end of the second NBL isolation layer does not exceed a boundary of the low-side driving unit away from the first NBL isolation layer, and distances exist between the second NBL isolation layer and the first low-side driving transistor and the second low-side driving transistor.

[0012] Optionally, the first high-side driving transistor, the second high-side driving transistor, the first low-side driving transistor, and the second low-side driving transistor are all N-type lateral diffused metal oxide semiconductor devices.

[0013] Optionally, the first low-side driving transistor is surrounded by a first NBL isolation ring, the first NBL isolation ring is located at a periphery of the first low-side driving transistor, and a drain terminal of the first low-side driving transistor is connected to the first NBL isolation ring; and the second low-side driving transistor is surrounded by a second NBL isolation ring, the second NBL isolation ring is located at a periphery of the second low-side driving transistor, and a drain terminal of the second low-side driving transistor is connected to the second NBL isolation ring.

[0014] Optionally, the first high-side driving transistor is surrounded by a third NBL isolation ring, the third NBL isolation ring is located at a periphery of the first high-side driving transistor, a drain terminal of the first high-side driving transistor is connected to the third NBL isolation ring, and the third NBL isolation ring is connected to the second power supply voltage; and the second high-side driving transistor is surrounded by a fourth NBL isolation ring, the fourth NBL isolation ring is located at a periphery of the second high-side driving transistor, a drain terminal of the second high-side driving transistor is connected to the fourth NBL isolation ring, and the fourth NBL isolation ring is connected to the second power supply voltage.

[0015] Optionally, the first NBL isolation layer, the second NBL isolation layer, the first NBL isolation ring, the second NBL isolation ring, the third NBL isolation ring, and the fourth NBL isolation ring are all implemented based on a 0.18 BCD process platform.

[0016] Optionally, the high-side driving unit, the low-side driving unit and the temperature sensor are located in the same chip, and the low-side driving unit is located at the edge of the chip.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] The H-bridge driving circuit layout with the temperature sensor provided by the utility model places the temperature sensor between the first high-side driving tube and the second high-side driving tube, so that the temperature sensor is kept a certain distance from the low-side driving unit, thereby reducing the leakage influence of the negative voltage generated by the low-side driving unit on the temperature sensor, and the temperature sensor is kept a small distance from the center of the H-bridge driving circuit, thereby enabling the temperature sensor to more accurately measure the temperature change of the H-bridge driving circuit.

[0019] Further, the temperature sensor is an NPN triode, and the collector of the NPN triode is connected to the first power supply voltage, so that the influence of the negative voltage at the drain end of the first low-side driving tube and the second low-side driving tube on the base and the emitter of the NPN triode can be isolated.

[0020] Further, a first NBL isolation layer is arranged between the high-side driving unit and the low-side driving unit, the first NBL isolation layer is connected to the second power supply voltage, so that the negative voltage generated by the low-side driving unit can be isolated, thereby reducing the leakage or latch effect between the high-side driving unit and the low-side driving unit. A second NBL isolation layer is arranged between the first low-side driving tube and the second low-side driving tube, so that the negative voltage at the drain end of the first low-side driving tube and the negative voltage at the drain end of the second low-side driving tube can be isolated, thereby reducing the leakage or latch effect between the first low-side driving tube and the second low-side driving tube, and one end of the second NBL isolation layer is connected to the first NBL isolation layer, so that the first low-side driving tube and the second high-side driving tube and the second low-side driving tube and the first high-side driving tube can be better isolated. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of an H-bridge driving circuit layout with a temperature sensor;

[0022] Figure 2 is a schematic diagram of another H-bridge driving circuit layout with a temperature sensor;

[0023] Figure 3 is a schematic diagram of a circuit structure of an H-bridge driving circuit provided by an embodiment of the utility model;

[0024] Figure 4 is a schematic diagram of an H-bridge driving circuit layout with a temperature sensor provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0025] As described in the background, the layout position and isolation method of the temperature sensor in the prior art cannot accurately measure the temperature in the H-bridge driving circuit without affecting the chip.

[0026] The following is an example of two H-bridge driving circuit temperature sensor layout diagrams, which analyzes in detail the specific reasons why the layout position and isolation method of the following two temperature sensors cannot accurately measure the temperature in the H-bridge driving circuit without affecting the temperature sensor.

[0027] Figure 1 is an H-bridge driving circuit layout diagram with a temperature sensor.

[0028] For ease of understanding, Figure 1 The first high-side drive tube, the second high-side drive tube, the first low-side drive tube, the second low-side drive tube, the temperature sensor Q1, and the first NBL protection layer 1 are schematically shown, and the first high-side drive tube and the second high-side drive tube and the first low-side drive tube and the second low-side drive tube are located on both sides of the first NBL protection layer 1, and the NBL protection ring of the first NBL protection layer 1, the first low-side drive tube and the second low-side drive tube are connected to the ground.

[0029] Please refer to Figure 1 The temperature sensor Q1 is located on the side of the first NBL protection layer 1 close to the first high-side drive tube and the second high-side drive tube, and close to the center position between the first high-side drive tube, the second high-side drive tube, the first low-side drive tube and the second low-side drive tube. Since the driving circuit is cross-operated, i.e. the first low-side drive tube and the second high-side drive tube operate at the same time, or the second low-side drive tube and the first high-side drive tube operate at the same time, the temperature at the center position is the highest. When the power of the driving circuit is large, the first NBL protection layer 1 connected to the ground cannot isolate the negative pressure generated by the first low-side drive tube and the second low-side drive tube, so that the temperature sensor Q1 close to the first NBL protection layer 1 and the four drive tubes produce a latch effect, and then burn the chip.

[0030] Figure 2 is another H-bridge driving circuit layout diagram with a temperature sensor.

[0031] For ease of understanding, Figure 2The first high-side drive tube, the second high-side drive tube, the first low-side drive tube, the second low-side drive tube, the temperature sensor, the second NBL protective layer 2 and the third NBL protective layer 3 are schematically shown, the first high-side drive tube and the second high-side drive tube and the first low-side drive tube and the second low-side drive tube are respectively located on two sides of the second NBL protective layer 2, the third NBL protective layer 3 is used for isolating the first high-side drive tube and the second high-side drive tube from the temperature sensor, and the third NBL protective layer 3 is connected with a power supply voltage.

[0032] Please refer to Figure 2 The third NBL protective layer 3 is arranged between the temperature sensor Q2 and the four drive tubes to isolate the temperature sensor Q2, so that the temperature sensor Q2 is difficult to be affected by the negative pressure generated by the first low-side drive tube and the second low-side drive tube, however, since the distance between the temperature sensor Q2 and the center position between the four drive tubes is far, the temperature measured by the temperature sensor Q2 is lower than the actual temperature of the drive circuit, and when the temperature of the drive circuit reaches a critical value, the temperature sensor Q2 will not issue an alarm due to the measured temperature being lower than the actual temperature, and the chip will eventually be burned due to overheating.

[0033] Therefore, the utility model provides a kind of H bridge drive circuit layout with temperature sensor, comprising:

[0034] High-side drive unit, the high-side drive unit includes first high-side drive tube and second high-side drive tube, the second high-side drive tube is arranged along first direction with the first high-side drive tube, and there is distance between the first high-side drive tube and the second high-side drive tube;Low-side drive unit, the low-side drive unit includes first low-side drive tube and second low-side drive tube, the second low-side drive tube is arranged along first direction with the first low-side drive tube, and there is distance between the first low-side drive tube and the second low-side drive tube, the first low-side drive tube is arranged along second direction with the first high-side drive tube, the second low-side drive tube is arranged along second direction with the second high-side drive tube, and the first direction is perpendicular to the second direction;Temperature sensor, the temperature sensor is located between the first high-side drive tube and the second high-side drive tube, and there is distance between the temperature sensor and the first high-side drive tube and the second high-side drive tube.

[0035] By placing the temperature sensor between the first high-side drive tube and the second high-side drive tube, the temperature sensor is kept a certain distance from the low-side drive unit, thereby reducing the leakage effect on the temperature sensor when negative voltage is generated in the low-side drive unit, and the temperature sensor is kept a small distance from the center position of the H bridge drive circuit, thereby enabling the temperature sensor to accurately measure the temperature change of the H bridge drive circuit.

[0036] In order to make the above-mentioned purpose, characteristics and beneficial effects of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0037] In the embodiment, please refer to Figure 4 It is a good choice to place the temperature sensor QM at a relatively central position between the first high-side drive tube MPH and the second high-side drive tube MNH, so that the distance between the temperature sensor QM and the central position of the H-bridge drive circuit and the distance between the temperature sensor QM and the low-side drive unit can be balanced, thereby accurately measuring the temperature change of the H-bridge drive circuit on the basis of reducing the leakage influence on the temperature sensor QM when the low-side drive unit generates a negative voltage.

[0038] In the embodiment, the first high-side drive tube MPH, the second high-side drive tube MNH, the first low-side drive tube MPL and the second low-side drive tube MNL are all N-type lateral diffusion metal oxide semiconductor devices.

[0039] In the embodiment, please refer to Figure 3 The drain terminal of the first high-side drive tube MPH and the drain terminal of the second high-side drive tube MNH are connected together and connected to the second power supply voltage PVDD, the source terminal of the first high-side drive tube MPH is connected to the drain terminal of the first low-side drive tube MPL and connected to one end of the load to serve as the first output terminal OUTP, the source terminal of the second high-side drive tube MNH is connected to the drain terminal of the second low-side drive tube MNL and connected to the other end of the load to serve as the second output terminal OUTN, and the source terminal of the first low-side drive tube MPL and the source terminal of the second low-side drive tube MNL are connected together and connected to the ground. The second power supply voltage PVDD is the highest voltage in the chip. In the H-bridge drive circuit, the four drive tubes are cross-operated to drive the load, that is, the first high-side drive tube MPH and the second low-side drive tube MNL are simultaneously turned on as a group, the second high-side drive tube MNH and the first low-side drive tube MPL are simultaneously turned on as a group, and the drive tubes of the two groups are alternately turned on.

[0040] In the embodiment, the high-side drive unit, the low-side drive unit and the temperature sensor QM are all located in the same chip, and the low-side drive unit is located at the edge position of the chip. Specifically, since the low-side drive unit generates a large amount of heat when working by passing a large current, arranging the low-side drive unit at the edge position of the chip can help heat dissipation, thereby improving the stability and reliability of the circuit.

[0041] In the embodiment, please refer to Figure 4The temperature sensor QM is an NPN triode, and the collector of the NPN triode is connected to the first power supply voltage AVDD. The NPN triode is a BJT triode. Due to the limitation of the device performance of the NPN triode, the first power supply voltage AVDD is less than the second power supply voltage PVDD. For example, the first power supply voltage AVDD can be 5V. In addition, the connection of the collector of the NPN triode to the first power supply voltage AVDD can isolate the negative voltage generated at the drain end of the low-side driving unit from affecting the base and emitter of the NPN triode.

[0042] In the embodiment, the layout of the H-bridge driving circuit with the temperature sensor further includes a first NBL isolation layer 11 located between the high-side driving unit and the low-side driving unit. The first NBL isolation layer 11 is connected to the second power supply voltage PVDD, and there is a distance between the first NBL isolation layer 11 and the high-side driving unit and the low-side driving unit. The first NBL isolation layer 11 is arranged between the high-side driving unit and the low-side driving unit, and is connected to the second power supply voltage PVDD, so as to isolate the negative voltage generated at the drain end of the low-side driving unit, thereby reducing the risk of leakage or latch-up effect between the high-side driving unit and the low-side driving unit.

[0043] In the embodiment, the layout of the H-bridge driving circuit with the temperature sensor further includes a second NBL isolation layer 22 located between the first low-side driving transistor MPL and the second low-side driving transistor MNL. One end of the second NBL isolation layer 22 is connected to the first NBL isolation layer 11, and the other end of the second NBL isolation layer 22 does not exceed the boundary of the low-side driving unit away from the first NBL isolation layer 11. There is a distance between the second NBL isolation layer 22 and the first low-side driving transistor MPL and the second low-side driving transistor MNL. The second NBL isolation layer 22 is arranged between the first low-side driving transistor MPL and the second low-side driving transistor MNL, so as to isolate the negative voltage at the drain end of the first low-side driving transistor MPL from the negative voltage at the drain end of the second low-side driving transistor MNL, thereby reducing the risk of leakage or latch-up effect between the first low-side driving transistor MPL and the second low-side driving transistor MNL. Further, since more charges are likely to accumulate at the four corners of the four driving transistors close to the center of the H-bridge driving circuit, leakage is more likely to occur at the four corners than at other places. Therefore, the connection of one end of the second NBL isolation layer 22 to the first NBL isolation layer 11 can better isolate the first low-side driving transistor MPL from the second high-side driving transistor MNH and the second low-side driving transistor MNL from the first high-side driving transistor MPH.

[0044] In the embodiment, the first low-side drive tube MPL is surrounded by the first NBL isolation ring 100, and the first NBL isolation ring 100 is located at the periphery of the first low-side drive tube MPL and is connected to the drain terminal of the first low-side drive tube MPL; the second low-side drive tube MNL is surrounded by the second NBL isolation ring 200, and the second NBL isolation ring 200 is located at the periphery of the second low-side drive tube MNL and is connected to the drain terminal of the second low-side drive tube MNL. The first NBL isolation ring 100 and the second NBL isolation ring 200 are NBL protection rings of the first low-side drive tube MPL and the second low-side drive tube MNL, and due to the limitation of the device itself, the first NBL isolation ring 100 and the second NBL isolation ring 200 can only be connected to the first low-side drive tube MPL and the second low-side drive tube MNL, respectively.

[0045] In the embodiment, the first high-side drive tube MPH is surrounded by the third NBL isolation ring 300, and the third NBL isolation ring 300 is located at the periphery of the first high-side drive tube MPH and is connected to the drain terminal of the first high-side drive tube MPH and accessed to the second power supply voltage PVDD; the second high-side drive tube MNH is surrounded by the fourth NBL isolation ring 400, and the fourth NBL isolation ring 400 is located at the periphery of the second high-side drive tube MNH and is connected to the drain terminal of the second high-side drive tube MNH and accessed to the second power supply voltage PVDD. The third NBL isolation ring 300 and the fourth NBL isolation ring 400 are NBL protection rings of the first high-side drive tube MPH and the second high-side drive tube MNH, and due to the limitation of the device itself, the third NBL isolation ring 300 and the fourth NBL isolation ring 400 can only be connected to the first high-side drive tube MPH and the second high-side drive tube MNH, respectively.

[0046] In the embodiment, the first NBL isolation layer 11, the second NBL isolation layer 22, the first NBL isolation ring 100, the second NBL isolation ring 200, the third NBL isolation ring 300 and the fourth NBL isolation ring 400 are realized based on a 0.18 BCD process platform.

[0047] In summary, in the H-bridge drive circuit layout with the temperature sensor provided by the utility model, the temperature sensor QM is placed between the first high-side drive tube MPH and the second high-side drive tube MNH, so that the temperature sensor QM is kept a certain distance from the low-side drive unit, thereby reducing the leakage influence on the temperature sensor QM when a negative voltage is generated in the low-side drive unit, and the temperature sensor QM is kept a small distance from the center position of the H-bridge drive circuit, thereby enabling the temperature sensor QM to more accurately measure the temperature change of the H-bridge drive circuit.

[0048] Further, the temperature sensor QM is an NPN triode, and the collector of the NPN triode is connected to the first power supply voltage AVDD, so that the influence of the negative voltage at the drain ends of the first low-side drive transistor MPL and the second low-side drive transistor MNL on the base and the emitter of the NPN triode can be isolated.

[0049] Further, the first NBL isolation layer 11 is arranged between the high-side drive unit and the low-side drive unit, and the first NBL isolation layer 11 is connected to the second power supply voltage PVDD, so that the negative voltage generated by the low-side drive unit can be isolated, thereby reducing the risk of leakage or latch-up effect between the high-side drive unit and the low-side drive unit. The second NBL isolation layer 22 is arranged between the first low-side drive transistor MPL and the second low-side drive transistor MNL, so that the negative voltage at the drain end of the first low-side drive transistor MPL and the negative voltage at the drain end of the second low-side drive transistor MNL can be isolated, thereby reducing the risk of leakage or latch-up effect between the first low-side drive transistor MPL and the second low-side drive transistor MNL. The second NBL isolation layer 22 is connected to the first NBL isolation layer 11, so that the first low-side drive transistor MPL and the second high-side drive transistor MNH, and the second low-side drive transistor MNL and the first high-side drive transistor MPH can be better isolated.

[0050] Although the utility model discloses as above, the utility model is not limited to this. Any person skilled in the art, without departing from the spirit and scope of the utility model, can make various changes and modifications, therefore the protection scope of the utility model should be the range limited by claim.

Claims

1. An H-bridge drive circuit topology with temperature sensor, characterized in that, The application relates to a high-side driving unit and a low-side driving unit. The high-side driving unit comprises a first high-side driving tube and a second high-side driving tube, the second high-side driving tube is arranged along a first direction with the first high-side driving tube, and a distance exists between the first high-side driving tube and the second high-side driving tube. The low-side driving unit comprises a first low-side driving tube and a second low-side driving tube, the second low-side driving tube is arranged along a first direction with the first low-side driving tube, a distance exists between the first low-side driving tube and the second low-side driving tube, the first low-side driving tube is arranged along a second direction with the first high-side driving tube, the second low-side driving tube is arranged along the second direction with the second high-side driving tube, and the first direction is perpendicular to the second direction. A temperature sensor is arranged between the first high-side driving tube and the second high-side driving tube, and a distance exists between the temperature sensor and the first high-side driving tube and the second high-side driving tube.

2. The H-bridge drive circuit layout with temperature sensor of claim 1, wherein, The temperature sensor is an NPN triode, and the collector of the NPN triode is connected to a first power supply voltage.

3. The H-bridge drive circuit layout with temperature sensor of claim 1, wherein, The application further comprises: A first NBL isolation layer is arranged between the high-side driving unit and the low-side driving unit, the first NBL isolation layer is connected to a second power supply voltage, and a distance exists between the first NBL isolation layer and the high-side driving unit and the low-side driving unit.

4. The H-bridge drive circuit layout with temperature sensor of claim 3, wherein, The application further comprises: A second NBL isolation layer is arranged between the first low-side driving tube and the second low-side driving tube, one end of the second NBL isolation layer is connected to the first NBL isolation layer, the other end of the second NBL isolation layer does not exceed the boundary of the low-side driving unit away from the first NBL isolation layer, and a distance exists between the second NBL isolation layer and the first low-side driving tube and the second low-side driving tube.

5. The H-bridge drive circuit layout with temperature sensor of claim 4, wherein, The first high-side driving tube, the second high-side driving tube, the first low-side driving tube and the second low-side driving tube are all N-type lateral diffusion metal oxide semiconductor devices.

6. The H-bridge drive circuit layout with temperature sensor of claim 5, wherein, The first low-side driving tube is surrounded by a first NBL isolation ring, the first NBL isolation ring is arranged at the periphery of the first low-side driving tube, and the first NBL isolation ring is connected to the drain end of the first low-side driving tube; the second low-side driving tube is surrounded by a second NBL isolation ring, the second NBL isolation ring is arranged at the periphery of the second low-side driving tube, and the second NBL isolation ring is connected to the drain end of the second low-side driving tube.

7. The H-bridge drive circuit layout with temperature sensor of claim 6, wherein, The first high-side driving tube is surrounded by a third NBL isolation ring, the third NBL isolation ring is arranged at the periphery of the first high-side driving tube, the third NBL isolation ring is connected to the drain end of the first high-side driving tube, and the third NBL isolation ring is connected to the second power supply voltage; the second high-side driving tube is surrounded by a fourth NBL isolation ring, the fourth NBL isolation ring is arranged at the periphery of the second high-side driving tube, the fourth NBL isolation ring is connected to the drain end of the second high-side driving tube, and the fourth NBL isolation ring is connected to the second power supply voltage.

8. The H-bridge drive circuit layout with temperature sensor of claim 7, wherein, The first NBL isolation layer, the second NBL isolation layer, the first NBL isolation ring, the second NBL isolation ring, the third NBL isolation ring and the fourth NBL isolation ring are realized based on a 0.18 BCD process platform.

9. The H-bridge driver circuit layout with temperature sensor of claim 1, wherein, The high-side driving unit, the low-side driving unit and the temperature sensor are located in the same chip, and the low-side driving unit is located at an edge position of the chip.

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