A negative voltage converter and semiconductor chip

Abstract

The embodiment of the present application provides a negative voltage converter and a semiconductor chip. The negative voltage converter comprises a main control circuit, an auxiliary control circuit, a first bootstrap capacitor and a voltage conversion circuit, the control end of the main control circuit and the first control end of the auxiliary control circuit are electrically connected with a state driving signal, the first end of the main control circuit is electrically connected with the first end of the auxiliary control circuit and the first control end of the voltage conversion circuit through the first bootstrap capacitor, the second end of the auxiliary control circuit is electrically connected with an input voltage, the second end of the main control circuit is electrically connected with the second control end of the voltage conversion circuit, the third end of the main control circuit is electrically connected with the input voltage, the first end of the voltage conversion circuit is electrically connected with the input voltage, the second end of the voltage conversion circuit is grounded, and the third end of the voltage conversion circuit is electrically connected with a voltage output end. The negative voltage converter can adopt a smaller bootstrap capacitor, the area occupied by the bootstrap capacitor can be reduced, and thus the area occupied by the negative voltage converter can be reduced.

Description

Technical Field

[0001] This application relates to the field of negative voltage conversion technology, and more particularly to a negative voltage converter and a semiconductor chip. Background Technology

[0002] A negative voltage converter can convert an input voltage into a negative output voltage. The input voltage typically comes from a single lithium battery, with the voltage of the battery usually around 4V. The output voltage range is -1V to -6V. A negative voltage converter includes a bootstrap capacitor and a driver transistor. When the bootstrap capacitor discharges, it provides a drive voltage to the driver transistor. The magnitude of the drive voltage depends on the ratio of the bootstrap capacitor to the gate capacitance Cg of the driver transistor.

[0003] Existing technologies typically employ bootstrap capacitors with large capacitance values ​​to increase the drive voltage of the driver transistor and ensure its full conduction. However, larger bootstrap capacitors occupy a larger area, resulting in a larger area occupied by the negative voltage converter. Summary of the Invention

[0004] In view of the above problems, embodiments of this application provide a negative voltage converter and a semiconductor chip that can use a smaller bootstrap capacitor, thereby reducing the area occupied by the bootstrap capacitor and thus reducing the area occupied by the negative voltage converter, which is beneficial to the miniaturization of the device.

[0005] In a first aspect, embodiments of this application provide a negative voltage converter, including: a main control circuit, an auxiliary control circuit, a first bootstrap capacitor, and a voltage conversion circuit; The control terminal of the main control circuit and the first control terminal of the auxiliary control circuit are both electrically connected to the state drive signal. The first terminal of the main control circuit is electrically connected to the first plate of the first bootstrap capacitor. The second plate of the first bootstrap capacitor and the first terminal of the auxiliary control circuit are both electrically connected to the first control terminal of the voltage conversion circuit. The second terminal of the auxiliary control circuit is electrically connected to the input voltage. The second terminal of the main control circuit is electrically connected to the second control terminal of the voltage conversion circuit. The third terminal of the main control circuit is electrically connected to the input voltage. The first terminal of the voltage conversion circuit is electrically connected to the voltage input terminal. The voltage input terminal is externally connected to the input voltage. The second terminal of the voltage conversion circuit is grounded. The third terminal of the voltage conversion circuit is electrically connected to the voltage output terminal. The main control circuit is used to control the first bootstrap capacitor to provide a sub-control voltage to the first control terminal of the voltage conversion circuit under the action of the first state drive signal. The auxiliary control circuit is used to provide the input voltage to the first control terminal of the voltage conversion circuit under the action of the first state drive signal; The voltage conversion circuit is used to convert the input voltage into an output voltage under the action of a control voltage; wherein the control voltage is the sum of the input voltage and the sub-control voltage, and the output voltage is a negative voltage.

[0006] In some embodiments, the auxiliary control circuit includes a first switching transistor and a second switching transistor; The control terminal of the first switch is electrically connected to the state drive signal, the first terminal of the first switch is electrically connected to the input voltage, the second terminal of the first switch is electrically connected to the first terminal of the second switch, the second terminal of the second switch is electrically connected to the first control terminal of the voltage conversion circuit, and the control terminal of the second switch is electrically connected to the clamping voltage.

[0007] In some embodiments, the negative voltage converter further includes a second bootstrap capacitor; The first plate of the second bootstrap capacitor is electrically connected to the first plate of the first bootstrap capacitor, the second plate of the second bootstrap capacitor is electrically connected to the second control terminal of the auxiliary control circuit, the third terminal of the auxiliary control circuit is electrically connected to the voltage output terminal, and the fourth terminal of the main control circuit is grounded. The auxiliary control circuit is also used to provide the output voltage to the first control terminal of the voltage conversion circuit under the action of the second state drive signal; The voltage conversion circuit is also used to store the electrical energy provided by the input voltage under the action of the output voltage.

[0008] In some embodiments, the auxiliary control circuit further includes an inverter, a third switch, a fourth switch, a fifth switch, and a sixth switch; The input terminal of the inverter is electrically connected to the state drive signal, the output terminal of the inverter is electrically connected to the control terminal of the third switch, the first terminal of the third switch is electrically connected to the input voltage, the second terminal of the third switch is electrically connected to the first terminal of the fourth switch, the control terminal of the fourth switch is electrically connected to the clamping voltage, and the second terminal of the fourth switch is electrically connected to the control terminal of the fifth switch and the first terminal of the sixth switch. The first terminal of the fifth switch is electrically connected to the first control terminal of the voltage conversion circuit, the second terminals of the fifth switch and the sixth switch are both electrically connected to the voltage output terminal, and the control terminal of the sixth switch is electrically connected to the second plate of the second bootstrap capacitor.

[0009] In some embodiments, the auxiliary control circuit further includes: a seventh switching transistor; The first terminal of the seventh switch is electrically connected to the second plate of the second bootstrap capacitor, the second terminal of the seventh switch is electrically connected to the voltage output terminal, and the control terminal of the seventh switch is electrically connected to the control terminal of the fifth switch.

[0010] In some embodiments, the negative voltage converter further includes: an eighth switching transistor; The second plate of the first bootstrap capacitor is electrically connected to the first terminal of the eighth switching transistor, and the second terminal of the eighth switching transistor is electrically connected to the first control terminal of the voltage conversion circuit. The eighth switch is used to control the disconnection between the first control terminal of the voltage conversion circuit and the second plate of the first bootstrap capacitor.

[0011] In some embodiments, the negative voltage converter further includes: a clamping circuit; The clamping circuit includes a current source, a clamping switch transistor, and a capacitor. The current source is electrically connected to the input voltage. The output terminal of the current source is electrically connected to the negative terminal of the clamping switch transistor, the first plate of the capacitor, and the control terminal of the second switch transistor. The positive terminal of the clamping switch transistor and the second plate of the capacitor are both electrically connected to the voltage output terminal.

[0012] In some embodiments, the voltage conversion circuit includes: an inductor, an output capacitor, a ninth switch, and a tenth switch; The first terminal of the ninth switch is electrically connected to the input voltage, the control terminal of the ninth switch is electrically connected to the second terminal of the main control circuit, the second terminal of the ninth switch is electrically connected to the first terminal of the inductor and the first terminal of the tenth switch, the control terminal of the tenth switch is electrically connected to the second plate of the first bootstrap capacitor, the second terminal of the tenth switch and the first plate of the output capacitor are both electrically connected to the voltage output terminal, and the second plate of the output capacitor and the second terminal of the inductor are grounded.

[0013] In some embodiments, the main control circuit includes: an eleventh switch, a twelfth switch, a thirteenth switch, and a fourteenth switch; The control terminals of the eleventh switch, the twelfth switch, the thirteenth switch, and the fourteenth switch are all electrically connected to the state drive signal. The first terminal of the eleventh switch is electrically connected to the input voltage. The second terminal of the eleventh switch is electrically connected to the first terminal of the twelfth switch and the second control terminal of the voltage conversion circuit. The second terminal of the twelfth switch is grounded. The first terminal of the thirteenth switch is electrically connected to the input voltage, the second terminal of the thirteenth switch is electrically connected to the first terminal of the fourteenth switch and the first plate of the first bootstrap capacitor, and the second terminal of the fourteenth switch is grounded.

[0014] In some embodiments, under the action of the first state drive signal, both the first switch and the second switch are turned on, while the third switch is turned off. Under the action of the second state drive signal, the third, fourth and fifth switches are all turned on, while the first and sixth switches are all turned off.

[0015] Secondly, embodiments of this application provide a semiconductor chip, including: any of the negative voltage converters provided in the first aspect.

[0016] In the technical solution of this application embodiment, the negative voltage converter includes: a main control circuit, an auxiliary control circuit, a first bootstrap capacitor, and a voltage conversion circuit. The control terminal of the main control circuit and the first control terminal of the auxiliary control circuit are both electrically connected to a state drive signal. The first terminal of the main control circuit is electrically connected to the first plate of the first bootstrap capacitor. The second plate of the first bootstrap capacitor and the first terminal of the auxiliary control circuit are both electrically connected to the first control terminal of the voltage conversion circuit. The second terminal of the auxiliary control circuit is electrically connected to the input voltage. The second terminal of the main control circuit is electrically connected to the second control terminal of the voltage conversion circuit. The third terminal of the main control circuit is electrically connected to the input voltage. The first terminal of the voltage conversion circuit is electrically connected to the voltage input terminal, which is externally connected to the input voltage. The second terminal of the voltage conversion circuit is grounded. The third terminal of the voltage conversion circuit is electrically connected to the voltage output terminal. Through the main control circuit... Under the action of the first state drive signal, the first bootstrap capacitor can be controlled to provide a sub-control voltage to the first control terminal of the voltage conversion circuit; the auxiliary control circuit can provide an input voltage to the first control terminal of the voltage conversion circuit under the action of the first state drive signal; the voltage conversion circuit can convert the input voltage into an output voltage under the action of the control voltage, wherein the control voltage is the sum of the input voltage and the sub-control voltage, and the output voltage is a negative voltage. Thus, under the action of the first state drive signal, the first bootstrap capacitor and the input voltage jointly provide a control voltage to the first control terminal of the voltage conversion circuit, which can reduce the voltage provided by the first bootstrap capacitor. In this way, a bootstrap capacitor with a smaller capacitance value can be used, which can reduce the area occupied by the bootstrap capacitor, thereby reducing the area occupied by the negative voltage converter, which is conducive to the miniaturization of the device.

[0017] The above description is merely an overview of the technical solutions of the embodiments of this application. In order to better understand the technical means of the embodiments of this application and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of this application more obvious and understandable, specific implementation methods of this application are described below. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a negative voltage converter provided in an embodiment of this application; Figure 2 This is a schematic diagram of another negative voltage converter provided in an embodiment of this application; Figure 3A An equivalent circuit diagram provided for an embodiment of this application; Figure 3B This is another equivalent circuit diagram provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of another negative voltage converter provided in the embodiments of this application; Figure 5 This is a schematic diagram of a clamping circuit provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of another negative voltage converter provided in the embodiments of this application; Figure 7 This is a schematic diagram of the structure of another negative voltage converter provided in the embodiments of this application; Figure 8 This is a schematic diagram of the structure of another negative voltage converter provided in the embodiments of this application; Figure 9A for Figure 8 The diagram shows a schematic of an equivalent circuit for a negative voltage converter. Figure 9B for Figure 8 The diagram shows another equivalent circuit of the negative voltage converter. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims and drawings of this application are intended to cover non-exclusive inclusion.

[0022] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] Furthermore, the terms "first," "second," etc., in the specification and claims of this application or in the aforementioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0024] In the description of this application, unless otherwise expressly specified and limited, the terms "connected" and "connected" shall be interpreted broadly. For example, "connected" or "connected" in circuit structure can refer not only to physical connection, but also to electrical connection or signal connection. For example, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate element, as long as the circuit is connected. It can also refer to the internal connection of two elements. Signal connection can refer not only to signal connection through circuit, but also to signal connection through a medium, such as radio waves.

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0026] Figure 1 This is a schematic diagram of a negative voltage converter provided in an embodiment of this application, as shown below. Figure 1 As shown, the negative voltage converter 100 includes: a main control circuit 110, an auxiliary control circuit 120, a first bootstrap capacitor C1, and a voltage conversion circuit 130.

[0027] In this circuit, the control terminal of the main control circuit 110 and the first control terminal of the auxiliary control circuit 120 are both electrically connected to the state drive signal PWM. The first terminal of the main control circuit 110 is electrically connected to the first plate of the first bootstrap capacitor C1. The second plate of the first bootstrap capacitor C1 and the first terminal of the auxiliary control circuit 120 are both electrically connected to the first control terminal of the voltage conversion circuit 130. The second terminal of the auxiliary control circuit 120 is electrically connected to the input voltage Vin. The second terminal of the main control circuit 110 is electrically connected to the second control terminal of the voltage conversion circuit 130. The third terminal of the main control circuit 110 is electrically connected to the input voltage Vin. The first terminal of the voltage conversion circuit 130 is electrically connected to the voltage input terminal IN. The voltage input terminal IN is externally connected to the input voltage Vin. The second terminal of the voltage conversion circuit 130 is grounded. The third terminal of the voltage conversion circuit 130 is electrically connected to the voltage output terminal OUT.

[0028] The main control circuit 110, under the action of the first state drive signal, controls the first bootstrap capacitor C1 to provide a sub-control voltage V' to the first control terminal of the voltage conversion circuit 130. The auxiliary control circuit 120, under the action of the first state drive signal, provides an input voltage Vin to the first control terminal of the voltage conversion circuit 130. The voltage conversion circuit 130, under the action of the control voltage V, converts the input voltage Vin into an output voltage Vout; wherein the control voltage V is the sum of the input voltage Vin and the sub-control voltage V', and the output voltage Vout is a negative voltage.

[0029] For example, Figure 2 This is a schematic diagram of another negative voltage converter provided in an embodiment of this application. Figure 2 for Figure 1 Based on the embodiment shown, the voltage conversion circuit 130 includes: an inductor L, an output capacitor Cout, a ninth switch Q9, and a tenth switch Q10.

[0030] Specifically, the first terminal of the ninth switch Q9 is electrically connected to the input voltage Vin, the control terminal of the ninth switch Q9 is electrically connected to the second output terminal of the main control circuit 110, the second terminal of the ninth switch Q9 is electrically connected to the first terminal of the inductor L and the first terminal of the tenth switch Q10, the control terminal of the tenth switch Q10 is electrically connected to the second plate of the first bootstrap capacitor C1, the second terminal of the tenth switch Q10 and the first plate of the output capacitor Cout are both electrically connected to the voltage output terminal OUT, and the second plate of the output capacitor Cout and the second terminal of the inductor L are grounded.

[0031] like Figure 2As shown, the first control terminal of the voltage conversion circuit 130 is the control terminal of the tenth switch Q10. The control terminal of the tenth switch Q10 is electrically connected to the second plate of the first bootstrap capacitor C1, thus the first control terminal of the voltage conversion circuit 130 is electrically connected to the second plate of the first bootstrap capacitor C1. The second control terminal of the voltage conversion circuit 130 is the control terminal of the ninth switch Q9. The control terminal of the ninth switch Q9 is electrically connected to the second terminal of the main control circuit 110, thus the second control terminal of the voltage conversion circuit 130 is electrically connected to the second terminal of the main control circuit 110. The first terminal of the voltage conversion circuit 130 is the first terminal of the ninth switch Q9. The first terminal of the ninth switch Q9 is electrically connected to the voltage input terminal IN, thus the first terminal of the voltage conversion circuit 130 is electrically connected to the voltage input terminal IN, and the voltage input terminal IN is electrically connected to the input voltage Vin, that is, the first terminal of the voltage conversion circuit 130 is electrically connected to the input voltage Vin. The second terminal of the voltage conversion circuit 130 is the second terminal of the inductor L. The second terminal of the inductor L is grounded, thus the second terminal of the voltage conversion circuit 130 is grounded. The third terminal of the voltage conversion circuit 130 is the second terminal of the tenth switching transistor Q10. The second terminal of the tenth switching transistor Q10 is electrically connected to the voltage output terminal Vout. Therefore, the third terminal of the voltage conversion circuit 130 is electrically connected to the voltage output terminal OUT.

[0032] The main control circuit 110 can receive a state drive signal PWM, and can control the on / off state of the ninth switch Q9 based on the state drive signal PWM. For example, if the state drive signal PWM is the first state drive signal, i.e., the discharge state drive signal, the main control circuit 110 can control the ninth switch Q9 to be turned off; if the state drive signal PWM is the second state drive signal, i.e., the charging state drive signal, the main control circuit 110 can control the ninth switch Q9 to be turned on.

[0033] The main control circuit 110 can also control the on / off state between its first and third terminals based on the state drive signal PWM. Since the third terminal of the main control circuit 110 is electrically connected to the input voltage Vin, and the first terminal of the main control circuit 110 is electrically connected to the first plate of the first bootstrap capacitor C1, the main control circuit 110 can control the on / off state between the first plate of the first bootstrap capacitor C1 and the input voltage Vin based on the state drive signal PWM. For example, if the state drive signal PWM is a discharge state drive signal, the main control circuit 110 can conduct the input voltage Vin and the first plate of the first bootstrap capacitor C1. The second plate of the first bootstrap capacitor C1 is electrically connected to the control terminal of the tenth switch Q10, and the first bootstrap capacitor C1 can discharge to the control terminal of the tenth switch Q10. Thus, under the action of the discharge state drive signal, the main control circuit 110 can control the first bootstrap capacitor C1 to provide a sub-control voltage V' to the control terminal of the tenth switch Q10. The control voltage V' must be greater than or equal to the threshold voltage Vth of the tenth switch Q10. At this time, the tenth switch Q10 will quickly turn on.

[0034] Figure 3A An equivalent circuit diagram is provided for an embodiment of this application, such as... Figure 3A As shown, the gate capacitance of the tenth switch Q10 is Cg. Under the action of the discharge state drive signal, the first bootstrap capacitor C1 can charge the gate capacitor Cg, so that the voltage on one plate of the gate capacitor Cg is the sub-control voltage V', and the voltage on the other plate of the gate capacitor Cg is the output voltage Vout.

[0035] See also Figure 2 The auxiliary control circuit 120 can receive a state drive signal PWM. Based on the state drive signal PWM, it can control the on / off state between the first and second terminals of the auxiliary control circuit 120. Since the first terminal of the auxiliary control circuit 120 is electrically connected to the control terminal of the tenth switch Q10, and the second terminal of the auxiliary control circuit 120 is electrically connected to the input voltage Vin, the auxiliary control circuit 120 can control the on / off state between the input voltage Vin and the control terminal of the tenth switch Q10. For example, if the state drive signal PWM is a discharge state drive signal, the auxiliary control circuit 120 can turn on the input voltage Vin and the control terminal of the tenth switch Q10. Thus, under the action of the discharge state drive signal, the auxiliary control circuit 120 can provide the input voltage Vin to the control terminal of the tenth switch Q10, causing the control voltage of the control terminal of the tenth switch Q10 to rise from V' to Vin+V', ensuring that the tenth switch Q10 is fully turned on.

[0036] Figure 3B Another equivalent circuit diagram provided for an embodiment of this application, such as Figure 3B As shown, under the action of the discharge state drive signal, the first bootstrap capacitor C1 charges the gate capacitor Cg, and the input voltage Vin charges the gate capacitor Cg through the auxiliary control circuit 120, so that the voltage on the plate of the gate capacitor Cg is pulled up from V' to Vout+V'.

[0037] In summary, under the action of the discharge state drive signal, the main control circuit 110 can control the first bootstrap capacitor C1 to provide a sub-control voltage V' to the control terminal of the tenth switch Q10, enabling the tenth switch Q10 to conduct quickly. Simultaneously, the auxiliary control circuit 120 can provide an input voltage Vin to the control terminal of the tenth switch Q10, raising the control voltage at the control terminal of the tenth switch Q10 to Vin+V', ensuring that the tenth switch Q10 is fully turned on. Thus, the control voltage at the first control terminal of the voltage conversion circuit 130 is partly provided by the first bootstrap capacitor C1 and partly by the input voltage Vin. This reduces the voltage provided by the first bootstrap capacitor C1, allowing for the use of a smaller bootstrap capacitor, reducing the area occupied by the bootstrap capacitor, and consequently reducing the area occupied by the negative voltage converter, which is beneficial for the miniaturization of the device.

[0038] The control voltage V = Vin + V' at the control terminal of the tenth switch Q10 enables the conduction of the first and second terminals of the tenth switch Q10, i.e., the output voltage Vout and the first terminal of inductor L. Under the action of the discharge state drive signal, the ninth switch Q9 is turned off and the tenth switch Q10 is turned on, and inductor L is in a discharging state. Since the voltage at the first terminal of inductor L is Vin and the voltage at the second terminal of inductor L is 0 at the end of the charging state, and the current direction of inductor L is from the first terminal to the second terminal, the current direction of inductor L in the discharging state is still from the first terminal to the second terminal, i.e., the current of inductor L flows from the voltage output terminal OUT through inductor L to ground. In this way, the first plate of the output capacitor Cout is discharged, and a negative voltage, i.e., the output voltage Vout, can be output at the voltage output terminal OUT. Therefore, the voltage conversion circuit 130 can convert the input voltage Vin into a negative output voltage Vout.

[0039] In this embodiment, the negative voltage converter includes a main control circuit, an auxiliary control circuit, a first bootstrap capacitor, and a voltage conversion circuit. The control terminal of the main control circuit and the first control terminal of the auxiliary control circuit are both electrically connected to a state drive signal. The first terminal of the main control circuit is electrically connected to the first plate of the first bootstrap capacitor. The second plate of the first bootstrap capacitor and the first terminal of the auxiliary control circuit are both electrically connected to the first control terminal of the voltage conversion circuit. The second terminal of the auxiliary control circuit is electrically connected to the input voltage. The second terminal of the main control circuit is electrically connected to the second control terminal of the voltage conversion circuit. The third terminal of the main control circuit is electrically connected to the input voltage. The first terminal of the voltage conversion circuit is electrically connected to the voltage input terminal, which is externally connected to the input voltage. The second terminal of the voltage conversion circuit is grounded. The third terminal of the voltage conversion circuit is electrically connected to the voltage output terminal. The main control circuit can... Under the action of the first state drive signal, the first bootstrap capacitor provides a sub-control voltage to the first control terminal of the voltage conversion circuit; the auxiliary control circuit can provide an input voltage to the first control terminal of the voltage conversion circuit under the action of the first state drive signal; the voltage conversion circuit can convert the input voltage into an output voltage under the action of the control voltage, wherein the control voltage is the sum of the input voltage and the sub-control voltage, and the output voltage is a negative voltage. Thus, under the action of the first state drive signal, the first bootstrap capacitor and the input voltage jointly provide a control voltage to the first control terminal of the voltage conversion circuit, which can reduce the voltage provided by the first bootstrap capacitor. In this way, a bootstrap capacitor with a smaller capacitance value can be used, which can reduce the area occupied by the bootstrap capacitor, thereby reducing the area occupied by the negative voltage converter, which is conducive to the miniaturization of the device.

[0040] In some embodiments, Figure 4 This is a schematic diagram of another negative voltage converter provided in an embodiment of this application. Figure 4 for Figure 1 Based on the embodiment shown, the auxiliary control circuit 120 includes a first switch Q1 and a second switch Q2.

[0041] Specifically, the control terminal of the first switch Q1 is electrically connected to the state drive signal PWM, the first terminal of the first switch Q1 is electrically connected to the input voltage Vin, the second terminal of the first switch Q1 is electrically connected to the first terminal of the second switch Q2, the second terminal of the second switch Q2 is electrically connected to the first control terminal of the voltage conversion circuit 130, and the control terminal of the second switch Q2 is electrically connected to the clamping voltage V. CLP .

[0042] For example, if the state drive signal PWM is a discharge state drive signal, then the first terminal and the second terminal of the first switch Q1 are turned on, that is, the input voltage Vin is turned on by the first terminal of the second switch Q2. At the clamping voltage V... CLPUnder the action of the second switch Q2, the first terminal of the second switch Q2 and the second terminal of the second switch Q2 are turned on. In this way, the input voltage Vin is turned on with the first control terminal of the voltage conversion circuit 130, and part of the control voltage can be provided to the first control terminal of the voltage conversion circuit 130.

[0043] Clamping voltage V CLP This can be generated by clamping circuit 140, such as Figure 5 As shown, Figure 5 This is a schematic diagram of a clamping circuit provided in an embodiment of this application. Figure 5 for Figure 4 Based on the embodiment shown, the negative voltage converter 100 further includes a clamping circuit 140. The clamping circuit 140 includes a current source Ib, a clamping switch Dz, and a capacitor C. The current source Ib is electrically connected to the input voltage Vin. The output terminal of the current source Ib is electrically connected to the negative terminal of the clamping switch Dz, the first plate of the capacitor C, and the control terminal of the second switch Q2. The positive terminal of the clamping switch Dz and the second plate of the capacitor C are both electrically connected to the voltage output terminal OUT.

[0044] like Figure 5 As shown, the current source Ib and the input voltage Vin can convert the input voltage Vin into a constant current and output it. The current flows into the first plate of capacitor C, so the voltage across the first plate of capacitor C is a positive voltage, i.e., V. CLP The voltage across the second plate of capacitor C is negative, Vout. Therefore, the positive voltage of clamping switch Dz is Vout, and the negative voltage of clamping switch Dz is Vout. CLP The clamping switch Dz can be, for example, a Zener diode. A reverse voltage is applied across the Zener diode, and its reverse breakdown voltage is 5.5V. Therefore, V... CLP =5.5+Vout.

[0045] If the input voltage Vin = 4V, then the output voltage Vout ≈ -4V. Thus, V CLP =5.5+Vout≈1.5V, which is greater than the threshold voltage of the control terminal of the second switch Q2, and can turn on the first terminal and the second terminal of the second switch Q2.

[0046] In some embodiments, Figure 6 This is a schematic diagram of another negative voltage converter provided in an embodiment of this application. Figure 6 for Figure 4Based on the embodiment shown, the negative voltage converter 100 further includes a second bootstrap capacitor C2. The first plate of the second bootstrap capacitor C2 is electrically connected to the first plate of the first bootstrap capacitor C1. The second plate of the second bootstrap capacitor C2 is electrically connected to the second control terminal of the auxiliary control circuit 120. The third terminal of the auxiliary control circuit 120 is electrically connected to the voltage output terminal OUT. The fourth terminal of the main control circuit 110 is grounded.

[0047] The auxiliary control circuit 120 is also used to provide an output voltage Vout to the first control terminal of the voltage conversion circuit 130 under the action of the second state drive signal. The voltage conversion circuit 130 is also used to store the electrical energy provided by the input voltage Vin under the action of the output voltage Vout.

[0048] For example, the state drive signal PWM is the second state drive signal, i.e., the charging state drive signal. Based on the charging state drive signal, the main control circuit 110 can control the ninth switch Q9 to turn on, and can also turn on the fourth terminal of the main control circuit 110 and the first terminal of the main control circuit 110. Since the fourth terminal of the main control circuit 110 is grounded, and the first terminal of the main control circuit 110 is electrically connected to the first plate of the second bootstrap capacitor C2, the first plate of the second bootstrap capacitor C2 can be connected to ground. The voltage of the first plate of the second bootstrap capacitor C2 decreases. Since the voltage on the second bootstrap capacitor C2 cannot change abruptly, the voltage of the second plate of the second bootstrap capacitor C2 decreases. Thus, the voltage of the second control terminal of the auxiliary control circuit 120 decreases. At this time, the third terminal of the auxiliary control circuit 120 is connected to the first terminal of the auxiliary control circuit 120.

[0049] Simultaneously, the auxiliary control circuit 120 can disconnect its first and second terminals based on the charging state drive signal. Therefore, the voltage at the control terminal of the tenth switch Q10 is the voltage at the third terminal of the auxiliary control circuit 120, i.e., the output voltage Vout. At this time, the tenth switch Q10 is in the off state.

[0050] In summary, under the action of the charging state drive signal, the ninth switch Q9 is turned on and the tenth switch Q10 is turned off, which means that the input voltage Vin and the first terminal of the inductor L can be connected. The direction of the current is that the input voltage Vin flows to ground through the inductor L, and the direction of the current in the inductor L is that the current flows from the first terminal of the inductor L to the second terminal of the inductor L. The inductor L can store energy, that is, the inductor L is in a charging state.

[0051] In some embodiments, see continue to see Figure 6 The auxiliary control circuit 120 also includes an inverter 121, a third switch Q3, a fourth switch Q4, a fifth switch Q5, and a sixth switch Q6.

[0052] Specifically, the input terminal of inverter 121 is electrically connected to the state drive signal PWM, the output terminal of inverter 121 is electrically connected to the control terminal of the third switch Q3, the first terminal of the third switch Q3 is electrically connected to the input voltage Vin, the second terminal of the third switch Q3 is electrically connected to the first terminal of the fourth switch Q4, and the control terminal of the fourth switch Q4 is electrically connected to the clamping voltage V. CLP The second terminal of the fourth switch Q4 is electrically connected to the control terminal of the fifth switch Q5 and the first terminal of the sixth switch Q6. The first terminal of the fifth switch Q5 is electrically connected to the first control terminal of the voltage conversion circuit 130. The second terminals of both the fifth switch Q5 and the sixth switch Q6 are electrically connected to the voltage output terminal OUT. The control terminal of the sixth switch Q6 is electrically connected to the second plate of the second bootstrap capacitor C2.

[0053] For example, if the state drive signal PWM is a discharge state drive signal, inverter 121 can invert the discharge state drive signal and input it to the control terminal of the third switch Q3, causing the terminals of the third switch Q3 to be disconnected. Thus, the input voltage Vin is disconnected from the first terminal of the fourth switch Q4. The control terminal of the fourth switch Q4 is electrically connected to the clamping voltage V. CLP Then, the fourth switch Q4 is turned on. At this time, the input voltage Vin is disconnected from the control terminal of the fifth switch Q5, that is, the input voltage Vin is disconnected from the first control terminal of the voltage conversion circuit 130. The first switch Q1 is turned on under the action of the discharge state drive signal, and the second switch Q2 is turned on under the clamping voltage V. CLP Under its influence, it is in a conducting state, which can connect the input voltage Vin to the first control terminal of the voltage conversion circuit 130.

[0054] If the PWM state drive signal is a charging state drive signal, the first switch Q1 is in the off state. Inverter 121 can invert the charging state drive signal and input it to the control terminal of the third switch Q3, putting the third switch Q3 in the on state, that is, turning on the input voltage Vin and the first terminal of the fourth switch Q4. The control terminal of the fourth switch Q4 is electrically connected to the clamping voltage V. CLP When the fourth switch Q4 is turned on, the input voltage Vin is connected to the control terminal of the fifth switch Q5. Furthermore, under the influence of the charging state drive signal, the voltage at the second plate of the second bootstrap capacitor C2 decreases, meaning the voltage at the control terminal of the sixth switch Q6 decreases. When the sixth switch Q6 is turned off, the voltage output terminal OUT is disconnected from the control terminal of the fifth switch Q5. Thus, the voltage at the control terminal of the fifth switch Q5 is pulled high to the input voltage Vin, and the two ends of the fifth switch Q5 are turned on, connecting the voltage output terminal OUT to the first control terminal of the voltage conversion circuit 130, pulling the voltage at the first control terminal of the voltage conversion circuit 130 down to Vout.

[0055] In some embodiments, Figure 7 This is a schematic diagram of another negative voltage converter provided in an embodiment of this application. Figure 7 for Figure 6 Based on the embodiment shown, the auxiliary control circuit 120 further includes a seventh switch Q7.

[0056] Among them, the first terminal of the seventh switch Q7 is electrically connected to the second plate of the second bootstrap capacitor C2, the second terminal of the seventh switch Q7 is electrically connected to the voltage output terminal OUT, and the control terminal of the seventh switch Q7 is electrically connected to the control terminal of the fifth switch Q5.

[0057] For example, such as Figure 7 As shown, the control terminal of the seventh switch Q7 is electrically connected to the control terminal of the fifth switch Q5. When the voltage at the control terminal of the fifth switch Q5 is pulled up to the input voltage Vin, the voltage at the control terminal of the seventh switch Q7 is the input voltage Vin, which can turn on the first terminal and the second terminal of the seventh switch Q7, that is, pull down the voltage of the second plate of the second bootstrap capacitor C2 to the output voltage Vout.

[0058] Thus, even if the second plate of the second bootstrap capacitor C2 occasionally outputs a spike pulse, the seventh switch Q7 can pull the voltage of the second plate of the second bootstrap capacitor C2 down to the output voltage Vout, avoiding the false triggering of the sixth switch Q6, thereby avoiding the false triggering of the fifth switch Q5, so that the fifth switch Q5 can remain in the conducting state, ensuring the stability of the voltage conversion circuit 130.

[0059] In this embodiment, the auxiliary control circuit further includes a seventh switch, the first end of which is electrically connected to the second plate of the second bootstrap capacitor, the second end of which is electrically connected to the voltage output terminal, and the control terminal of which is electrically connected to the control terminal of the fifth switch. Thus, the seventh switch can prevent the fifth switch from being falsely triggered, so that the fifth switch Q5 is always in the conducting state, thereby ensuring the stability of the voltage conversion circuit.

[0060] In some embodiments, see continue to see Figure 7 The negative voltage converter 100 also includes an eighth switch Q8, wherein the second plate of the first bootstrap capacitor C1 is electrically connected to the first terminal of the eighth switch Q8, and the second terminal of the eighth switch Q8 is electrically connected to the first control terminal of the voltage conversion circuit 130.

[0061] The eighth switch Q8 is used to disconnect the first control terminal of the voltage conversion circuit 130 from the second plate of the first bootstrap capacitor C1.

[0062] For example, such as Figure 7As shown, under the action of the charging state drive signal, the sixth switch Q6 can pull down the voltage at the control terminal of the tenth switch Q10 to Vout, and the eighth switch Q8 can disconnect the connection between the control terminal of the tenth switch Q10 and the second plate of the first bootstrap capacitor C1, preventing the voltage at the second plate of the first bootstrap capacitor C1 from being pulled down to Vout. At this time, the voltage difference between the two plates of the first bootstrap capacitor C1 is no longer Vout, but is approximately equal to the threshold voltage Vth of the tenth switch Q10, and Vth > Vout.

[0063] Thus, the first bootstrap capacitor C1 can be a standard 5V device, eliminating the need for a high-voltage capacitor and reducing the cost of the negative voltage converter.

[0064] For example, Figure 8 This is a schematic diagram of another negative voltage converter provided in an embodiment of this application. Figure 8 for Figure 1 Based on the embodiment shown, the main control circuit 110 includes: an eleventh switch Q11, a twelfth switch Q12, a thirteenth switch Q13, and a fourteenth switch Q14.

[0065] Among them, the control terminals of the eleventh switch Q11, the twelfth switch Q12, the thirteenth switch Q13, and the fourteenth switch Q14 are all electrically connected to the state drive signal PWM. The first terminal of the eleventh switch Q11 is electrically connected to the input voltage Vin, and the second terminal of the eleventh switch Q11 is electrically connected to the first terminal of the twelfth switch Q12 and the second control terminal of the voltage conversion circuit 130. The second terminal of the twelfth switch Q12 is grounded. The first terminal of the thirteenth switch Q13 is electrically connected to the input voltage Vin, and the second terminal of the thirteenth switch Q13 is electrically connected to the first terminal of the fourteenth switch Q14 and the first plate of the first bootstrap capacitor C1. The second terminal of the fourteenth switch Q14 is grounded.

[0066] For example, the state drive signal PWM is the discharge state drive signal, with the eleventh switch Q11 and the thirteenth switch Q13 both turned on, and the twelfth switch Q12 and the fourteenth switch Q14 both turned off. Figure 9A As shown. Thus, the input voltage Vin is connected to the control terminal of the ninth switch Q9, meaning the ninth switch Q9 is turned off, and the input voltage Vin is connected to the first plate of the first bootstrap capacitor C1. When the input voltage Vin and the first plate of the first bootstrap capacitor C1 are connected, the first bootstrap capacitor C1 provides a sub-control voltage V' to the control terminal of the tenth switch Q10. Furthermore, the main control circuit 110 provides the input voltage Vin to the control terminal of the tenth switch Q10 to control the tenth switch Q10 to turn on.

[0067] The PWM state drive signal is the charging state drive signal. The eleventh and thirteenth switches Q11 and Q13 are both off, while the twelfth and fourteenth switches Q12 and Q14 are both on. Figure 9B As shown. Thus, the control terminal of the ninth switch Q9 is connected to ground, that is, the ninth switch Q9 is turned on, and the first plate of the first bootstrap capacitor C1 is connected to ground. When the first plate of the first bootstrap capacitor C1 is connected to ground, the auxiliary control circuit 120 can provide an output voltage Vout to the control terminal of the tenth switch Q10 to control the tenth switch Q10 to be turned off.

[0068] It should be noted that, in this embodiment, the charging state drive signal is a high-level signal, the discharging state drive signal is a low-level signal, and the first switch Q1, the third switch Q3, the ninth switch Q9, the eleventh switch Q11, and the thirteenth switch Q13 are PMOS transistors, while the second switch Q2, the fourth switch Q4, the fifth switch Q5, the sixth switch Q6, the tenth switch Q10, the twelfth switch Q12, and the fourteenth switch Q14 are NMOS transistors. In practical applications, the charging state drive signal can also be a low-level signal, the discharging state drive signal a high-level signal, the first switch Q1, the third switch Q3, the ninth switch Q9, the eleventh switch Q11, and the thirteenth switch Q13 are NMOS transistors, and the second switch Q2, the fourth switch Q4, the fifth switch Q5, the sixth switch Q6, the tenth switch Q10, the twelfth switch Q12, and the fourteenth switch Q14 are PMOS transistors.

[0069] This application also provides a semiconductor chip, which includes the negative voltage converter 100 provided in any of the above embodiments.

[0070] For example, integrating the negative voltage converter 100 provided in any of the above embodiments into a semiconductor chip can reduce the size of the negative voltage converter 100, which is beneficial to the miniaturization of the negative voltage converter 100.

[0071] The semiconductor chip provided in this application includes the negative voltage converter 100 provided in any of the above embodiments, and has the same functional modules and beneficial effects as the negative voltage converter 100, which will not be described again here.

[0072] The above-disclosed embodiments are merely specific examples of this application. However, the embodiments of this application are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of this application.

[0073] The term "comprising" as used in this application does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. This application can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims listing several means, several units of these means may be embodied by the same item of hardware. The use of "first," "second," and "third," etc., does not indicate any order and should be interpreted as names. Unless otherwise specified, the steps in the above embodiments should not be construed as limiting the order of execution.

[0074] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A negative voltage converter, characterized in that, include: Main control circuit, auxiliary control circuit, first bootstrap capacitor and voltage conversion circuit; The control terminal of the main control circuit and the first control terminal of the auxiliary control circuit are both electrically connected to the state drive signal. The first terminal of the main control circuit is electrically connected to the first plate of the first bootstrap capacitor. The second plate of the first bootstrap capacitor and the first terminal of the auxiliary control circuit are both electrically connected to the first control terminal of the voltage conversion circuit. The second terminal of the auxiliary control circuit is electrically connected to the input voltage. The second terminal of the main control circuit is electrically connected to the second control terminal of the voltage conversion circuit. The third terminal of the main control circuit is electrically connected to the input voltage. The first terminal of the voltage conversion circuit is electrically connected to the voltage input terminal. The voltage input terminal is externally connected to the input voltage. The second terminal of the voltage conversion circuit is grounded. The third terminal of the voltage conversion circuit is electrically connected to the voltage output terminal. The main control circuit is used to control the first bootstrap capacitor to provide a sub-control voltage to the first control terminal of the voltage conversion circuit under the action of the first state drive signal. The auxiliary control circuit is used to provide the input voltage to the first control terminal of the voltage conversion circuit under the action of the first state drive signal; The voltage conversion circuit is used to convert the input voltage into an output voltage under the action of a control voltage; wherein the control voltage is the sum of the input voltage and the sub-control voltage, and the output voltage is a negative voltage.

2. The negative voltage converter according to claim 1, characterized in that, The auxiliary control circuit includes a first switching transistor and a second switching transistor; The control terminal of the first switch is electrically connected to the state drive signal, the first terminal of the first switch is electrically connected to the input voltage, the second terminal of the first switch is electrically connected to the first terminal of the second switch, the second terminal of the second switch is electrically connected to the first control terminal of the voltage conversion circuit, and the control terminal of the second switch is electrically connected to the clamping voltage.

3. The negative voltage converter according to claim 2, characterized in that, It also includes a second bootstrap capacitor; The first plate of the second bootstrap capacitor is electrically connected to the first plate of the first bootstrap capacitor, the second plate of the second bootstrap capacitor is electrically connected to the second control terminal of the auxiliary control circuit, the third terminal of the auxiliary control circuit is electrically connected to the voltage output terminal, and the fourth terminal of the main control circuit is grounded. The auxiliary control circuit is also used to provide the output voltage to the first control terminal of the voltage conversion circuit under the action of the second state drive signal; The voltage conversion circuit is also used to store the electrical energy provided by the input voltage under the action of the output voltage.

4. The negative voltage converter according to claim 3, characterized in that, The auxiliary control circuit also includes an inverter, a third switch, a fourth switch, a fifth switch, and a sixth switch; The input terminal of the inverter is electrically connected to the state drive signal, the output terminal of the inverter is electrically connected to the control terminal of the third switch, the first terminal of the third switch is electrically connected to the input voltage, the second terminal of the third switch is electrically connected to the first terminal of the fourth switch, the control terminal of the fourth switch is electrically connected to the clamping voltage, and the second terminal of the fourth switch is electrically connected to the control terminal of the fifth switch and the first terminal of the sixth switch. The first terminal of the fifth switch is electrically connected to the first control terminal of the voltage conversion circuit, the second terminals of the fifth switch and the sixth switch are both electrically connected to the voltage output terminal, and the control terminal of the sixth switch is electrically connected to the second plate of the second bootstrap capacitor.

5. The negative voltage converter according to claim 4, characterized in that, The auxiliary control circuit also includes: a seventh switching transistor; The first terminal of the seventh switch is electrically connected to the second plate of the second bootstrap capacitor, the second terminal of the seventh switch is electrically connected to the voltage output terminal, and the control terminal of the seventh switch is electrically connected to the control terminal of the fifth switch.

6. The negative voltage converter according to claim 3, characterized in that, Also includes: Eighth switching transistor; The second plate of the first bootstrap capacitor is electrically connected to the first terminal of the eighth switching transistor, and the second terminal of the eighth switching transistor is electrically connected to the first control terminal of the voltage conversion circuit. The eighth switch is used to control the disconnection between the first control terminal of the voltage conversion circuit and the second plate of the first bootstrap capacitor.

7. The negative voltage converter according to any one of claims 2-6, characterized in that, Also includes: Clamping circuit; The clamping circuit includes a current source, a clamping switch transistor, and a capacitor. The current source is electrically connected to the input voltage. The output terminal of the current source is electrically connected to the negative terminal of the clamping switch transistor, the first plate of the capacitor, and the control terminal of the second switch transistor. The positive terminal of the clamping switch transistor and the second plate of the capacitor are both electrically connected to the voltage output terminal.

8. The negative voltage converter according to any one of claims 1-6, characterized in that, The voltage conversion circuit includes: an inductor, an output capacitor, a ninth switch, and a tenth switch; The first terminal of the ninth switch is electrically connected to the input voltage, the control terminal of the ninth switch is electrically connected to the second terminal of the main control circuit, the second terminal of the ninth switch is electrically connected to the first terminal of the inductor and the first terminal of the tenth switch, the control terminal of the tenth switch is electrically connected to the second plate of the first bootstrap capacitor, the second terminal of the tenth switch and the first plate of the output capacitor are both electrically connected to the voltage output terminal, and the second plate of the output capacitor and the second terminal of the inductor are grounded.

9. The negative voltage converter according to any one of claims 1-6, characterized in that, The main control circuit includes: an eleventh switch, a twelfth switch, a thirteenth switch, and a fourteenth switch; The control terminals of the eleventh switch, the twelfth switch, the thirteenth switch, and the fourteenth switch are all electrically connected to the state drive signal. The first terminal of the eleventh switch is electrically connected to the input voltage. The second terminal of the eleventh switch is electrically connected to the first terminal of the twelfth switch and the second control terminal of the voltage conversion circuit. The second terminal of the twelfth switch is grounded. The first terminal of the thirteenth switch is electrically connected to the input voltage, the second terminal of the thirteenth switch is electrically connected to the first terminal of the fourteenth switch and the first plate of the first bootstrap capacitor, and the second terminal of the fourteenth switch is grounded.

10. The negative voltage converter according to claim 4, characterized in that, Under the action of the first state drive signal, both the first and second switching transistors are turned on, while the third switching transistor is turned off. Under the action of the second state drive signal, the third, fourth and fifth switches are all turned on, while the first and sixth switches are all turned off.

11. A semiconductor chip, characterized in that, Includes the negative voltage converter according to any one of claims 1-10.

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