Start control circuit and chip

Abstract

The utility model discloses a starting control circuit and a chip. The starting control circuit comprises a first switch tube, a first voltage unit and a control unit. The control end of the first switch tube is used for receiving input voltage, the second end of the first switch tube is connected with power voltage, the first voltage unit is connected with the first end of the first switch tube, and the first voltage unit is used for increasing the voltage of the first end of the first switch tube and generating first voltage based on starting of the first switch tube. The control unit is connected with the first voltage unit to generate a control voltage based on the first voltage. According to the starting control circuit and the chip, the design of starting threshold voltage and reference voltage is combined, and the functions of closing the circuit within a threshold value, starting the circuit outside the threshold value and adjusting circuit output based on the input voltage are achieved only through one input voltage. The design can be applied to various chips, the use of pins can be reduced, and the chip area and cost can be reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of integrated circuits, and in particular relates to a startup control circuit and a chip. Background Art

[0002] In the prior art, a startup unit and a control circuit are usually provided in the chip, wherein the startup unit starts the control circuit after receiving a startup signal exceeding a threshold value, and turns on the chip, and turns off the chip when the signal is below the threshold value. The control circuit receives a reference voltage, which determines the final output voltage of the chip. A startup signal pin and a reference voltage pin are also provided on the chip.

[0003] In the above solution, at least two pins are required on the chip. However, due to area or cost considerations, or in some specific packages with fewer pins, it is necessary to reduce the use of pins, while retaining the functions of starting threshold and adjusting output voltage.

[0004] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to a person skilled in the art. Utility Model Content

[0005] The utility model aims to provide a startup control circuit and a chip, which can realize the functions of over-threshold startup and adjusting circuit output by only one input voltage.

[0006] In order to achieve the above-mentioned purpose, a specific embodiment of the utility model provides a startup control circuit, including a first switch tube, a first voltage unit and a control unit, the control end of the first switch tube is used to receive an input voltage, the second end of the first switch tube is connected to the power supply voltage, the first voltage unit is connected to the first end of the first switch tube, the first voltage unit is used to raise the voltage of the first end of the first switch tube and generate a first voltage based on the opening of the first switch tube, and the control unit is connected to the first voltage unit to generate a control voltage based on the first voltage.

[0007] In one or more embodiments of the present invention, the first voltage unit includes a first current source, a second current source and a first resistor, the first end of the first current source is connected to the power supply voltage, the second end of the first current source and the first end of the first resistor are connected to the first end of the first switch tube, the second end of the first resistor is connected to the first end of the second current source to generate a first voltage, and the second end of the second current source is connected to the ground voltage.

[0008] In one or more embodiments of the present invention, the control unit includes an amplifier, an input end of the amplifier is connected to the first voltage unit to receive the first voltage, and an output end of the amplifier is used to generate a control voltage.

[0009] In one or more embodiments of the present invention, the control unit includes an amplifier, a first input terminal of the amplifier is connected to a first voltage unit to receive a first voltage, a second input terminal of the amplifier is used to receive a bias voltage, and the amplifier is used to generate a control voltage based on the first voltage and the bias voltage.

[0010] In one or more embodiments of the present invention, the control circuit also includes a second switch tube and a second voltage unit, the control end of the second switch tube is used to receive the feedback voltage of the subsequent circuit, the second end of the second switch tube is connected to the power supply voltage, the second voltage unit is connected to the first end of the second switch tube, the second voltage unit is used to raise the voltage of the first end of the second switch tube and generate a second voltage based on the turning on of the second switch tube, and the control unit is connected to the second voltage unit to generate a control voltage based on the second voltage and the first voltage.

[0011] In one or more embodiments of the present invention, the second voltage unit includes a third current source, a fourth current source and a second resistor, the first end of the third current source is connected to the power supply voltage, the second end of the third current source and the first end of the second resistor are connected to the first end of the second switch tube, the second end of the second resistor is connected to the first end of the fourth current source to generate a second voltage, and the second end of the fourth current source is connected to the ground voltage.

[0012] In one or more embodiments of the present invention, the control unit includes an amplifier, a first input terminal of the amplifier is connected to a first voltage unit to receive a first voltage, a second input terminal of the amplifier is used to receive a second voltage, and the amplifier is used to generate a control voltage based on the first voltage and the second voltage.

[0013] In one or more embodiments of the utility model, the amplifier includes a fifth current source, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor and an eighth transistor; the first end of the fifth current source is connected to the power supply voltage, the second end of the fifth current source is connected to the first end of the first transistor and the first end of the second transistor, the control end of the first transistor is used to form the first input end of the amplifier, the control end of the second transistor is used to form the second input end of the amplifier, the second end of the first transistor is connected to the second end of the third transistor, the control end of the third transistor, and the control end of the fourth transistor, the first end of the third transistor and the first end of the fourth transistor are connected to the ground voltage, the second end of the fourth transistor is connected to the second end of the seventh transistor, the control end of the seventh transistor and the control end of the eighth transistor, the first end of the seventh transistor and the first end of the eighth transistor are connected to the power supply voltage; the second end of the second transistor is connected to the second end of the fifth transistor, the control end of the fifth transistor, and the control end of the sixth transistor, the first end of the fifth transistor and the first end of the sixth transistor are connected to the ground voltage, and the second end of the sixth transistor is connected to the second end of the eighth transistor and forms the output end of the amplifier.

[0014] A specific embodiment of the utility model further provides a chip, on which the above-mentioned startup control circuit is arranged. The chip is also provided with a first pin connected to the control end of the first switch tube, and the first pin is used to receive an input voltage.

[0015] In one or more embodiments of the present invention, a second pin connected to the control end of the second switch tube is further provided on the chip, and the second pin is used to receive a feedback voltage of a subsequent circuit.

[0016] Compared with the prior art, the startup control circuit and chip of the utility model combine the design of startup threshold voltage and reference voltage, and realize the function of closing the circuit within the threshold, starting the circuit outside the threshold, and adjusting the circuit output based on the input voltage through only one input voltage. This design can be applied to various chips, can reduce the use of pins, and is conducive to reducing chip area and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the utility model, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1The figure is a circuit schematic diagram of a startup control circuit in one embodiment of the utility model. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0020] The words "coupled" or "connected" or "connected" in the specification include both direct connection and indirect connection. Indirect connection is a connection through an intermediate medium, such as a connection through an electrically conductive medium, which may have parasitic inductance or parasitic capacitance; indirect connection may also include connection through other active or passive devices on the basis of achieving the same or similar functional purposes, such as connection through circuits or components such as switches and follower circuits. In addition, in the present utility model, words such as "first" and "second" are mainly used to distinguish one technical feature from another technical feature, and do not necessarily require or imply that there is a certain actual relationship, quantity or order between these technical features.

[0021] like Figure 1 As shown, the startup control circuit in one embodiment of the present utility model includes a control unit, a first switch tube S1, a first voltage unit, a second switch tube S2 and a second voltage unit.

[0022] Among them, the control end of the first switch tube S1 is used to receive the input voltage VIN, the second end of the first switch tube S1 is connected to the power supply voltage VDD, the first voltage unit is connected to the first end of the first switch tube S1, and the first voltage unit is used to raise the voltage of the first end of the first switch tube S1 and generate the first voltage V1 based on the opening of the first switch tube S1.

[0023] The control end of the second switch tube S2 is used to receive the feedback voltage VFB of the subsequent circuit, the second end of the second switch tube S2 is connected to the power supply voltage VDD, the second voltage unit is connected to the first end of the second switch tube S2, and the second voltage unit is used to raise the voltage of the first end of the second switch tube S2 and generate a second voltage V2 based on the opening of the second switch tube S2.

[0024] The control unit is connected to the first voltage unit and the second voltage unit to generate a control voltage VCON based on the first voltage V1 and the second voltage V2.

[0025] In one embodiment, the subsequent circuit is a driving circuit, which generates a driving signal based on the control of a control voltage VCON, and the feedback voltage VFB is obtained based on the voltage division of the driving signal.

[0026] In other embodiments, the subsequent circuit may also be a circuit with other functions.

[0027] like Figure 1 As shown, the first voltage unit includes a first current source I1, a second current source I2 and a first resistor R1. A first end of the first current source I1 is connected to a power supply voltage VDD, a second end of the first current source I1 and a first end of the first resistor R1 are connected to a first end of a first switch tube S1, a second end of the first resistor R1 is connected to a first end of the second current source I2 to generate a first voltage V1, and a second end of the second current source I2 is connected to a ground voltage.

[0028] The second voltage unit includes a third current source I3, a fourth current source I4 and a second resistor R2, a first end of the third current source I3 is connected to the power supply voltage VDD, a second end of the third current source I3 and a first end of the second resistor R2 are connected to a first end of the second switch tube S2, a second end of the second resistor R2 is connected to a first end of the fourth current source I4 to generate a second voltage V2, and a second end of the fourth current source I4 is connected to the ground voltage.

[0029] The control unit includes an amplifier, a first input terminal of the amplifier is connected to the second end of the first resistor R1 to receive a first voltage V1, a second input terminal of the amplifier is connected to the second end of the second resistor R2 to receive a second voltage V2, and an output terminal of the amplifier is used to generate a control voltage VCON.

[0030] In one embodiment, the amplifier includes a fifth current source I5, a first transistor M1, a second transistor M2, a third transistor M3, a fourth transistor M4, a fifth transistor M5, a sixth transistor M6, a seventh transistor M7 and an eighth transistor M8.

[0031] The first end of the fifth current source I5 is connected to the power supply voltage VDD, the second end of the fifth current source I5 is connected to the first end of the first transistor M1 and the first end of the second transistor M2, the control end of the first transistor M1 is used to form the first input end of the amplifier, and the control end of the second transistor M2 is used to form the second input end of the amplifier. The second end of the first transistor M1 is connected to the second end of the third transistor M3, the control end of the third transistor M3, and the control end of the fourth transistor M4, the first end of the third transistor M3 and the first end of the fourth transistor M4 are connected to the ground voltage, the second end of the fourth transistor M4 is connected to the second end of the seventh transistor M7, the control end of the seventh transistor M7, and the control end of the eighth transistor M8. The first end of the seventh transistor M7 and the first end of the eighth transistor M8 are connected to the power supply voltage VDD.

[0032] The second end of the second transistor M2 is connected to the second end of the fifth transistor M5, the control end of the fifth transistor M5, and the control end of the sixth transistor M6. The first end of the fifth transistor M5 and the first end of the sixth transistor M6 are connected to the ground voltage. The second end of the sixth transistor M6 is connected to the second end of the eighth transistor M8 and forms the output end of the amplifier.

[0033] In other embodiments, the amplifier may also adopt other forms of amplifier structures.

[0034] In one embodiment, the first switch tube S1, the second switch tube S2, the third transistor M3, the fourth transistor M4, the fifth transistor M5 and the sixth transistor M6 are all N-channel transistors, and the first transistor M1, the second transistor M2, the seventh transistor M7 and the eighth transistor M8 are all P-channel transistors.

[0035] In the first switch tube S1, the second switch tube S2, the first transistor M1, the second transistor M2, the third transistor M3, the fourth transistor M4, the fifth transistor M5, the sixth transistor, the seventh transistor M7 and the eighth transistor M8, the first end of each tube is a source, the second end of each tube is a drain, and the control end of each tube is a gate.

[0036] In other embodiments, the first switch tube S1, the second switch tube S2, the third transistor M3, the fourth transistor M4, the fifth transistor M5 and the sixth transistor M6 may also be P-channel transistors or other types of devices, and the first transistor M1, the second transistor M2, the seventh transistor M7 and the eighth transistor M8 may also be N-channel transistors or other types of devices, and their connection methods are adaptively adjusted.

[0037] When the input voltage VIN is less than I1*R1+VGS(S1), where I1 is the current value of the first current source I1, R1 is the resistance value of the first resistor R1, and VGS(S1) is the turn-on threshold voltage of the first switch tube S1, the first switch tube S1 is turned off, and the first voltage V1 is pulled down to the ground voltage by the second current source I2.

[0038] When the input voltage VIN exceeds I1*R1+VGS(S1), the first voltage V1 is:

[0039] V1=VIN-VGS(S1)-(I1+IS1)*R1

[0040] IS1 is the current value flowing through the first switch tube S1. It can be seen that at this time, the first voltage V1 increases with the increase of the input voltage VIN.

[0041] Similarly, when the feedback voltage VFB is less than I3*R2+VGS(S2), the second voltage V2 is 0, and when the feedback voltage VFB is greater than I3*R2+VGS(S2), the second voltage V2 is V2=VFB-VGS(S2)-(I3+IS2)*R2. Where I3 is the current value of the third current source I3, R2 is the resistance value of the second resistor R2, VGS(S2) is the conduction threshold voltage of the second switch tube S2, and IS2 is the current value flowing through the second switch tube S2.

[0042] During the rising process of the input voltage VIN, the first voltage V1 is 0 in the early stage, the amplifier does not work, the control voltage VCON is also 0, and the back-end driving circuit does not start. When the input voltage VIN exceeds the corresponding threshold, the first voltage V1 rises accordingly, and the amplifier generates the control voltage VCON, which controls the driving circuit to generate the output voltage.

[0043] The feedback voltage VFB gradually rises with the output voltage until it exceeds the corresponding threshold, and the second voltage V2 starts to rise from 0. The amplifier receives the second voltage V2 and forms a feedback loop to adjust the magnitude of the control voltage VCON, and finally controls the first voltage V1 and the second voltage V2 to reach the same voltage value, and the output voltage also reaches the voltage value corresponding to the input voltage VIN.

[0044] By adjusting and setting the parameters of the first current source I1, the first resistor R1, the third current source I3, and the second resistor R2, the input voltage VIN and the feedback voltage VFB can be adjusted respectively to make the threshold values ​​of the first voltage V1 and the second voltage V2 change. Preferably, the parameters of the third current source I3 and the first current source I1, and the second resistor R2 and the first resistor R1 are the same, so that the feedback voltage VFB and the second voltage V2, the input voltage VIN and the first voltage V1 have the same corresponding relationship, and when the amplifier is balanced, the feedback voltage VFB and the input voltage VIN are also equal, which is convenient for the design and control of the drive circuit.

[0045] In other embodiments, the second switch tube S2 and the second voltage unit may not be provided, and the second input terminal of the amplifier is used to receive a bias voltage, wherein the bias voltage may be set to a feedback voltage VFB of a subsequent drive circuit, a reference voltage or other voltage as required.

[0046] In other embodiments, the amplifier may also be a single-ended input amplifier, in which case the input end of the amplifier is connected to the first voltage unit to receive the first voltage, and the output end of the amplifier is used to generate the control voltage VCON. In this case, the amplifier directly generates the segmented control voltage VCON based on the first voltage V1 and controls the subsequent circuit to perform related work.

[0047] In other embodiments, the control unit may also be other types of control circuits.

[0048] This embodiment also provides a chip, on which the above-mentioned startup control circuit is provided, and a first pin connected to the control end of the first switch tube S1 and a second pin connected to the control end of the second switch tube S2 are also provided on the chip, the first pin is used to receive the input voltage VIN, and the second pin is used to receive the feedback voltage VFB of the subsequent circuit.

[0049] In other embodiments, when the feedback voltage VFB is not required or the subsequent circuit is also provided on the chip, the second pin may not be provided.

[0050] This solution combines the design of the startup threshold voltage and reference voltage in the prior art, and only uses one input voltage VIN to achieve the function of shutting down the circuit when the input voltage VIN is lower than the threshold, starting the circuit when it is higher than the threshold, and adjusting the circuit output based on the input voltage VIN. This design can be applied to various chips, can reduce the use of pins, and is conducive to reducing chip area and cost.

[0051] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0052] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A startup control circuit, characterized in that: It includes a first switch tube, a first voltage unit and a control unit, wherein the control end of the first switch tube is used to receive an input voltage, the second end of the first switch tube is connected to a power supply voltage, the first voltage unit is connected to the first end of the first switch tube, the first voltage unit is used to raise the voltage of the first end of the first switch tube and generate a first voltage based on the opening of the first switch tube, and the control unit is connected to the first voltage unit to generate a control voltage based on the first voltage.

2. The startup control circuit according to claim 1, characterized in that: The first voltage unit includes a first current source, a second current source and a first resistor, the first end of the first current source is connected to the power supply voltage, the second end of the first current source and the first end of the first resistor are connected to the first end of the first switch tube, the second end of the first resistor is connected to the first end of the second current source to generate a first voltage, and the second end of the second current source is connected to the ground voltage.

3. The startup control circuit according to claim 1, characterized in that: The control unit comprises an amplifier, an input terminal of the amplifier is connected to the first voltage unit to receive the first voltage, and an output terminal of the amplifier is used to generate a control voltage.

4. The startup control circuit according to claim 1, characterized in that: The control unit comprises an amplifier, a first input terminal of the amplifier is connected to the first voltage unit to receive a first voltage, a second input terminal of the amplifier is used to receive a bias voltage, and an output terminal of the amplifier is used to generate a control voltage.

5. The startup control circuit according to claim 1, characterized in that: The control circuit also includes a second switch tube and a second voltage unit, the control end of the second switch tube is used to receive the feedback voltage of the subsequent circuit, the second end of the second switch tube is connected to the power supply voltage, the second voltage unit is connected to the first end of the second switch tube, the second voltage unit is used to raise the voltage of the first end of the second switch tube and generate a second voltage based on the opening of the second switch tube, and the control unit is connected to the second voltage unit to generate a control voltage based on the second voltage and the first voltage.

6. The startup control circuit according to claim 5, characterized in that: The second voltage unit includes a third current source, a fourth current source and a second resistor, the first end of the third current source is connected to the power supply voltage, the second end of the third current source and the first end of the second resistor are connected to the first end of the second switch tube, the second end of the second resistor is connected to the first end of the fourth current source to generate a second voltage, and the second end of the fourth current source is connected to the ground voltage.

7. The startup control circuit according to claim 5, characterized in that: The control unit includes an amplifier, a first input terminal of the amplifier is connected to the first voltage unit to receive a first voltage, a second input terminal of the amplifier is used to receive a second voltage, and the amplifier is used to generate a control voltage based on the first voltage and the second voltage.

8. The startup control circuit according to claim 4 or 7, characterized in that: The amplifier includes a fifth current source, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, and an eighth transistor; The first end of the fifth current source is connected to the power supply voltage, the second end of the fifth current source is connected to the first end of the first transistor and the first end of the second transistor, the control end of the first transistor is used to form the first input end of the amplifier, the control end of the second transistor is used to form the second input end of the amplifier, the second end of the first transistor is connected to the second end of the third transistor, the control end of the third transistor, and the control end of the fourth transistor, the first end of the third transistor and the first end of the fourth transistor are connected to the ground voltage, the second end of the fourth transistor is connected to the second end of the seventh transistor, the control end of the seventh transistor and the control end of the eighth transistor, and the first end of the seventh transistor and the first end of the eighth transistor are connected to the power supply voltage; The second end of the second transistor is connected to the second end of the fifth transistor, the control end of the fifth transistor, and the control end of the sixth transistor. The first end of the fifth transistor and the first end of the sixth transistor are connected to the ground voltage. The second end of the sixth transistor is connected to the second end of the eighth transistor and forms the output end of the amplifier.

9. A chip, characterized in that: The chip is provided with a startup control circuit according to any one of claims 1 to 8, and is also provided with a first pin connected to the control end of the first switch tube, wherein the first pin is used to receive an input voltage.

10. A chip according to claim 9, characterized in that: The chip is also provided with a second pin connected to the control end of the second switch tube, and the second pin is used to receive the feedback voltage of the subsequent circuit.

Images