Power supply selection circuit

Abstract

The invention discloses a power supply selection circuit. The power supply selection circuit comprises a power tube module and a power supply selection module, and the power tube module is connected with the power supply selection module; the power tube module comprises a first power unit, a second power unit and a sixth power unit; the first power unit and the second power unit are connected between the first power supply voltage and the voltage selection output voltage, and the sixth power unit is connected between the second power supply voltage and the voltage selection output voltage; the power supply selection module is used for controlling the starting states of the first power unit, the second power unit and the sixth power unit according to the magnitude of the first power supply voltage and the second power supply voltage; the power tube module is used for selecting the input second power supply voltage and the input first power supply voltage and then outputting a voltage selection output voltage. Low-power-consumption and quick-response power supply selection is realized, and compared with a traditional power supply selection circuit, the response speed is increased, the power consumption is reduced, and the problems of backward flowing, overshoot and undershoot are avoided.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of power electronics technology, and in particular to a power selection circuit. Background Art

[0002] Power selection circuits are used in a variety of electronic devices, such as smartphones, tablets, and laptops, which usually use multiple power sources. For example, batteries and external AC adapters, power selection circuits can ensure that the device switches seamlessly between different power sources while providing necessary power management and protection functions. For example, in a smartphone, the power selection circuit can ensure that the device automatically switches to charger power when an external charger is plugged in, and automatically switches to battery power when the charger is unplugged.

[0003] At the same time, these devices also put forward requirements for the performance of the power selection circuit. For example, the power selection circuit should be able to select the most suitable power source from multiple power inputs according to the preset priority, have high conversion efficiency to reduce energy loss and heat generation, be able to quickly respond to changes in power status, ensure that it can quickly switch to the appropriate power source when needed, and have good stability. However, the power selection circuit of the traditional structure usually has high power consumption or large area, and cannot respond quickly to changes in the power source, resulting in problems such as backflow, overshoot, and undershoot. Summary of the invention

[0004] The present invention provides a power selection circuit to achieve low power consumption and fast response power selection. Compared with the traditional power selection circuit, the response speed is improved, the power consumption is reduced, and there is no problem of backflow, overshoot and undershoot.

[0005] According to one aspect of the present invention, a power selection circuit is provided, the power selection circuit comprising: a power tube module and a power selection module, the power tube module being connected to the power selection module;

[0006] The power tube module includes: a first power unit, a second power unit and a sixth power unit;

[0007] The first power unit and the second power unit are connected between a first power supply voltage and a voltage selection output voltage, and the sixth power unit is connected between a second power supply voltage and the voltage selection output voltage;

[0008] The power selection module is used to control the on-states of the first power unit, the second power unit and the sixth power unit according to the magnitudes of the first power voltage and the second power voltage; wherein the on-state of the first power unit is the same as the on-state of the second power unit, and the on-state of the first power unit is opposite to the on-state of the sixth power unit;

[0009] The power tube module is used to select the second power supply voltage and the first power supply voltage that are input and then output a voltage selection output voltage.

[0010] Optionally, the first end of the first power unit is connected to a first power supply voltage, the second end of the first power unit is connected to the first end of the second power unit, the second end of the second power unit is connected to a voltage selection output voltage, the control end of the first power unit is connected to a second voltage signal, and the control end of the second power unit is connected to a third voltage signal;

[0011] Alternatively, the first end of the second power unit is connected to the first power supply voltage, the second end of the second power unit is connected to the first end of the first power unit, the second end of the first power unit is connected to the voltage selection output voltage, the control end of the second power unit is connected to the second voltage signal, and the control end of the first power unit is connected to the third voltage signal;

[0012] The first end of the sixth power unit is connected to the second power supply voltage, the second end of the sixth power unit is connected to the voltage selection output voltage, and the control end of the sixth power unit is connected to the first voltage signal.

[0013] Optionally, the first power unit includes a first MOS tube, the second power unit includes a second MOS tube, and the sixth power unit includes a sixth MOS tube;

[0014] The first end of the first MOS transistor is connected to the first power supply voltage, the second end of the first MOS transistor is connected to the first end of the second MOS transistor, the second end of the second MOS transistor is connected to the voltage selection output voltage, the control end of the first MOS transistor is connected to the second voltage signal, and the control end of the second MOS transistor is connected to the third voltage signal;

[0015] Alternatively, the first end of the second MOS transistor is connected to the first power supply voltage, the second end of the second MOS transistor is connected to the first end of the first MOS transistor, the second end of the first MOS transistor is connected to the voltage selection output voltage, the control end of the second MOS transistor is connected to the second voltage signal, and the control end of the first MOS transistor is connected to the third voltage signal;

[0016] The first end of the sixth MOS tube is connected to the second power supply voltage, the second end of the sixth MOS tube is connected to the voltage selection output voltage, and the control end of the sixth MOS tube is connected to the first voltage signal.

[0017] Optionally, the power selection module includes: a first power selection submodule and a second power selection submodule, the first power selection submodule is connected to the second power selection submodule;

[0018] The first power selection submodule is used to output a fourth voltage signal according to the first power selection voltage and the second power selection voltage, the second power selection submodule outputs the first voltage signal, the second voltage signal and the third voltage signal in response to the fourth voltage signal, and the power tube module is used to select the input second power supply voltage and the first power supply voltage according to the first voltage signal, the second voltage signal and the third voltage signal and output the voltage selection output voltage.

[0019] Optionally, the first power selection submodule includes: a first pull-up unit, a second pull-up unit and a cross-coupling unit;

[0020] The second power selection submodule includes: a third switch unit, a fourth switch unit, a fifth switch unit, a thirteenth switch unit, a fourteenth switch unit and a fifteenth switch unit;

[0021] The first pull-up unit is connected between the first power supply voltage and the first end of the cross-coupling unit, the second pull-up unit is connected between the second power supply voltage and the second end of the cross-coupling unit, and the second end of the cross-coupling unit is also connected to the control end of the thirteenth switch unit;

[0022] The first end of the fourth switch unit is connected to the first power supply voltage, and the second end of the fourth switch unit is connected to the first end of the fourteenth switch unit and the control end of the first power unit;

[0023] The first end of the fifth switch unit is connected to the second power supply voltage, and the second end of the fifth switch unit is connected to the first end of the fifteenth switch unit and the control end of the second power unit;

[0024] The control end of the thirteenth switch unit is connected to the first power selection submodule, the second end of the thirteenth switch unit is connected to the second end of the fourteenth switch unit and then grounded, and the first end of the thirteenth switch unit is connected to the control end of the fourth switch unit, the control end of the fourteenth switch unit, the control end of the fifteenth switch unit, and the control end of the sixth power unit;

[0025] The first end of the third switch unit is connected to the first power supply voltage, the control end of the third switch unit is connected to the control end of the fifth switch unit and then grounded, and the second end of the fifteenth switch unit is grounded.

[0026] Optionally, the first pull-up unit includes a first pull-up resistor, and the second pull-up unit includes a second pull-up resistor;

[0027] The first pull-up resistor is connected between the first power supply voltage and the first end of the cross-coupling unit, and the second pull-up resistor is connected between the second power supply voltage and the second end of the cross-coupling unit.

[0028] Optionally, the cross-coupling unit comprises: a first switch subunit and a second switch subunit;

[0029] The first end of the first switch subunit is connected to the control end of the second switch subunit and the first pull-up unit, the first end of the second switch subunit is connected to the control end of the first switch subunit, the second pull-up unit and the control end of the thirteenth switch unit, and the second end of the first switch subunit is connected to the second end of the second switch subunit and then grounded.

[0030] Optionally, the first switch subunit includes a first NMOS transistor, and the second switch subunit includes a second NMOS transistor;

[0031] The first end of the first NMOS tube is connected to the control end of the second NMOS tube and the first pull-up unit, the first end of the second NMOS tube is connected to the control end of the first NMOS tube, the second pull-up unit and the control end of the thirteenth switch unit, and the second end of the first NMOS tube is connected to the second end of the second NMOS tube and then grounded.

[0032] Optionally, the relationship between the sizes of the first NMOS tube and the second NMOS tube is expressed as follows:

[0033]

[0034] Among them, W N1 is the width of the first NMOS tube, L N1 is the length of the first NMOS tube, W N2 is the width of the second NMOS tube, L N2 is the length of the second NMOS tube.

[0035] Optionally, the third switch unit includes a third MOS transistor, the fourth switch unit includes a fourth MOS transistor, and the fifth switch unit includes a fifth MOS transistor;

[0036] The thirteenth switch unit includes a thirteenth MOS tube, the fourteenth switch unit includes a fourteenth MOS tube, and the fifth switch unit includes a fifteenth MOS tube;

[0037] The second end of the cross-coupling unit is connected to the control end of the thirteenth MOS tube, the second end of the thirteenth MOS tube is connected to the second end of the fourteenth MOS tube and then grounded, the first end of the fourteenth MOS tube is connected to the second end of the fourth MOS tube and the control end of the first MOS tube, the first end of the fourth MOS tube is connected to the first power supply voltage, the first end of the thirteenth MOS tube is connected to the control end of the sixth MOS tube, the control end of the fifteenth MOS tube is connected to the second end of the third MOS tube, the control end of the third MOS tube is connected to the control end of the fifth MOS tube and then grounded, the second end of the fifteenth MOS tube is grounded, the first end of the fifteenth MOS tube is connected to the second end of the fifth MOS tube and the control end of the second MOS tube, the first end of the third MOS tube is connected to the first power supply voltage, and the first end of the fifth MOS tube is connected to the second power supply voltage.

[0038] The technical solution of the embodiment of the present invention outputs the first voltage signal, the second voltage signal and the third voltage signal through the power selection module, the power tube module selects the second power supply voltage and the first power supply voltage according to the first voltage signal, the second voltage signal and the third voltage signal and outputs the voltage selection output voltage, the power selection circuit can select the most suitable power source from multiple power inputs according to the preset priority for power supply, and can achieve low power consumption and fast response power selection. Compared with the traditional power selection circuit, the response speed is improved, the power consumption is reduced, and there will be no backflow, overshoot, and undershoot problems. In summary, the present invention solves the problem that the power selection circuit of the traditional structure usually has high power consumption or large area, and cannot respond quickly to the change of the power source, resulting in backflow, overshoot, and undershoot.

[0039] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 It is a schematic diagram of the structure of a traditional power selection circuit;

[0042] Figure 2 is a schematic diagram of the structure of a power selection circuit provided according to an embodiment of the present invention;

[0043] Figure 3 is a structural schematic diagram of another power selection circuit provided according to an embodiment of the present invention;

[0044] Figure 4 is a structural schematic diagram of another power selection circuit provided according to an embodiment of the present invention;

[0045] Figure 5 is a structural schematic diagram of another power selection circuit provided according to an embodiment of the present invention;

[0046] Figure 6 is a structural schematic diagram of another power selection circuit provided according to an embodiment of the present invention;

[0047] Figure 7 4 is a circuit schematic diagram of a power selection circuit provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the 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 the embodiments. 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.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] Figure 1 This is a schematic diagram of the structure of a traditional power selection circuit. Figure 1 The default priority of the traditional power selection circuit is that when VCC and VRF are powered at the same time, VCC is preferred. R1 and N1 form a power-on reset (POR) circuit. When the VCC voltage exceeds the flip threshold of the POR circuit, the drain voltage of N1 changes from high to low, but due to its gate-to-source voltage VGS VCC, so its drain current is large, the gate of N2 is high, and the drain voltage of N2 is also low, but because V GS The drain current is VCC, so it is large, and when VCC is powered and is about to be powered off, VPW will be powered off along with VCC. At this time, the drain voltage of N3 will also change along with VPW, causing INV4 to be unable to recognize the low level, resulting in a slower response speed. At the same time, in order to reduce power consumption, the area of ​​the resistor needs to be increased to reduce static power consumption. Therefore, the traditional power selection circuit structure has problems such as high power consumption, large area, and slow response speed.

[0051] In view of the above problems, the present invention provides a power selection circuit. Figure 2 is a schematic diagram of a power selection circuit according to an embodiment of the present invention, referring to Figure 2 The power selection circuit includes: a power tube module 10 and a power selection module 20, and the power tube module 10 is connected to the power selection module 20; the power tube module 10 includes: a first power unit 11, a second power unit 12 and a sixth power unit 13; the first power unit 11 and the second power unit 12 are connected between the first power supply voltage VRF and the voltage selection output voltage VPW, and the sixth power unit 13 is connected between the second power supply voltage VCC and the voltage selection output voltage VPW; the power selection module 20 is used to control the opening state of the first power unit 11, the second power unit 12 and the sixth power unit 13 according to the magnitude of the first power supply voltage VRF and the second power supply voltage VCC; wherein the opening state of the first power unit 11 is the same as the opening state of the second power unit 12, and the opening state of the first power unit 11 is opposite to the opening state of the sixth power unit 13; the power tube module 10 is used to select the input second power supply voltage VCC and the first power supply voltage VRF and output the voltage selection output voltage VPW.

[0052] Specifically, the input of the power selection circuit is the second power supply voltage VCC and the first power supply voltage VRF. The second power supply voltage VCC and the first power supply voltage VRF can be two voltage sources with a voltage value range of 0V-6V, for example, 1.2V, 1.8V, 3.3V, 5V, etc. The output of the power selection circuit is the voltage selection output voltage VPW, and the voltage of the voltage selection output voltage VPW can be 0V-6V. The preset priority is that when the second power supply voltage VCC and the first power supply voltage VRF are powered at the same time, the second power supply voltage VCC is preferentially selected for power supply. When the second power supply voltage VCC loses power, if the first power supply voltage VRF has power, it switches to the first power supply voltage VRF for power supply.

[0053] In the traditional power selection circuit, when the power supply is powered on quickly, backflow usually occurs, causing the unconnected power supply voltage to generate a voltage, causing the system to have a short-term error state. The power selection circuit in this embodiment can prevent the second power supply voltage VCC from backflowing to the first power supply voltage VRF by setting the first power unit 11 and the second power unit 12 between the first power supply voltage VRF and the voltage selection output voltage VPW, thereby preventing current backflow and protecting the circuit from damage.

[0054] The power selection module 20 may be a power selection circuit, which mainly outputs different voltage signals to the power tube module 10. For example, the power selection module 20 is used to output a first voltage signal V1, a second voltage signal V2, and a third voltage signal V3, and the power tube module 10 is used to select the input second power supply voltage VCC and the first power supply voltage VRF according to the first voltage signal V1, the second voltage signal V2, and the third voltage signal V3, and output the voltage selection output voltage VPW.

[0055] The on state of the first power unit 11 is the same as the on state of the second power unit 12, and the first power unit 11 and the second power unit 12 constitute an anti-backflow circuit; the on state of the first power unit 11 is opposite to the on state of the sixth power unit 13, which can ensure that when the power supply is reversed or the current direction is incorrect, the first power unit 11 and the second power unit 12 will not be turned on, thereby cutting off the connection of the subsequent circuit to prevent the current from flowing in the opposite direction, which is the so-called "backflow" phenomenon. The anti-backflow circuit is particularly suitable for application scenarios where it is necessary to prevent the power supply from being reversed or the current from flowing back, such as in electronic devices, to protect subsequent circuits and equipment from damage.

[0056] The third voltage signal V3 is input to the control end of the second power unit 12, and the high voltage of the third voltage signal V3 is the second power supply voltage VCC. When the third voltage signal VCC is written, the high voltage second power supply voltage VCC controls the second power unit 12 to shut down. The higher the potential of the control end of the second power unit 12, the better the shut-down effect of the second power unit 12, and the more obvious the anti-backflow effect. The high voltage of the third voltage signal V3 is the second power supply voltage VCC, which has a better shut-down effect on the first power unit 11 than the first power supply voltage VRF, so adding a second power unit 12 can prevent backflow.

[0057] The technical solution of the embodiment of the present invention outputs the first voltage signal, the second voltage signal and the third voltage signal through the power selection module, the power tube module selects the second power supply voltage and the first power supply voltage according to the first voltage signal, the second voltage signal and the third voltage signal and outputs the voltage selection output voltage, the power selection circuit can select the most suitable power source from multiple power inputs according to the preset priority for power supply, and can achieve low power consumption and fast response power selection. Compared with the traditional power selection circuit, the response speed is improved, the power consumption is reduced, and there will be no backflow, overshoot, and undershoot problems. In summary, the present invention solves the problem that the power selection circuit of the traditional structure usually has high power consumption or large area, and cannot respond quickly to the change of the power source, resulting in backflow, overshoot, and undershoot.

[0058] Figure 3 is a schematic diagram of the structure of another power selection circuit provided according to an embodiment of the present invention. Figure 4 is a schematic diagram of a structure of another power selection circuit provided according to an embodiment of the present invention. Figure 3 , a first end of the first power unit 11 is connected to a first power supply voltage VRF, a second end of the first power unit 11 is connected to a first end of the second power unit 12, a second end of the second power unit 12 is connected to a voltage selection output voltage VPW, a control end of the first power unit 11 is connected to a second voltage signal V2, and a control end of the second power unit 12 is connected to a third voltage signal V3;

[0059] Alternatively, refer to Figure 4 , a first end of the second power unit 12 is connected to the first power supply voltage VRF, a second end of the second power unit 12 is connected to the first end of the first power unit 11, a second end of the first power unit 11 is connected to the voltage selection output voltage VPW, a control end of the second power unit 12 is connected to the second voltage signal V2, and a control end of the first power unit 12 is connected to the third voltage signal V3;

[0060] A first end of the sixth power unit 13 is connected to the second power supply voltage VCC, a second end of the sixth power unit 13 is connected to the voltage selection output voltage VPW, and a control end of the sixth power unit 13 is connected to the first voltage signal V1.

[0061] Specifically, the positions of the second power unit 12 and the first power unit 11 can be swapped. The second power unit 12 and the first power unit 11 are arranged between the first power supply voltage VRF and the voltage selection output voltage VPW to prevent the second power supply voltage VCC from flowing back to the first power supply voltage VRF, prevent current backflow, and protect the circuit from damage.

[0062] The shut-off capability of the second power unit 12 is greater than that of the first power unit 11, and the anti-backflow effect is more obvious. The second power unit 12 is controlled by the third voltage signal V3, and the high voltage of the third voltage signal V3 is the second power supply voltage VCC. Due to the higher voltage, the shut-off effect of the second power unit 12 is better, and the backflow of the second power supply voltage VCC to the first power supply voltage VRF can be better reduced.

[0063] Figure 5 is a schematic diagram of the structure of another power selection circuit provided according to an embodiment of the present invention. Figure 6 is a schematic diagram of a structure of another power selection circuit provided according to an embodiment of the present invention. Figure 5 , the first power unit 11 includes a first MOS transistor P1, the second power unit 12 includes a second MOS transistor P2, and the sixth power unit 13 includes a sixth MOS transistor P6;

[0064] The first end of the first MOS transistor P1 is connected to the first power supply voltage VRF, the second end of the first MOS transistor P1 is connected to the first end of the second MOS transistor P2, the second end of the second MOS transistor P2 is connected to the voltage selection output voltage VPW, the control end of the first MOS transistor P1 is connected to the second voltage signal V2, and the control end of the second MOS transistor P2 is connected to the third voltage signal V3;

[0065] Alternatively, refer to Figure 6 , a first end of the second MOS transistor P2 is connected to the first power supply voltage VRF, a second end of the second MOS transistor P2 is connected to the first end of the first MOS transistor P1, a second end of the first MOS transistor P1 is connected to the voltage selection output voltage VPW, a control end of the second MOS transistor P2 is connected to the second voltage signal V2, and a control end of the first MOS transistor P1 is connected to the third voltage signal V3;

[0066] A first end of the sixth MOS transistor P6 is connected to the second power supply voltage VCC, a second end of the sixth MOS transistor P6 is connected to the voltage selection output voltage VPW, and a control end of the sixth MOS transistor P6 is connected to the first voltage signal V1.

[0067] Continue to refer Figure 5 and Figure 6 Optionally, the first MOS tube P1, the second MOS tube P2, and the sixth MOS tube P6 are P-type tubes; the first end of the first MOS tube P1 is the source, and the second end of the first MOS tube P1 is the drain; the first end of the second MOS tube P2 is the drain, and the second end of the second MOS tube P2 is the source; the first end of the sixth MOS tube P6 is the drain, and the second end of the sixth MOS tube P6 is the source.

[0068] Specifically, the positions of the second MOS transistor P2 and the first MOS transistor P1 can be swapped. The second MOS transistor P2 and the first MOS transistor P1 are arranged between the first power supply voltage VRF and the voltage selection output voltage VPW to prevent the second power supply voltage VCC from flowing back to the first power supply voltage VRF, prevent current backflow, and protect the circuit from damage.

[0069] The second MOS tube P2 has a greater turn-off capability than the first MOS tube P1, and has a more obvious anti-backflow effect. The second MOS tube P2 is controlled by the third voltage signal V3, and the high voltage of the third voltage signal V3 is the second power supply voltage VCC. Due to the higher voltage, the second MOS tube P2 has a better turn-off effect, and can better reduce the backflow of the second power supply voltage VCC to the first power supply voltage VRF.

[0070] Figure 7 is a circuit schematic diagram of a power selection circuit provided according to an embodiment of the present invention, referring to Figure 7 , Optionally, the power selection module 20 includes: a first power selection submodule 210 and a second power selection submodule 220, the first power selection submodule 210 is connected to the second power selection submodule 220;

[0071] The first power selection submodule 210 is used to output a fourth voltage signal V4 according to the first power supply voltage VRF and the second power supply voltage VCC. The second power selection submodule 220 outputs the first voltage signal V1, the second voltage signal V2 and the third voltage signal V3 in response to the fourth voltage signal V4. The power tube module 10 is used to select the input second power supply voltage VCC and the first power supply voltage VRF according to the first voltage signal V1, the second voltage signal V2 and the third voltage signal V3 and output the voltage selection output voltage VPW.

[0072] Continue to refer Figure 7 , Optionally, the first power selection submodule 210 includes: a first pull-up unit 21, a second pull-up unit 22 and a cross-coupling unit 23;

[0073] The second power selection submodule 220 includes: a third switch unit 24, a fourth switch unit 25, a fifth switch unit 26, a thirteenth switch unit 27, a fourteenth switch unit 28, and a fifteenth switch unit 29;

[0074] The first pull-up unit 21 is connected between the first power supply voltage VRF and the first end of the cross-coupling unit 23, the second pull-up unit 22 is connected between the second power supply voltage VCC and the second end of the cross-coupling unit 23, and the second end of the cross-coupling unit 23 is also connected to the control end of the thirteenth switch unit 27;

[0075] A first end of the fourth switch unit 25 is connected to the first power supply voltage VRF, and a second end of the fourth switch unit 25 is connected to a first end of the fourteenth switch unit 28 and a control end of the first power unit 11;

[0076] A first end of the fifth switch unit 26 is connected to the second power supply voltage VCC, and a second end of the fifth switch unit 26 is connected to a first end of the fifteenth switch unit 29 and a control end of the second power unit 12;

[0077] The control end of the thirteenth switch unit 27 is connected to the first power selection submodule 210, the second end of the thirteenth switch unit 27 is connected to the second end of the fourteenth switch unit 28 and then grounded, and the first end of the thirteenth switch unit 27 is connected to the control end of the fourth switch unit 25, the control end of the fourteenth switch unit 28, the control end of the fifteenth switch unit and the control end of the sixth power unit 13;

[0078] A first end of the third switch unit 24 is connected to the first power supply voltage VRF, a control end of the third switch unit 24 is connected to a control end of the fifth switch unit 26 and then grounded, and a second end of the fifteenth switch unit 29 is grounded.

[0079] Specifically, the first voltage signal V1 is 0 when the second power supply voltage VCC is powered on, and is the first power supply voltage VRF when the second power supply voltage VCC is de-powered; the second voltage signal V2 is the first power supply voltage VRF when the second power supply voltage VCC is powered on, and is 0 when the second power supply voltage VCC is de-powered; the third voltage signal V3 is the first power supply voltage VRF when the second power supply voltage VCC is powered on, and is 0 when the second power supply voltage VCC is de-powered.

[0080] When the second power supply voltage VCC is powered and the first power supply voltage VRF is powered, due to the effect of the two cross-coupled MOS transistors in the cross-coupling unit 23 and the large resistance of the first pull-up unit 21, the pull-up capability is weak. When both the second power supply voltage VCC and the first power supply voltage VRF are powered, the gate voltage of the first cross-coupled MOS transistor is high and in the linear region. The gate voltage of the second cross-coupled MOS transistor is low and in the cut-off region; therefore, the drain voltage of the second cross-coupled MOS transistor is high. If the gate voltage of the thirteenth switch unit 27 is high, the voltage of the first voltage signal V1 is low, the gates of the fourth switch unit 25 and the fourteenth switch unit 28 are low, the voltage of the second voltage signal V2 is high, the gate voltage of the fifteenth switch unit 29 is low, and the voltage of the third voltage signal V3 is high. Therefore, the voltage selection output voltage VPW is the second power supply voltage VCC voltage, which meets the preset priority.

[0081] When the second power supply voltage VCC is quickly powered off, the gate voltage of the first cross-coupled MOS tube quickly decreases and is in the cut-off region, the gate voltage of the second cross-coupled MOS tube increases, the drain voltage of the second cross-coupled MOS tube decreases, the gate voltage of the thirteenth switch unit 27 decreases, the voltage of the first voltage signal V1 increases, the gate voltages of the fourth switch unit 25 and the fourteenth switch unit 28 increase, the voltage of the second voltage signal V2 decreases, the gate voltage of the fifteenth switch unit 29 increases, the voltage of the third voltage signal V3 decreases, and the voltage selection output voltage VPW quickly switches from the second power supply voltage VCC to the first power supply voltage VRF.

[0082] When the second power supply voltage VCC is out of power, the first power supply voltage VRF is powered, but the second power supply voltage VCC is quickly powered on, at this time, the gate voltage of the first cross-coupled MOS tube quickly changes from low to high, and the gate voltage of the second cross-coupled MOS tube quickly changes from high to low, the drain voltage of the second cross-coupled MOS tube becomes high, the gate voltage of the thirteenth switch unit 27 becomes high, the voltage of the first voltage signal V1 becomes low, the voltages of the second voltage signal V2 and the third voltage signal V3 both become high, the voltage selection output voltage VPW is quickly switched to the second power supply voltage VCC voltage, and when the first power supply voltage VRF is powered alone, the first cross-coupled MOS tube is in the cut-off region, the second cross-coupled MOS tube is in the deep linear region, the thirteenth switch unit 27 is in the cut-off region, the fourteenth switch unit 28 is in the deep linear region, and the fifteenth switch unit 29 is in the deep linear region. Therefore, the static power consumption is only the second cross-coupled MOS tube, the fourteenth switch unit 28 and the fifteenth switch unit 29 in the deep linear region, and the current is about nA level.

[0083] When the second power supply voltage VCC is used alone for power supply, the first cross-coupled MOS transistor is in the deep linear region, the second cross-coupled MOS transistor is in the cut-off region, the thirteenth switch unit 27 is in the deep linear region, the fourteenth switch unit 28 is in the cut-off region, and the fifteenth switch unit 29 is in the cut-off region. Therefore, the static power consumption is only the first cross-coupled MOS transistor and the thirteenth switch unit 27 in the deep linear region, and the current is about nA level.

[0084] When the second power supply voltage VCC and the first power supply voltage VRF are supplied simultaneously, the first cross-coupled MOS transistor is in a deep linear region, the second cross-coupled MOS transistor is in a cut-off region, the thirteenth switch unit 27 is in a deep linear region, the fourteenth switch unit 28 is in a cut-off region, and the fifteenth switch unit 29 is in a cut-off region. Therefore, the static power consumption is only the first cross-coupled MOS transistor and the thirteenth switch unit 27 in the deep linear region, and the current is about nA level. Compared with the traditional power selection circuit, the response speed is improved and the power consumption is reduced.

[0085] Continue to refer Figure 7 Optionally, the first pull-up unit 21 includes a first pull-up resistor R1, and the second pull-up unit 22 includes a second pull-up resistor R2; the first pull-up resistor R1 is connected between the first power supply voltage VRF and the first end of the cross-coupling unit 23, and the second pull-up resistor R2 is connected between the second power supply voltage VCC and the second end of the cross-coupling unit 23.

[0086] Continue to refer Figure 7 Optionally, the resistance of the first pull-up resistor R1 is K times the resistance of the second pull-up resistor R2, where K is an integer greater than 1.

[0087] Specifically, Figure 7 The resistance of the first pull-up resistor R1 can be twice the resistance of the second pull-up resistor R2. The resistance of the first pull-up resistor R1 can be set to K times the resistance of the second pull-up resistor R2 according to actual needs, and the embodiment of the present invention does not limit the K value.

[0088] Continue to refer Figure 7 Optionally, the cross-coupling unit 23 includes: a first switch subunit 231 and a second switch subunit 232; the first end of the first switch subunit 231 is connected to the control end of the second switch subunit 232 and the first pull-up unit 21, the first end of the second switch subunit 232 is connected to the control end of the first switch subunit 231, the second pull-up unit 22 and the control end of the thirteenth switch unit 27, and the second end of the first switch subunit 231 is connected to the second end of the second switch subunit 232 and then grounded.

[0089] Specifically, the cross-coupling unit 23 may be a cross-coupling transistor, which realizes various functions, such as an amplifier, a switch, a multiplexer, and a memory. Different functions can be realized by adjusting the gate voltage of the cross-coupling transistor and the input mode of the selection signal.

[0090] Continue to refer Figure 7 Optionally, the first switch subunit 231 includes a first NMOS tube N1, and the second switch subunit 232 includes a second NMOS tube N2; the first end of the first NMOS tube N1 is connected to the control end of the second NMOS tube N2 and the first pull-up unit 21, the first end of the second NMOS tube N2 is connected to the control end of the first NMOS tube N1, the second pull-up unit 22 and the control end of the thirteenth switch unit 27, and the second end of the first NMOS tube N1 is connected to the second end of the second NMOS tube N2 and then grounded.

[0091] Continue to refer Figure 7 Optionally, the relationship between the sizes of the first NMOS transistor N1 and the second NMOS transistor N2 is expressed as follows:

[0092]

[0093] Among them, W N1 is the width of the first NMOS tube N1, L N1 is the length of the first NMOS tube N1, W N2 is the width of the second NMOS tube N2, L N2 is the length of the second NMOS tube N2.

[0094] Continue to refer Figure 7 Optionally, the third switch unit 24 includes a third MOS transistor P3, the fourth switch unit 25 includes a fourth MOS transistor P4, and the fifth switch unit 26 includes a fifth MOS transistor P5; the thirteenth switch unit 27 includes a thirteenth MOS transistor N3, the fourteenth switch unit 28 includes a fourteenth MOS transistor N4, and the fifth switch unit 29 includes a fifteenth MOS transistor N5; the second end of the cross-coupling unit 23 is connected to the control end of the thirteenth MOS transistor N3, the second end of the thirteenth MOS transistor N3 is connected to the second end of the fourteenth MOS transistor N4 and then grounded, and the first end of the fourteenth MOS transistor N4 is connected to the second end of the fourth MOS transistor P4 and the control end of the first MOS transistor P1 The first end of the fourth MOS tube P4 is connected to the first power supply voltage VRF, the first end of the thirteenth MOS tube N3 is connected to the control end of the sixth MOS tube P6, the control end of the fifteenth MOS tube N5 and the second end of the third MOS tube P3 are connected, the control end of the third MOS tube P3 is connected to the control end of the fifth MOS tube P5 and then grounded, the second end of the fifteenth MOS tube N5 is grounded, the first end of the fifteenth MOS tube N5 is connected to the second end of the fifth MOS tube P5 and the control end of the second MOS tube P2, the first end of the third MOS tube P3 is connected to the first power supply voltage VRF, and the first end of the fifth MOS tube P5 is connected to the second power supply voltage VCC.

[0095] Continue to refer Figure 7 Optionally, the third MOS tube P3, the fourth MOS tube P4, and the fifth MOS tube P5 are P-type tubes, and the thirteenth MOS tube N3, the fourteenth MOS tube N4, and the fifteenth MOS tube N5 are N-type tubes.

[0096] Continue to refer Figure 7 , when the first voltage signal V1 is in the second power supply voltage VCC, the thirteenth MOS tube N3 and the third MOS tube P3 are turned on, and the potential of the first voltage signal V1 is 0; when the second power supply voltage VCC is not in the second power supply voltage, the thirteenth MOS tube N3 is turned off, the third MOS tube P3 is turned on, and the potential of the first voltage signal V1 is the first power supply voltage VRF;

[0097] When the second power supply voltage VCC is powered, the fourth MOS transistor P4 and the fourteenth MOS transistor N4 are turned on, and the potential of the second voltage signal V2 is the first power supply voltage VRF. When the second power supply voltage VCC is not powered, the fourteenth MOS transistor N4 is turned on, the fourth MOS transistor P4 is turned off, and the potential of the second voltage signal V2 is 0.

[0098] When the second power supply voltage VCC is powered, the fifth MOS tube P5 and the fifteenth MOS tube N5 are turned on, and the potential of the third voltage signal V3 is the first power supply voltage VRF. When the second power supply voltage VCC is not powered, the fifteenth MOS tube N5 is turned off, the fifth MOS tube P5 is turned on, and the potential of the third voltage signal V3 is 0.

[0099] Specifically, the gate of the first MOS transistor P1 is connected to the output second voltage signal V2, the source of the first MOS transistor P1 is connected to the first power supply voltage VRF, and the drain of the first MOS transistor P1 is connected to the drain of the second MOS transistor P2. The gate of the second MOS transistor P2 is connected to the output third voltage signal V3, and the source of the second MOS transistor P2 is connected to the source of the sixth MOS transistor P6 and connected to the voltage selection output voltage VPW. The drain of the sixth MOS transistor P6 is connected to the second power supply voltage VCC, the gate of the sixth MOS transistor P6 is connected to the output voltage signal V1, the upper end of the first pull-up resistor R1 is connected to the first power supply voltage VRF, the lower end of the first pull-up resistor R1 is connected to the drain of the first MOS transistor N1 and the gate of the second NMOS transistor N2, the gate of the first MOS transistor N1 is connected to the lower end of the second pull-up resistor R2 and the drain of the second NMOS transistor N2, and outputs a fourth voltage signal V4 (mainly controlling the opening and closing of the thirteenth MOS transistor N3), the source of the second NMOS transistor N2 is grounded, the source of the first MOS transistor N1 is grounded, the upper end of the first pull-up resistor R1 is connected to the second power supply voltage VCC, the lower end of the first pull-up resistor R1 is connected to the gate of the thirteenth MOS transistor N3, the source of the thirteenth MOS transistor N3 is connected to the ground, the drain of the thirteenth MOS transistor N3 is connected to the drain of the third MOS transistor P3, the gate of the fifteenth MOS transistor N5, the gate of the fourth MOS transistor P4, the gate of the fourteenth MOS transistor N4 and the output first voltage signal The gate of the third MOS tube P3 is connected to the ground, the source of the third MOS tube P3 is connected to the first power supply voltage VRF, the drain of the third MOS tube P3 is connected to the output first voltage signal V1 and the drain of the thirteenth MOS tube N3, the source of the fifth MOS tube P5 is connected to the second power supply voltage VCC, the gate of the fifth MOS tube P5 is connected to the ground, the drain of the fifth MOS tube P5 is connected to the drain of the fifteenth MOS tube N5 and the output third voltage signal V3, the gate of the fourth MOS tube P4 is connected to the gate of the fourteenth MOS tube N4 and the output first voltage signal V1, the source of the fourth MOS tube P4 is connected to the first power supply voltage VRF, the drain of the fourth MOS tube P4 is connected to the output second voltage signal V2 and the drain of the fourteenth MOS tube N4, the gate of the fourteenth MOS tube N4 is connected to the gate of the fourth MOS tube P4, the drain of the fourteenth MOS tube N4 is connected to the output second voltage signal V2, and the source of the fourteenth MOS tube N4 is connected to the ground.

[0100] When the second power supply voltage VCC is powered and the first power supply voltage VRF is powered, since the first NMOS tube N1 and the second NMOS tube N2 are cross-coupled tubes, and the resistance of the first pull-up resistor R1 is large, the pull-up capability is weak, when both the second power supply voltage VCC and the first power supply voltage VRF are powered, the gate voltage of the first NMOS tube N1 is high and in the linear region. The gate voltage of the second NMOS tube N2 is low and in the cut-off region; therefore, the drain voltage of the second NMOS tube N2 is high, the gate voltage of the thirteenth MOS tube N3 is high, the voltage of the first voltage signal V1 is low, the gates of the fourth MOS tube P4 and the fourteenth MOS tube N4 are low, the voltage of the second voltage signal V2 is high, the gate voltage of the fifteenth MOS tube N5 is low, and the voltage of the third voltage signal V3 is high, therefore, the voltage selection output voltage VPW is the second power supply voltage VCC voltage, which meets the preset priority.

[0101] When the second power supply voltage VCC is quickly powered off, the gate voltage of the first NMOS tube N1 quickly decreases and is in the cut-off region, the gate voltage of the second NMOS tube N2 increases, the drain voltage of the second NMOS tube N2 decreases, the gate voltage of the thirteenth MOS tube N3 decreases, the voltage of the first voltage signal V1 increases, the gate voltages of the fourth MOS tube P4 and the fourteenth MOS tube N4 increase, the voltage of the second voltage signal V2 decreases, the gate voltage of the fifteenth MOS tube N5 increases, the voltage of the third voltage signal V3 decreases, and the voltage selection output voltage VPW quickly switches from the second power supply voltage VCC to the first power supply voltage VRF.

[0102] When the second power supply voltage VCC is out of power, the first power supply voltage VRF is powered, but the second power supply voltage VCC is quickly powered on, at this time, the gate voltage of the first NMOS tube N1 quickly changes from low to high, and the gate voltage of the second NMOS tube N2 quickly changes from high to low, the drain voltage of the second NMOS tube N2 becomes high, the gate voltage of the thirteenth MOS tube N3 becomes high, the voltage of the first voltage signal V1 becomes low, the voltages of the second voltage signal V2 and the third voltage signal V3 both become high, the voltage selection output voltage VPW quickly switches to the second power supply voltage VCC voltage, and when the first power supply voltage VRF is powered alone, the first NMOS tube N1 is in the cut-off region, the second NMOS tube N2 is in the deep linear region, the thirteenth MOS tube N3 is in the cut-off region, the fourteenth MOS tube N4 is in the deep linear region, and the fifteenth MOS tube N5 is in the deep linear region. Therefore, the static power consumption is only the second NMOS tube N2, the fourteenth MOS tube N4 and the fifteenth MOS tube N5 in the deep linear region, and the current is about nA level.

[0103] When the second power supply voltage VCC is used alone for power supply, the first NMOS transistor N1 is in the deep linear region, the second NMOS transistor N2 is in the cut-off region, the thirteenth MOS transistor N3 is in the deep linear region, the fourteenth MOS transistor N4 is in the cut-off region, and the fifteenth MOS transistor N5 is in the cut-off region. Therefore, the static power consumption is only the first NMOS transistor N1 and the thirteenth MOS transistor N3 in the deep linear region, and the current is about nA level.

[0104] When the second power supply voltage VCC and the first power supply voltage VRF are supplied simultaneously, the first NMOS tube N1 is in the deep linear region, the second NMOS tube N2 is in the cut-off region, the thirteenth MOS tube N3 is in the deep linear region, the fourteenth MOS tube N4 is in the cut-off region, and the fifteenth MOS tube N5 is in the cut-off region. Therefore, the static power consumption is only the first NMOS tube N1 and the thirteenth MOS tube N3 in the deep linear region, and the current is about nA level. Compared with the traditional power selection circuit, the response speed is improved and the power consumption is reduced.

[0105] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A power selection circuit, It is characterized in that include: A power tube module and a power selection module, wherein the power tube module is connected to the power selection module; The power tube module includes: a first power unit, a second power unit and a sixth power unit; The first power unit and the second power unit are connected between a first power supply voltage and a voltage selection output voltage, and the sixth power unit is connected between a second power supply voltage and the voltage selection output voltage; The power selection module is used to control the on-states of the first power unit, the second power unit and the sixth power unit according to the magnitudes of the first power voltage and the second power voltage; wherein the on-state of the first power unit is the same as the on-state of the second power unit, and the on-state of the first power unit is opposite to the on-state of the sixth power unit; The power tube module is used to select the second power supply voltage and the first power supply voltage that are input and then output a voltage selection output voltage.

2. The power selection circuit according to claim 1, It is characterized in that The first end of the first power unit is connected to a first power supply voltage, the second end of the first power unit is connected to a first end of the second power unit, the second end of the second power unit is connected to a voltage selection output voltage, the control end of the first power unit is connected to a second voltage signal, and the control end of the second power unit is connected to a third voltage signal; Alternatively, the first end of the second power unit is connected to the first power supply voltage, the second end of the second power unit is connected to the first end of the first power unit, the second end of the first power unit is connected to the voltage selection output voltage, the control end of the second power unit is connected to the second voltage signal, and the control end of the first power unit is connected to the third voltage signal; The first end of the sixth power unit is connected to the second power supply voltage, the second end of the sixth power unit is connected to the voltage selection output voltage, and the control end of the sixth power unit is connected to the first voltage signal.

3. The power selection circuit according to claim 2, It is characterized in that The first power unit includes a first MOS tube, the second power unit includes a second MOS tube, and the sixth power unit includes a sixth MOS tube; The first end of the first MOS transistor is connected to the first power supply voltage, the second end of the first MOS transistor is connected to the first end of the second MOS transistor, the second end of the second MOS transistor is connected to the voltage selection output voltage, the control end of the first MOS transistor is connected to the second voltage signal, and the control end of the second MOS transistor is connected to the third voltage signal; Alternatively, the first end of the second MOS transistor is connected to the first power supply voltage, the second end of the second MOS transistor is connected to the first end of the first MOS transistor, the second end of the first MOS transistor is connected to the voltage selection output voltage, the control end of the second MOS transistor is connected to the second voltage signal, and the control end of the first MOS transistor is connected to the third voltage signal; The first end of the sixth MOS tube is connected to the second power supply voltage, the second end of the sixth MOS tube is connected to the voltage selection output voltage, and the control end of the sixth MOS tube is connected to the first voltage signal.

4. The power selection circuit according to claim 3, It is characterized in that The power selection module includes: a first power selection submodule and a second power selection submodule, wherein the first power selection submodule is connected to the second power selection submodule; The first power selection submodule is used to output a fourth voltage signal according to the first power selection voltage and the second power selection voltage, the second power selection submodule outputs the first voltage signal, the second voltage signal and the third voltage signal in response to the fourth voltage signal, and the power tube module is used to select the input second power supply voltage and the first power supply voltage according to the first voltage signal, the second voltage signal and the third voltage signal and output the voltage selection output voltage.

5. The power selection circuit according to claim 4, It is characterized in that The first power selection submodule includes: a first pull-up unit, a second pull-up unit and a cross-coupling unit; The second power selection submodule includes: a third switch unit, a fourth switch unit, a fifth switch unit, a thirteenth switch unit, a fourteenth switch unit and a fifteenth switch unit; The first pull-up unit is connected between the first power supply voltage and the first end of the cross-coupling unit, the second pull-up unit is connected between the second power supply voltage and the second end of the cross-coupling unit, and the second end of the cross-coupling unit is also connected to the control end of the thirteenth switch unit; The first end of the fourth switch unit is connected to the first power supply voltage, and the second end of the fourth switch unit is connected to the first end of the fourteenth switch unit and the control end of the first power unit; The first end of the fifth switch unit is connected to the second power supply voltage, and the second end of the fifth switch unit is connected to the first end of the fifteenth switch unit and the control end of the second power unit; The control end of the thirteenth switch unit is connected to the first power selection submodule, the second end of the thirteenth switch unit is connected to the second end of the fourteenth switch unit and then grounded, and the first end of the thirteenth switch unit is connected to the control end of the fourth switch unit, the control end of the fourteenth switch unit, the control end of the fifteenth switch unit, and the control end of the sixth power unit; The first end of the third switch unit is connected to the first power supply voltage, the control end of the third switch unit is connected to the control end of the fifth switch unit and then grounded, and the second end of the fifteenth switch unit is grounded.

6. The power selection circuit according to claim 5, It is characterized in that The first pull-up unit includes a first pull-up resistor, and the second pull-up unit includes a second pull-up resistor; The first pull-up resistor is connected between the first power supply voltage and the first end of the cross-coupling unit, and the second pull-up resistor is connected between the second power supply voltage and the second end of the cross-coupling unit.

7. The power selection circuit according to claim 5, It is characterized in that The cross-coupling unit comprises: a first switch sub-unit and a second switch sub-unit; The first end of the first switch subunit is connected to the control end of the second switch subunit and the first pull-up unit, the first end of the second switch subunit is connected to the control end of the first switch subunit, the second pull-up unit and the control end of the thirteenth switch unit, and the second end of the first switch subunit is connected to the second end of the second switch subunit and then grounded.

8. The power selection circuit according to claim 7, It is characterized in that The first switch subunit includes a first NMOS transistor, and the second switch subunit includes a second NMOS transistor; The first end of the first NMOS tube is connected to the control end of the second NMOS tube and the first pull-up unit, the first end of the second NMOS tube is connected to the control end of the first NMOS tube, the second pull-up unit and the control end of the thirteenth switch unit, and the second end of the first NMOS tube is connected to the second end of the second NMOS tube and then grounded.

9. The power selection circuit according to claim 8, It is characterized in that The relationship between the sizes of the first NMOS tube and the second NMOS tube is expressed as follows: Among them, W N1 is the width of the first NMOS tube, L N1 is the length of the first NMOS tube, W N2 is the width of the second NMOS tube, L N2 is the length of the second NMOS tube.

10. The power selection circuit according to claim 5, It is characterized in that The third switch unit includes a third MOS transistor, the fourth switch unit includes a fourth MOS transistor, and the fifth switch unit includes a fifth MOS transistor; The thirteenth switch unit includes a thirteenth MOS tube, the fourteenth switch unit includes a fourteenth MOS tube, and the fifth switch unit includes a fifteenth MOS tube; The second end of the cross-coupling unit is connected to the control end of the thirteenth MOS tube, the second end of the thirteenth MOS tube is connected to the second end of the fourteenth MOS tube and then grounded, the first end of the fourteenth MOS tube is connected to the second end of the fourth MOS tube and the control end of the first MOS tube, the first end of the fourth MOS tube is connected to the first power supply voltage, the first end of the thirteenth MOS tube is connected to the control end of the sixth MOS tube, the control end of the fifteenth MOS tube is connected to the second end of the third MOS tube, the control end of the third MOS tube is connected to the control end of the fifth MOS tube and then grounded, the second end of the fifteenth MOS tube is grounded, the first end of the fifteenth MOS tube is connected to the second end of the fifth MOS tube and the control end of the second MOS tube, the first end of the third MOS tube is connected to the first power supply voltage, and the first end of the fifth MOS tube is connected to the second power supply voltage.

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