Level shift circuit, control method thereof, and electronic device

Abstract

The application discloses a level transfer circuit, a control method thereof and electronic equipment, and relates to the technical field of integrated circuits.The circuit comprises a logic control module, an AC-DC coupling module and an inverting output module.In the logic control module, a first signal input end is connected with an input signal source, and a second signal input end is connected with an enable signal source.The AC-DC coupling module comprises a DC coupling unit and an AC coupling unit.In the DC coupling unit, a first control input end is connected with a first control output end, and a second control input end is connected with a second control output end.In the AC coupling unit, an AC coupling input end is connected with the first control output end, an AC coupling output end is connected with a DC coupling output end.In the inverting output module, an inverting input end is connected with the DC coupling output end, and an inverting output end is used for outputting a target level transfer signal.The circuit can realize low-delay, high-speed and good-duty-ratio level transfer functions for AC signals and DC signals.

Description

Technical Field

[0001] This application relates to the field of integrated circuit technology, and in particular to a level shifting circuit, its control method, and an electronic device. Background Technology

[0002] Level shifting circuits have wide applications in integrated circuits. They are a crucial bridge in electronic systems, solving the problem of different circuit modules or devices being unable to communicate directly due to different operating voltages.

[0003] In related technologies, common level-shifting circuits include two NMOS transistors (M1 and M2), two PMOS transistors (M3 and M4), and two inverters (inv1 and inv2). A drawback of this circuit is that if the two NMOS transistors (M1 and M2) are not large enough, the conducting NMOS transistors may not be driven strongly enough to pull down the signal vop_1 or von_1, causing the level-shifting function to fail. If the two NMOS transistors (M1 and M2) are very large, parasitic capacitance will limit the switching speed of the signal vop_1 or von_1; therefore, this circuit structure can generally only achieve a speed of a few hundred MHz. Currently, common high-speed level-shifting circuits are basically based on... Figure 1 Improvements to the circuit architecture of the level shifting circuit shown, such as connecting PMOS or NMOS transistors in series, using low-voltage NMOS transistors, and adding a bias voltage, have improved the level shifting speed to some extent, but it is still not fast enough, and problems such as long delay and duty cycle misalignment remain unresolved. Therefore, how to achieve a level shifting circuit that combines low delay, high speed, and good duty cycle is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a level shifting circuit, its control method, and an electronic device, which can achieve low-delay, high-speed, and good duty cycle level shifting functions for both AC and DC signals by combining an AC coupling unit and a DC coupling unit.

[0005] In a first aspect, embodiments of this application provide a level shifting circuit, including:

[0006] The logic control module includes a first signal input terminal, a second signal input terminal, a first control output terminal, a second control output terminal, and a first power input terminal; the first signal input terminal is connected to an input signal source, the second signal input terminal is connected to an enable signal source, and the first power input terminal is connected to a first power source;

[0007] The AC-DC coupling module comprises: a DC coupling unit and an AC coupling unit; wherein the DC coupling unit comprises a first control input end, a second control input end, a DC coupling output end and a second power input end; the first control input end is connected with the first control output end, the second control input end is connected with the second control output end, and the second power input end is connected with a second power supply; the AC coupling unit comprises an AC coupling input end and an AC coupling output end; the AC coupling input end is connected with the first control output end; and the AC coupling output end is connected with the DC coupling output end.

[0008] The inverting output module comprises an inverting input end, an inverting output end and a third power input end; the inverting input end is connected with the DC coupling output end, the inverting output end is used for outputting a target level shift signal, and the third power input end is connected with the second power supply.

[0009] In a second aspect, an embodiment of the present application provides a control method of a level shift circuit, applied to the level shift circuit as described in the first aspect, and the level shift circuit comprises: a logic control module, an AC-DC coupling module and an inverting output module; the AC-DC coupling module comprises: a DC coupling unit and an AC coupling unit.

[0010] The method comprises:

[0011] When the enable signal is a high level, the logic control module performs logic judgment processing according to the enable signal and an input signal, outputs a first logic control signal and a second logic control signal to the AC-DC coupling module, determines the on-off state of a branch in which the AC coupling unit is located, controls the DC coupling unit to perform routing voltage division processing, and outputs a coupling signal to the inverting output module; wherein the input signal is a DC signal or an AC signal.

[0012] The inverting output module performs inverting processing on the coupling signal and outputs a target level shift signal.

[0013] In a third aspect, an embodiment of the present application provides an electronic device comprising the level shift circuit as described in the first aspect.

[0014] The embodiments of the present application comprise:

[0015] The level transfer circuit comprises a logic control module, an AC-DC coupling module and an inverting output module. The AC-DC coupling module comprises a DC coupling unit and an AC coupling unit. The level transfer circuit realizes the level transfer function of the input AC signal and DC signal through AC coupling and DC coupling. In the working process of the level transfer circuit, when the enable signal is high, the logic control module performs logic judgment processing according to the enable signal and the input signal, and outputs the first logic control signal and the second logic control signal to the AC-DC coupling module, determines the on-off state of the branch where the AC coupling unit is located, controls the DC coupling unit to perform routing voltage division processing, and outputs the coupling signal to the inverting output module. The input signal is a DC signal or an AC signal. Then, the inverting output module inverts the coupling signal, and outputs the target level transfer signal. In this way, the level transfer function of low delay, high speed and good duty cycle can be realized for the input DC signal and AC signal. That is to say, the embodiment of the application can realize the level transfer function of low delay, high speed and good duty cycle for the AC signal and the DC signal by combining the AC coupling unit and the DC coupling unit. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic diagram of a common level shift circuit in the prior art;

[0017] Figure 2 is a structural schematic diagram of a common AC coupling level shift circuit in the prior art;

[0018] Figure 3 is a structural schematic diagram of a level transfer circuit provided by an embodiment of the application;

[0019] Figure 4 is a specific structural schematic diagram of a level transfer circuit provided by an embodiment of the application;

[0020] Figure 5 is a step flowchart of a control method of a level transfer circuit provided by an embodiment of the application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the application clearer, the application is further described in detail below with reference to the drawings and embodiments.

[0022] It should be noted that although the logical order is shown in the flowchart in the description of the present application, in some cases, the steps shown or described can be performed in an order different from that in the flowchart. In the description of the present application, several meanings are one or more, and multiple meanings are two or more. The description of "first", "second" is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the sequence of indicated technical features.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0024] Firstly, some terms involved in the present application are explained:

[0025] VCC: derived from BJT circuit, representing the supply voltage of collector (such as +5V, +12V).

[0026] VDD: derived from MOSFET circuit, representing the supply voltage of drain (such as +3.3V, +1.8V).

[0027] The present application provides a level shift circuit 100, a control method of the level shift circuit 100 and an electronic device, and relates to the technical field of integrated circuits. The circuit comprises a logic control module 110, an AC-DC coupling module 120 and an inverting output module 130. In the logic control module 110, a first signal input end 111 is connected with an input signal Vin source, and a second signal input end 112 is connected with an enable signal source. The AC-DC coupling module 120 comprises a DC coupling unit 121 and an AC coupling unit 122. In the DC coupling unit 121, a first control input end 121A is connected with a first control output end 113, and a second control input end 121B is connected with a second control output end 114. In the AC coupling unit 122, an AC coupling input end 122A is connected with the first control output end 113, an AC coupling output end 122B is connected with a DC coupling output end 121C. In the inverting output module 130, an inverting input end 131 is connected with the DC coupling output end 121C, and an inverting output end 132 is used for outputting a target level shift signal Vout. The level shift function of low delay, high speed and good duty cycle can be realized for AC signal and DC signal.

[0028] The embodiments of the present application are further described below in conjunction with the drawings.

[0029] In the first aspect, as Figure 3As shown, the embodiment of the present application provides a level shift circuit 100, comprising: a logic control module 110, an AC-DC coupling module 120 and an inverting output module 130, wherein the logic control module 110, the AC-DC coupling module 120 and the inverting output module 130 are connected in sequence. The specific connection relationship between the logic control module 110, the AC-DC coupling module 120 and the inverting output module 130 is described as follows.

[0030] Specifically, the logic control module 110 comprises a first signal input end 111, a second signal input end 112, a first control output end 113, a second control output end 114 and a first power input end; the first signal input end 111 is connected with an input signal Vin source, the second signal input end 112 is connected with an enable signal source, and the first power input end is connected with a first power supply VDD.

[0031] Specifically, the AC-DC coupling module 120 comprises: a DC coupling unit 121 and an AC coupling unit 122; wherein the DC coupling unit 121 comprises a first control input end 121A, a second control input end 121B, a DC coupling output end 121C and a second power input end; the first control input end 121A is connected with the first control output end 113, the second control input end 121B is connected with the second control output end 114, and the second power input end is connected with a second power supply VCC; the AC coupling unit 122 comprises an AC coupling input end 122A and an AC coupling output end 122B; the AC coupling input end 122A is connected with the first control output end 113; the AC coupling output end 122B is connected with the DC coupling output end 121C.

[0032] Specifically, the inverting output module 130 comprises an inverting input end 131, an inverting output end 132 and a third power input end; the inverting input end 131 is connected with the DC coupling output end 121C, the inverting output end 132 is used for outputting a target level shift signal Vout, and the third power input end is connected with the second power supply VCC.

[0033] Further, the functions realized by each circuit module in the level shift circuit 100 are further described.

[0034] Specifically, the enable signal source is used for outputting an enable signal en, and the enable signal en can be a high level or a low level.

[0035] Specifically, the input signal Vin source is used for generating an input signal Vin, and the input signal Vin can be an AC signal or a DC signal. It can be understood that the level shift circuit 100 is applied to different integrated circuit systems, and then the circuit module serving as the input signal Vin source is different, and therefore, the circuit module serving as the input signal Vin source is not specifically limited in the present application.

[0036] Specifically, the first power supply VDD is configured to output a VDD power supply voltage, and provide power required by the logic control module 110 for operation; and the second power supply VCC is configured to output a VCC power supply voltage, and provide power required by the AC-DC coupling module 120 and the inverting output module 130 for operation.

[0037] Specifically, in the logic control module 110, the first signal input end 111 is configured to receive an input signal Vin, and the second signal input end 112 is configured to receive an enable signal en; the logic control module 110 is configured to: perform logic judgment processing according to the enable signal en and the input signal Vin, output a first logic control signal vinp and a second logic control signal vinn to the AC-DC coupling module 120, so as to control the on-off state of the branch in which the AC coupling unit 122 is located, and control the DC coupling unit 121 to perform routing voltage division processing, and output a coupling signal to the inverting output module 130.

[0038] Specifically, in the AC-DC coupling module 120, the first control input end 121A is configured to receive the first logic control signal vinp output by the logic control module 110, and the second control input end 121B is configured to receive the second logic control signal vinn output by the logic control module 110; then, the on-off state of the branch in which the AC coupling unit 122 is located is determined according to the first logic control signal vinp, and the DC coupling unit 121 is controlled to perform routing voltage division processing according to the first logic control signal vinp and the second logic control signal vinn, and output a coupling signal to the inverting output module 130.

[0039] Specifically, in the inverting output module 130, the inverting input end 131 is configured to receive the coupling signal output by the AC-DC coupling module 120, and the inverting output module 130 is configured to perform inverting processing on the coupling signal to obtain a target level shift signal Vout; and the inverting output end 132 is configured to output the target level shift signal Vout.

[0040] Further, the specific structure of the logic control module 110, the AC-DC coupling module 120 and the inverting output module 130 is described as follows.

[0041] According to some embodiments of the present application, as shown in Figure 4 The logic control module 110 includes: a NAND logic gate nand2, a first inverter inv1, and an AND logic gate and2. Further, referring to Figure 3 and Figure 4 The specific connection relationship between the NAND logic gate nand2, the first inverter inv1, and the AND logic gate and2 is further described.

[0042] Specifically, a first input end of the NAND logic gate nand2 is connected with a source of an input signal Vin, and a second input end of the NAND logic gate nand2 is connected with a source of an enable signal en; the input signal Vin is used to generate the input signal Vin; the enable signal en is used to generate the enable signal en; an input end of the first inverter inv1 is connected with an output end of the NAND logic gate nand2; an output end of the first inverter inv1 is a first control output end 113, and the first control output end 113 is connected with an alternating current (AC) coupling input end 122A; a first input end of the AND logic gate and2 is connected with the output end of the NAND logic gate nand2; a second input end of the AND logic gate and2 is connected with the source of the enable signal en; and an output end of the AND logic gate and2 is a second control output end 114, and the second control output end 114 is connected with a second control input end 121B of the direct current (DC) coupling unit 121.

[0043] Further, the functions of the NAND logic gate nand2, the first inverter inv1 and the AND logic gate and2 are further described.

[0044] Specifically, the NAND logic gate nand2 is one of the most basic general-purpose logic gates in digital circuits, and the core function thereof is "AND first and NOT then". The logical expression of the NAND logic gate nand2 is: The logical operation performed by the NAND logic gate nand2 is: performing an AND operation on the input A and the input B, and then taking the NOT of the AND operation result to obtain the output Y. Specifically, in the embodiment of the present application, example one: when the enable signal en is at a high level, the input signal Vin is a direct current signal, and the direct current signal is at a high level (i.e. 1), the NAND logic gate nand2 outputs a low level (i.e. 0). Example two: when the enable signal en is at a high level, the input signal Vin is a direct current signal, and the direct current signal is at a low level (i.e. 0), the NAND logic gate nand2 outputs a high level (i.e. 1). Example three: when the enable signal en is at a low level, the NAND logic gate nand2 outputs a high level (i.e. 1) regardless of whether the direct current signal is at a high level or a low level.

[0045] Specifically, the logical expression of the first inverter inv1 is: The logical operation performed by the first inverter inv1 is: taking the inverse of the input A to obtain the output Y. Specifically, in the embodiment of the present application, example one: when the NAND logic gate nand2 outputs a high level to the first inverter inv1, the first inverter inv1 takes the inverse of the high level, and outputs a first logic control signal vinp at a low level. Example two: when the NAND logic gate nand2 outputs a low level to the first inverter inv1, the first inverter inv1 takes the inverse of the low level, and outputs the first logic control signal vinp at a high level.

[0046] Specifically, the logical expression of the AND logic gate and2 is: The logical operation performed by the AND gate and2 is: performing logical AND operation on input A and input B to obtain output Y. Specifically, in the embodiments of the present application, example one: when the enable signal en is high (i.e. 1) and the NAND gate nand2 outputs high (i.e. 1), the second logic control signal vinn output by the AND gate and2 is high (i.e. 1). Example two: when the enable signal en is high (i.e. 1) and the NAND gate nand2 outputs low (i.e. 0), the second logic control signal vinn output by the AND gate and2 is high (i.e. 0). Example three: when the enable signal en is low (i.e. 0), the second logic control signal vinn output by the AND gate and2 is low regardless of whether the direct current signal is high or low.

[0047] In the logic control module 110 provided by the embodiments of the present application, through the cooperation between the NAND gate nand2, the first inverter inv1 and the AND gate and2, the first logic control signal vinn and the second logic control signal vinn can be output by performing logical judgment processing according to the enable signal en and the input signal Vin, so as to realize reliable control of the AC-DC coupling module 120.

[0048] According to some embodiments of the present application, the AC coupling unit 122 includes: a coupling capacitor C, one end of the coupling capacitor C being an AC coupling input end 122A, and the other end of the coupling capacitor C being an AC coupling output end 122B; the AC coupling input end 122A is connected with the first control output end 113 of the first inverter inv1; and the AC coupling output end 122B is connected with the DC coupling output end 121C of the DC coupling unit 121.

[0049] It can be understood that the coupling capacitor C has the function of blocking direct current and passing alternating current, i.e. blocking direct current signals and allowing alternating current signals to pass. According to the AC coupling function of the coupling capacitor C, two examples are given to illustrate the specific process of determining the on-off state of the branch in which the AC coupling unit 122 is located according to the first logic control signal vinn. Example one: when the enable signal en is high and the input signal Vin is a direct current signal, the first logic control signal vinn does not jump, but remains high or low, so that the branch in which the AC coupling unit 122 (i.e. the coupling capacitor C) is located is disconnected. Example two: when the enable signal en is high and the input signal Vin is an alternating current signal, the first logic control signal vinn jumps from low to high, so that the branch in which the AC coupling unit 122 (i.e. the coupling capacitor C) is located is turned on.

[0050] According to some embodiments of the present application, the direct current coupling unit 121 comprises: a voltage dividing unit, a first switch tube Q1, and a second switch tube Q2; further, the specific connection relationship between the voltage dividing unit, the first switch tube Q1, and the second switch tube Q2 is further described.

[0051] Specifically, the voltage dividing unit comprises: a first resistor R1, a second resistor R2, and a third resistor R3; one end of the third resistor R3 is connected with the second power supply VCC as a second power supply VCC end, and the other end of the third resistor R3 is connected with the inverting input terminal 131 as a direct current coupling output terminal 121C.

[0052] Specifically, the gate of the first switch tube Q1 is connected with the output terminal (i.e., the second control output terminal 114) of the logic gate and2, the source of the first switch tube Q1 is grounded, and the drain of the first switch tube Q1 is connected between the alternating current coupling output terminal 122B of the coupling capacitor C and the direct current coupling output terminal 121C through the first resistor R1.

[0053] Specifically, the gate of the second switch tube Q2 is connected with the output terminal (i.e., the first control output terminal 113) of the first inverter inv1, the source of the second switch tube Q2 is grounded, and the drain of the second switch tube Q2 is connected between the alternating current coupling output terminal 122B of the coupling capacitor C and the direct current coupling output terminal 121C through the second resistor R2.

[0054] According to some embodiments of the present application, the first switch tube Q1 and the second switch tube Q2 are both N-channel metal oxide semiconductor field effect tubes.

[0055] Further, the functions implemented by the voltage dividing unit, the first switch tube Q1, and the second switch tube Q2 are further described.

[0056] Specifically, the first switch tube Q1 is configured to receive the second logic control signal vinn output by the logic gate and2, and when the second logic control signal vinn is at a high level, the first switch tube Q1 is turned on; and when the second logic control signal vinn is at a low level, the first switch tube Q1 is turned off.

[0057] Specifically, the second switch tube Q2 is configured to receive the first logic control signal vinp output by the first inverter inv1, and when the first logic control signal vinp is at a high level, the second switch tube Q2 is turned on; and when the first logic control signal vinp is at a low level, the second switch tube Q2 is turned off.

[0058] Specifically, the voltage dividing unit comprises: a first resistor R1, a second resistor R2 and a third resistor R3; wherein, the access state of the first resistor R1 is related to the on-off state of the first switch tube Q1, and the access state of the second resistor R2 is related to the on-off state of the second switch tube Q2. Specifically, when the first switch tube Q1 is turned on and the second switch tube Q2 is turned off, the branch in which the first resistor R1 is located is turned on, the branch in which the second resistor R2 is located is turned off, and voltage dividing is performed by the first resistor R1 and the third resistor R3; when the first switch tube Q1 is turned off and the second switch tube Q2 is turned on, the branch in which the first resistor R1 is located is turned off, the branch in which the second resistor R2 is located is turned on, and voltage dividing is performed by the second resistor R2 and the third resistor R3.

[0059] According to some embodiments of the present application, the inverting output module 130 comprises: a second inverter inv2 and a third inverter inv3. Further, the specific connection relationship between the second inverter inv2 and the third inverter inv3 is further described.

[0060] Specifically, the input end of the second inverter inv2 serves as an inverting input end 131, and the inverting input end 131 is connected with the direct current coupling output end 121C; the input end of the third inverter inv3 is connected with the output end of the second inverter inv2, and the output end of the third inverter inv3 serves as an inverting output end 132, and the inverting output end 132 is used for outputting a target level shift signal Vout.

[0061] Further, the functions realized by the second inverter inv2 and the third inverter inv3 are further described.

[0062] Specifically, the logic expression of the second inverter inv2 and the third inverter inv3 is: The logic operation performed by the second inverter inv2 and the third inverter inv3 is: taking the inverse of the input A to obtain the output Y.

[0063] Specifically, in the embodiments of the present application, when the coupling signal input into the second inverter inv2 is greater than the threshold voltage Vth (Vth=VCC / 2), it is equivalent to inputting a high level into the second inverter inv2, the second inverter inv2 takes the inverse of the high level, and outputs a low level; when the coupling signal input into the second inverter inv2 is less than the threshold voltage Vth (Vth=VCC / 2), it is equivalent to inputting a low level into the second inverter inv2, the second inverter inv2 takes the inverse of the low level, and outputs a high level.

[0064] Specifically, in this embodiment, when the second inverter inv2 outputs a high level to the third inverter inv3, the high point of the third inverter inv3 is inverted, and a low-level target level transfer signal Vout is output; when the second inverter inv2 outputs a low level to the third inverter inv3, the low level of the third inverter inv3 is inverted, and a high-level target level transfer signal Vout is output.

[0065] According to the level shifting circuit 100 provided in the first aspect embodiment of this application, through the cooperation of the logic control module 110, the AC / DC coupling module 120 and the inverting output module 130, the control method of the level shifting circuit 100 provided in the embodiment of this application is executed to realize the level shifting function of both input AC signals and DC signals, so that the level shifting circuit 100 realizes the level shifting function of both input AC signals and DC signals through AC coupling and DC coupling.

[0066] It is important to emphasize that currently common high-speed level conversion circuits are basically based on, for example... Figure 1 The circuit architecture of the level shifting circuit shown has been improved, for example, by using a series PMOS or NMOS transistor, using a low-voltage NMOS transistor, or adding a bias voltage. Although the level shifting speed has been improved to some extent, it is still not fast enough, and problems such as long delay and duty cycle misalignment remain unresolved. There are also... Figure 2 The circuit shown uses AC coupling to achieve level shifting, which effectively achieves high speed, low delay, and good duty cycle. Figure 2 The capacitive reactance of the capacitor is Xc = 1 / (2πfC); the higher the frequency of the AC signal, the smaller the capacitive reactance; the lower the frequency of the AC signal, the larger the capacitive reactance. Therefore, this technology can only support the conversion of high-speed signals, that is, it can only support the conversion of high-speed signals with a signal period less than the time constant RC. For low-speed or DC levels, this structure is powerless. This application realizes an ultra-high-speed level shifting circuit 100 that combines AC coupling and DC coupling, which solves the problems of long delay, low speed, and duty cycle misalignment existing in current level shifting circuits, and can realize level shifting functions for high-frequency AC signals, low-frequency AC signals, and DC signals based on this level shifting circuit.

[0067] Those skilled in the art will understand that the circuit structure shown in the figures does not constitute a limitation on the embodiments of the present invention, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0068] Those skilled in the art can understand that the circuit structure and application scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, with the evolution of circuit structure and the appearance of new application scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0069] Based on the above system structure, the following proposes various embodiments of the control method of the level shift circuit 100 of the present application.

[0070] The second aspect, as Figure 5 indicated, the control method of the level shift circuit can be applied to the level shift circuit as Figure 3 indicated, the level shift circuit includes: a logic control module, an AC-DC coupling module, and an inverting output module; the AC-DC coupling module includes: a DC coupling unit and an AC coupling unit; the control method of the level shift circuit can include but is not limited to steps S110 to S120.

[0071] Step S110: When the enable signal is high, the logic control module performs logical judgment processing according to the enable signal and the input signal, outputs the first logic control signal and the second logic control signal to the AC-DC coupling module, determines the on-off state of the branch where the AC coupling unit is located, controls the DC coupling unit to perform routing voltage division processing, and outputs the coupling signal to the inverting output module; wherein the input signal is a DC signal or an AC signal.

[0072] Step S120: The inverting output module inverts the coupling signal, and outputs the target level shift signal.

[0073] Through steps S110 to S120, during the operation of the level shift circuit, when the enable signal is high, the logic control module performs logical judgment processing according to the enable signal and the input signal, outputs the first logic control signal and the second logic control signal to the AC-DC coupling module, determines the on-off state of the branch where the AC coupling unit is located, controls the DC coupling unit to perform routing voltage division processing, and outputs the coupling signal to the inverting output module; wherein the input signal is a DC signal or an AC signal; then, the inverting output module inverts the coupling signal, and outputs the target level shift signal; in this way, the level shift function of low delay, high speed, and good duty cycle can be realized for both the input DC signal and the AC signal. That is to say, the embodiments of the present application can realize the level shift function of low delay, high speed, and good duty cycle for both AC signals and DC signals by combining the AC coupling unit and the DC coupling unit.

[0074] According to some embodiments of the present application, step S110 is further illustrated, wherein the logic control module performs logic judgment processing according to the enable signal and the input signal, outputs the first logic control signal and the second logic control signal to the AC-DC coupling module, determines the on-off state of the branch in which the AC coupling unit is located, controls the DC coupling unit to perform routing voltage division processing, and outputs the coupling signal to the inverting output module, including but not limited to steps S111 and S112.

[0075] Step S111: When the input signal is a DC signal, the logic control module performs first logic operation according to the high-level enable signal and the DC signal, outputs the first logic control signal and the second logic control signal to the AC-DC coupling module, makes the branch in which the AC coupling unit is located open, and controls the DC coupling unit to perform first voltage division processing to output the coupling signal to the inverting output module.

[0076] Step S112: When the input signal is an AC signal, the logic control module performs second logic operation according to the high-level enable signal and the AC signal, outputs the first logic control signal and the second logic control signal to the AC-DC coupling module, makes the branch in which the AC coupling unit is located conductive, controls the AC coupling unit and the DC coupling unit to perform second voltage division processing, and outputs the coupling signal to the inverting output module.

[0077] Specifically, the input DC signal can be high level or low level. The input AC signal can be a high-frequency AC signal or a low-frequency AC signal.

[0078] Specifically, the input AC signal includes:

[0079] The present application realizes the level shift function of the input DC signal through step S111, and realizes the level shift function of the input AC signal through step S112.

[0080] Taking an example, combining Figure 4 The circuit working principle of realizing the level shift function of the DC signal through step S111 is further illustrated.

[0081] Example one: when the enable signal en is high, the input signal Vin is a direct current signal, and the direct current signal is low, the logic control module 110 performs a first logic operation according to the high enable signal en and the direct current signal, including: first, the nand logic gate nand2 performs a logic operation on the high enable signal en and the low direct current signal, and outputs a high level to the first inverter inv1 and the and logic gate and2; then, the first inverter inv1 inverts the high level and outputs the first logic control signal vinp as low; at the same time, the and logic gate and2 performs a logic operation on the high enable signal en and the high level output by the and logic gate and2, and outputs the second logic control signal vinn as high. The first logic control signal vinp and the second logic control signal vinn are output to the AC-DC coupling module 120. Since the input signal Vin is a direct current signal, and the AC coupling unit 122 has the property of passing AC and blocking DC, the branch in which the AC coupling unit 122 is located is open; the low first logic control signal vinp controls the second switch tube Q2 to be open, so that the branch in which the second resistor R2 is located is open; the high second logic control signal vinn controls the first switch tube Q1 to be conductive, so that the branch in which the first resistor R1 is located is conductive; the first resistor R1 and the third resistor R3 perform voltage division processing. At this time, the voltage value of the coupling signal vop is R1 / (R1+R3), and by reasonably setting the resistance values of the first resistor R1 and the third resistor R3, R1 / (R1+R3)=(VCC-VDD) / 2, that is, vop=(VCC-VDD) / 2. The coupling signal vop is output to the inverting output module 130. Since vop=(VCC-VDD) / 2 is less than the threshold voltage Vth of the second inverter inv2 (Vth=VCC / 2), it is equivalent to inputting a low level to the second inverter inv2. The second inverter inv2 inverts the low level and outputs a high level to the third inverter inv3. The third inverter inv3 inverts the high level again and outputs a low level. That is, the target level transfer signal Vout output by the third inverter inv3 is low.

[0082] Example two: when the enable signal en is high, the input signal Vin is a direct current signal, and the direct current signal is high, the logic control module 110 performs a first logic operation according to the high enable signal en and the direct current signal, including: first, the nand logic gate nand2 performs a logic operation on the high enable signal en and the high direct current signal to obtain a low level, and outputs the low level to the first inverter inv1 and the and logic gate and2 respectively; then, the first inverter inv1 performs an inversion operation on the low level to output the first logic control signal vinp as high; at the same time, the and logic gate and2 performs a logic operation on the high enable signal en and the low level output by the and logic gate and2 to output the second logic control signal vinn as low. The first logic control signal vinp and the second logic control signal vinn are output to the AC-DC coupling module 120, and since the input signal Vin is a direct current signal and the AC coupling unit 122 has the property of passing AC while blocking DC, the branch in which the AC coupling unit 122 is located is open; the high first logic control signal vinp controls the second switch tube Q2 to be turned on, so that the branch in which the second resistor R2 is located is turned on; the low second logic control signal vinn controls the first switch tube Q1 to be turned off, so that the branch in which the first resistor R1 is located is turned off, and the voltage is processed by the second resistor R2 and the third resistor R3. At this time, the voltage value of the coupling signal vop is R2 / (R2+R3), and by reasonably setting the resistance values of the second resistor R2 and the third resistor R3, R2 / (R2+R3)=(VCC+VDD) / 2, that is, vop=(VCC+VDD) / 2. The coupling signal vop is output to the inverting output module 130, and since vop=(VCC+VDD) / 2 is greater than the threshold voltage Vth of the second inverter inv2 (Vth=VCC / 2), it is equivalent to inputting a high level to the second inverter inv2. The second inverter inv2 inverts the high level, outputs a low level to the third inverter inv3, and the third inverter inv3 inverts the low level again, outputs a high level, that is, the target level shift signal Vout output by the third inverter inv3 is high.

[0083] Through example one and example two of step S111, the embodiment of the present application realizes the level shift function of the direct current signal by the direct current coupling path composed of the first resistor R1, the second resistor R2, the third resistor R3, the first switch tube Q1 and the second switch tube Q2.

[0084] Taking an example, combining Figure 4 Further illustrate the circuit working principle of realizing the level shift function of the alternating current signal through step S112.

[0085] Example three: when the enable signal en is high, the input signal Vin is an alternating current signal, and the alternating current signal jumps from low to high, the logic control module 110 performs the first logic operation according to the high enable signal en and the direct current signal, including: first, the NAND logic gate nand2 performs the logic operation on the high enable signal en and the high direct current signal to obtain a low level, and outputs the low level to the first inverter inv1 and the AND logic gate and2; then, the first inverter inv1 performs an inversion operation on the low level to output the first logic control signal vinp as high, that is, the first logic control signal vinp also jumps from low to high with the alternating current signal; due to the alternating coupling effect of the coupling capacitor C, according to the principle that the voltage across the capacitor cannot change abruptly, the voltage of the coupling signal vop will jump and increase by VDD, that is, the coupling signal vop jumps from (VCC-VDD) / 2 to (VCC+VDD) / 2; the coupling signal vop is output to the inverting output module 130, and since vop=(VCC+VDD) / 2 is greater than the threshold voltage Vth of the second inverter inv2 (Vth=VCC / 2), it is equivalent to inputting a high level to the second inverter inv2, and outputting a high level after inversion by the second inverter inv2 and the third inverter inv3, that is, the target level shift signal Vout output by the third inverter inv3 is high. At the same time, the AND logic gate and2 processes the high enable signal en and the low level output by the NAND logic gate nand2, and outputs the second logic control signal vinn as low, so that the high first logic control signal vinp controls the second switch Q2 to be turned on, and the low second logic control signal vinn controls the first switch Q1 to be turned off, and the second resistor R2 and the third resistor R3 are used for voltage division processing. After voltage division by the second resistor R2 and the third resistor R3, the coupling signal vop=(VCC+VDD) / 2, at this time, the direct current coupling path makes the voltage of the coupling signal vop stably maintain at (VCC+VDD) / 2, effectively solving the problem of gradual charge leakage due to the time constant τ (τ=RC) in the traditional alternating current coupling structure, and finally unable to realize the level shift function of the low-speed signal.

[0086] Example four: when the enable signal en is high, the input signal Vin is an alternating current signal, and the alternating current signal jumps from high to low, the logic control module 110 performs the first logic operation according to the high enable signal en and the direct current signal, including: first, the NAND logic gate nand2 performs the logic operation on the high enable signal en and the low direct current signal to obtain a high level, and outputs the high level to the first inverter inv1 and the AND logic gate and2; then, the first inverter inv1 performs an inversion operation on the high level to output the first logic control signal vinp as low; that is, the first logic control signal vinp also jumps from high to low with the alternating current signal; due to the alternating coupling effect of the coupling capacitor C, according to the principle that the voltage across the capacitor cannot change abruptly, the voltage of the coupling signal vop will jump down to VDD instantaneously, that is, the coupling signal vop jumps from (VCC+VDD) / 2 to (VCC-VDD) / 2, and the coupling signal vop is output to the inverting output module 130; since vop=(VCC-VDD) / 2 is less than the threshold voltage Vth of the second inverter inv2 (Vth=VCC / 2), it is equivalent to inputting a low level to the second inverter inv2, and outputting a low level after inversion by the second inverter inv2 and the third inverter inv3, that is, the target level shift signal Vout output by the third inverter inv3 is low. At the same time, the AND logic gate and2 processes the high enable signal en and the high level output by the NAND logic gate nand2, and outputs the second logic control signal vinn as high, so that the low first logic control signal vinp controls the second switch Q2 to be turned off, and the high second logic control signal vinn controls the first switch Q1 to be turned on, and the voltage is processed by the first resistor R1 and the third resistor R3. After the voltage is processed by the first resistor R1 and the third resistor R3, the coupling signal vop=(VCC-VDD) / 2, at this time, the direct current coupling path makes the voltage of the coupling signal vop stably maintain at (VCC-VDD) / 2, effectively solving the problem of gradual charge leakage due to the time constant τ (τ=RC) in the traditional alternating current coupling structure, and finally unable to realize the level shift function of the low-speed signal.

[0087] The application embodiment realizes the level shift function of the alternating current signal through example three and example four of step S112.

[0088] According to some embodiments of the present application, the control method of the level shift circuit 100 further comprises: step S130, when the enable signal en is low, the logic control module 110 performs a third logic judgment process according to the low enable signal en, and outputs the first logic control signal vinp and the second logic control signal vinn, both of which are low, to the AC-DC coupling module 120, so that the coupling signal output by the AC-DC coupling module 120 is equal to the voltage value output by the second power supply VCC, and the inverting output module 130 performs inverting processing on the coupling signal and outputs a high-level signal.

[0089] For example, in combination with Figure 4 The specific process of step S130 is described.

[0090] For example, when the enable signal en is low, the first logic control signal vinp and the second logic control signal vinn are both low, the first switch tube Q1 is turned off, the coupling signal vop is pulled up to VCC by the third resistor R3, the output end Vout of the third inverter inv3 outputs a high level, that is, the output target level shift signal Vout is high, and the entire level shift circuit 100 has no static current consumption.

[0091] In summary, the control method of the level shift circuit 100 according to the embodiments of the present application effectively realizes the level shift function of the full-band signal of the low-frequency signal, the high-frequency signal and the DC signal through AC coupling and DC coupling. Moreover, since the coupling signal vop instantaneously jumps when the input signal Vin jumps, the low delay, high speed and good duty cycle level shift effect can be achieved.

[0092] In a third aspect, the present application provides an electronic device comprising the level shift circuit according to any one of the embodiments of the first aspect.

[0093] The electronic device provided by the embodiments of the present application comprises the level shift circuit provided by the embodiments of the present application, which comprises a logic control module, an AC-DC coupling module and an inverting output module. During the operation of the level shift circuit, the control method of the level shift circuit provided by the embodiments of the present application can realize the low delay, high speed and good duty cycle level shift function of the input DC signal and AC signal. That is, the electronic device provided by the embodiments of the present application can realize the low delay, high speed and good duty cycle level shift function of the AC signal and DC signal by combining the AC coupling unit and the DC coupling unit.

[0094] It can be seen that the level shift circuit based on AC coupling and DC coupling has low delay, high speed and good duty cycle, and can realize low frequency signal and DC signal level shift function through DC coupling. Through the combination of AC coupling and DC coupling, the level shift function can be realized for low frequency signal, high frequency signal and DC signal, and has the effects of low delay, high speed and good duty cycle.

[0095] It should be noted that the electronic device of the embodiment can realize the control method of the level shift circuit of any of the foregoing embodiments, and therefore has the same technical principles and effects as the control method of the level shift circuit of any of the foregoing embodiments. To avoid redundant content, the details are not repeated here.

[0096] The above is a specific description of the preferred embodiment of the present application, but the present application is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the present application.

Claims

1. A level shifting circuit, characterized in that, include: The logic control module includes a first signal input terminal, a second signal input terminal, a first control output terminal, a second control output terminal, and a first power input terminal; The first signal input terminal is connected to the input signal source, the second signal input terminal is connected to the enable signal source, and the first power input terminal is connected to the first power source; An AC / DC coupling module includes a DC coupling unit and an AC coupling unit. The DC coupling unit includes a first control input terminal, a second control input terminal, a DC coupling output terminal, and a second power input terminal. The first control input terminal is connected to the first control output terminal, the second control input terminal is connected to the second control output terminal, and the second power input terminal is connected to a second power source. The AC coupling unit includes an AC coupling input terminal and an AC coupling output terminal. The AC coupling input terminal is connected to the first control output terminal, and the AC coupling output terminal is connected to the DC coupling output terminal. An inverting output module includes an inverting input terminal, an inverting output terminal, and a third power input terminal; the inverting input terminal is connected to the DC-coupled output terminal, the inverting output terminal is used to output a target level transfer signal, and the third power input terminal is connected to a second power supply. The logic control module includes: A NAND gate, wherein the first input terminal of the NAND gate is connected to an input signal source, and the second input terminal of the NAND gate is connected to an enable signal source; wherein the input signal source is used to generate an input signal; and the enable signal source is used to generate an enable signal. A first inverter, the input of which is connected to the output of the NAND gate; the output of the first inverter is the first control output, which is connected to the AC coupling input. The AND gate has its first input connected to the output of the NAND gate; its second input connected to the enable signal source; and its output is the second control output, which is connected to the second control input of the DC coupling unit. The inverting output module includes: a second inverter, the input terminal of which serves as the inverting input terminal and is connected to the DC-coupled output terminal; and a third inverter, the input terminal of which is connected to the output terminal of the second inverter and is used as the inverting output terminal, which is used to output a target level transfer signal.

2. The level transfer circuit according to claim 1, characterized in that, The AC coupling unit includes: A coupling capacitor, one end of which is the AC coupling input terminal and the other end of which is the AC coupling output terminal; the AC coupling input terminal is connected to the first control output terminal of the first inverter; the AC coupling output terminal is connected to the DC coupling output terminal of the DC coupling unit.

3. The level transfer circuit according to claim 2, characterized in that, The DC coupling unit includes: The voltage divider unit includes: a first resistor, a second resistor, and a third resistor; one end of the third resistor serves as a second power supply terminal and is connected to the second power supply, and the other end of the third resistor serves as the DC-coupled output terminal and is connected to the inverting input terminal. The first switching transistor has its gate connected to the second control output terminal of the AND logic gate, its source grounded, and its drain connected between the AC coupling output terminal and the DC coupling output terminal of the coupling capacitor via the first resistor. The second switching transistor has its gate connected to the first control output terminal of the first inverter, its source grounded, and its drain connected between the AC coupling output terminal and the DC coupling output terminal of the coupling capacitor via the second resistor.

4. The level shifting circuit according to claim 3, characterized in that, Both the first and second switching transistors are N-channel metal-oxide-semiconductor field-effect transistors.

5. A control method for a level transfer circuit, characterized in that, Applied to the level shifting circuit as described in claim 1, the level shifting circuit includes: a logic control module, an AC / DC coupling module, and an inverting output module; the AC / DC coupling module includes: a DC coupling unit and an AC coupling unit; The method includes: When the enable signal is high, the logic control module performs logical judgment processing based on the enable signal and the input signal, and outputs the first logic control signal and the second logic control signal to the AC / DC coupling module to determine the on / off state of the branch where the AC coupling unit is located, control the DC coupling unit to perform path selection and voltage division processing, and output the coupling signal to the inverting output module; wherein, the input signal is a DC signal or an AC signal; The inverting output module inverts the coupled signal and outputs the target level transfer signal.

6. The control method for the level transfer circuit according to claim 5, characterized in that, The logic control module performs logical judgment processing based on the enable signal and the input signal, outputs a first logic control signal and a second logic control signal to the AC / DC coupling module, determines the on / off state of the branch where the AC coupling unit is located, controls the DC coupling unit to perform path selection and voltage division processing, and outputs a coupling signal to the inverting output module, including: When the input signal is a DC signal, the logic control module performs a first logic operation based on the high-level enable signal and the DC signal, and outputs a first logic control signal and a second logic control signal to the AC / DC coupling module, causing the branch where the AC coupling unit is located to be disconnected, and controlling the DC coupling unit to perform a first voltage division process to output the coupling signal to the inverting output module; When the input signal is an AC signal, the logic control module performs a second logic operation based on the high-level enable signal and the AC signal, and outputs the first logic control signal and the second logic control signal to the AC / DC coupling module, so that the branch where the AC coupling unit is located is turned on, and controls the AC coupling unit and the DC coupling unit to perform a second voltage division process, and outputs the coupling signal to the inverting output module.

7. The control method for the level transfer circuit according to claim 5, characterized in that, The method further includes: When the enable signal is low, the logic control module performs a third logic judgment based on the low-level enable signal, and outputs a first logic control signal and a second logic control signal, both of which are low, to the AC / DC coupling module, so that the coupling signal output by the AC / DC coupling module is equal to the voltage value output by the second power supply. The inverting output module inverts the coupling signal and outputs a high-level signal.

8. An electronic device, characterized in that, Includes the level shifting circuit as described in any one of claims 1 to 4.

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