IO port level conversion circuit and electronic equipment

Abstract

The invention discloses an IO port level conversion circuit and electronic equipment. The conversion circuit comprises an input port, an output port and a switching circuit, the input port is used for inputting a received first level signal into the switching circuit; the output port is provided with a pull-down resistor and outputs a second level signal based on the control of the switching circuit; the switching circuit comprises a first switching tube, a second switching tube and a conversion power supply; the first switch tube comprises a first control end, a first injection end and a first collection end; the second switch tube comprises a second control end, a second injection end and a second collection end; the first collection end and the second collection end are connected with the conversion power supply; the first control end is connected with the input port, and the first injection end is grounded; the second control end is connected with the first collection end, and the second injection end is connected with the output port. According to the conversion circuit, stable level conversion can still be realized under the condition that the output end is provided with an internal pull-down resistor, and the cost increase caused by multi-channel integration is also avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of level signal processing circuits, and in particular to an IO port level conversion circuit and electronic equipment. Background Art

[0002] In modern electronic circuit design, IO port level conversion is the key link to achieve the conversion between different level signals. Currently, the common level conversion schemes mainly include the following two: 1. Use integrated IC chips for level conversion. This type of chip can usually integrate multiple signal conversions, such as two-way and four-way, and has the advantages of small size and high integration, which is suitable for multi-channel application scenarios. However, when only single-way level conversion is required, the cost of using integrated IC chips is relatively high and does not have an economic advantage.

[0003] 2. Common single MOS tube circuit design is also a commonly used level conversion method. This type of design has a simple structure and low cost, and is suitable for single-channel or small-scale level conversion needs. However, when the single MOS tube circuit has an internal pull-down resistor at the output end, it cannot effectively achieve stable level conversion, which limits its application range.

[0004] In some specific circuit designs, such as the scan head reset and enable signal lines of some manufacturers, pull-down resistors are usually integrated internally. When performing level conversion on such signal lines, the traditional integrated IC chip solution is difficult to meet the economic requirements due to its high cost; and the single MOS tube circuit design cannot process the output end with a pull-down resistor and cannot achieve reliable level conversion. Therefore, the existing level conversion solution has certain limitations in specific application scenarios. Summary of the invention

[0005] The purpose of the present invention is to solve the above technical problems and provide a cost-effective and effectively process IO port level conversion circuit and electronic equipment with a pull-down resistor output end.

[0006] In order to achieve the above object, the present invention provides an IO port level conversion circuit, characterized in that it includes an input port, an output port and a switch circuit arranged between the input port and the output port; the input port is used to input a received first level signal into the switch circuit; the output port is provided with a pull-down resistor, and outputs a second level signal based on the control of the switch circuit; The switch circuit includes a first switch tube, a second switch tube and a conversion power supply; The first switch tube includes a first control end and a first injection end and a first collection end connected or disconnected based on the first control end; the second switch tube includes a second control end and a second injection end and a second collection end connected or disconnected based on the second control end; The first collecting end and the second collecting end are connected to the conversion power supply; The first control terminal is connected to the input port, and the first injection terminal is grounded; The second control end is connected to the first collecting end, and the second injection end is connected to the output port; The first switch tube is used to control the working state of the second switch tube.

[0007] Preferably, when the first level signal received by the input port is at a high level, the first switch tube is turned on and the second switch tube is turned on; when the first level signal received by the input port is at a low level, the first switch tube is turned off and the second switch tube is turned off.

[0008] Preferably, the first switch tube is an NMOS tube, and the second switch tube is a PMOS tube.

[0009] Preferably, the first injection terminal is also connected to the first control terminal via a first resistor; the second control terminal and the first collection terminal are connected to the second collection terminal via a second resistor.

[0010] Preferably, the input port is further provided with a first filtering circuit connected in parallel with the first control terminal, and the second injection terminal is further provided with a second filtering circuit connected in parallel with the output port.

[0011] The present invention also provides an electronic device, comprising a control circuit, an execution circuit, and an IO port level conversion circuit arranged between the control circuit and the execution circuit; The IO port level conversion circuit includes an input port, an output port, and a switch circuit arranged between the input port and the output port; The input port is connected to the control circuit to receive a first level signal from the control circuit; The output port is connected to the execution circuit, the execution circuit works based on the second level signal output by the output port, and the output port is also provided with a pull-down resistor; The switch circuit includes a first switch tube, a second switch tube and a conversion power supply; The first switch tube includes a first control end and a first injection end and a first collection end connected or disconnected based on the first control end; the second switch tube includes a second control end and a second injection end and a second collection end connected or disconnected based on the second control end; The first collecting end and the second collecting end are connected to the conversion power supply; The first control terminal is connected to the input port, and the first injection terminal is grounded; The second control end is connected to the first collecting end, and the second injection end is connected to the output port; The first switch tube is used to control the working state of the second switch tube.

[0012] Preferably, when the first level signal received by the input port is at a high level, the first switch tube is turned on and the second switch tube is turned on; when the first level signal received by the input port is at a low level, the first switch tube is turned off and the second switch tube is turned off.

[0013] Preferably, the first switch tube is an NMOS tube, and the second switch tube is a PMOS tube.

[0014] Preferably, the first injection terminal is also connected to the first control terminal via a first resistor; the second control terminal and the first collection terminal are connected to the second collection terminal via a second resistor.

[0015] Preferably, the input port is further provided with a first filtering circuit connected in parallel with the first control terminal, and the second injection terminal is further provided with a second filtering circuit connected in parallel with the output port.

[0016] Compared with the prior art, the IO port level conversion circuit provided by the above technical solution of the present invention controls the on-off state of the second switch tube through the first switch tube, so that the output port outputs the second level signal based on the first level signal, so that the circuit can still achieve stable level conversion when the output end has an internal pull-down resistor. This solution avoids the problem of the pull-down resistor affecting the circuit driving ability through cascade control, and enhances the stability of the output signal. In addition, compared with the integrated IO conversion IC, this solution adopts discrete component design, which can meet the single-channel level conversion requirements and avoid the cost increase caused by multi-channel integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the working principle of the electronic device in the embodiment of the present invention.

[0018] Figure 2 FIG. 4 is a circuit diagram of a conversion circuit in one embodiment of the present invention.

[0019] Figure 3 FIG. 4 is a circuit schematic diagram of a conversion circuit in another embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0021] This embodiment discloses an electronic device to solve the problem of level conversion when an output IO port has an internal pull-down resistor and save costs. Figure 1 The electronic device includes a control circuit C1, an execution circuit C3, and an IO port level conversion circuit C2 disposed between the control circuit C1 and the execution circuit C3. The control circuit C1 outputs a first level signal, and through the conversion circuit C2, outputs a second level signal to the execution circuit C3, so that the execution circuit C3 performs a corresponding action according to the instruction of the control circuit C1.

[0022] like Figure 2 The IO port level conversion circuit C2 includes an input port DIN, an output port DOUT, and a switch circuit arranged between the input port DIN and the output port DOUT.

[0023] The input port DIN is connected to the control circuit C1 to receive a first level signal from the control circuit C1.

[0024] The output port DOUT is connected to the execution circuit C3 , and the execution circuit C3 operates based on the second level signal output by the output port DOUT. The output port DOUT is further provided with a pull-down resistor R0 .

[0025] The switch circuit includes a first switch tube Q1, a second switch tube Q2 and a conversion power source VCC.

[0026] The first switch transistor Q1 includes a first control terminal G1 and a first injection terminal S1 and a first collection terminal D1 connected or disconnected based on the first control terminal G1. The second switch transistor Q2 includes a second control terminal G2 and a second injection terminal S2 and a second collection terminal D2 connected or disconnected based on the second control terminal G2.

[0027] The first collecting terminal D1 and the second collecting terminal D2 are connected to the conversion power source VCC.

[0028] The first control terminal G1 is connected to the input port DIN, and the first injection terminal S1 is grounded.

[0029] The second control terminal G2 is connected to the first collecting terminal D1 , and the second injection terminal S2 is connected to the output port DOUT.

[0030] The first switch tube Q1 is used to control the working state of the second switch tube Q2.

[0031] It is worth noting that the semiconductor switch tube includes three electrode ends, namely the control end, the injection end and the collection end. The control end is used to adjust the conduction state of the switch tube, the injection end is responsible for the injection of carriers, and the collection end is used for the collection of carriers and the output of current.

[0032] In this embodiment, when the control circuit C1 needs to start the execution circuit C3, it outputs a first level signal to the conversion circuit C2. The first level signal controls the on-off state of the second switch tube Q2 through the first switch tube Q1, so that the output port DOUT outputs a second level signal, and the execution circuit C3 starts working after receiving the second level signal. This IO port level conversion circuit C2 can still achieve stable level conversion when the output end has an internal pull-down resistor R0. The conversion circuit C2 avoids the problem of the pull-down resistor R0 affecting the circuit driving ability through cascade control, and enhances the stability of the output signal.

[0033] In addition, compared with the integrated IO conversion IC, this solution adopts discrete component design, which can meet the needs of single-channel level conversion and avoid the cost increase caused by multi-channel integration.

[0034] Furthermore, the cascade design of the first switch tube Q1 and the second switch tube Q2 has clear logic, and cooperates with the conversion power supply VCC to effectively isolate the level difference between the input signal and the output signal, avoiding interference problems that may be caused by direct coupling, and ensuring the reliability of the circuit.

[0035] On the other hand, when the first level signal received by the input port DIN is high, the first switch tube Q1 is turned on and the second switch tube Q2 is turned on. When the first level signal received by the input port DIN is low, the first switch tube Q1 is turned off and the second switch tube Q2 is turned off.

[0036] Specifically, taking the first level signal of 1.8V and the conversion power supply VCC of 3.3V as an example, when the second switch tube Q2 is turned on, the second level signal output by the second injection terminal S2 to the output port DOUT is 3.3V.

[0037] On the other hand, the first switch tube Q1 is an NMOS tube, and the second switch tube Q2 is a PMOS tube.

[0038] Then, for the first switch tube Q1 and the second switch tube Q2, the first control terminal G1 and the second control terminal G2 are gates, the first injection terminal S1 and the second injection terminal S2 are sources, and the first collection terminal D1 and the second collection terminal D2 are drains.

[0039] Since the MOS transistor is a voltage-driven switch transistor, the first injection terminal S1 is also connected to the first control terminal G1 through the first resistor R1. The second control terminal G2 and the first collector terminal D1 are connected to the second collector terminal D2 through the second resistor R2. In addition, the input port DIN is also connected to the first control terminal D1 through the third resistor R3.

[0040] When the first level signal received by the input port DIN is at a high level, the first deflection voltage is applied to the first control terminal G1 and the first injection terminal S1 of the first switch tube Q1 through the first resistor R1, and the first switch tube Q1 is turned on under the driving of the first deflection voltage. After the first switch tube Q1 is turned on, the conversion power supply VCC is applied to the second deflection voltage between the second control terminal G2 and the second collection terminal D2 of the second switch tube Q2 through the second resistor R2, and the second switch tube Q2 is turned on under the action of the second deflection voltage, so that the second level signal output by the output port DOUT is equal to the level state of the conversion voltage.

[0041] On the other hand, Figure 3 The input port DIN is further provided with a first filter circuit L1 connected in parallel with the first control terminal G1, and the second injection terminal S2 is further provided with a second filter circuit L2 connected in parallel with the output port DOUT.

[0042] The first filter circuit L1 can filter out interference signals in the input first level signal, and the second filter circuit L2 can filter out clutter signals in the output second level signal, thereby ensuring the stability of the conversion circuit C2.

[0043] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. An IO port level conversion circuit, characterized in that: comprising an input port, an output port and a switch circuit arranged between the input port and the output port; The input port is used to input the received first level signal into the switch circuit; The output port is provided with a pull-down resistor, and outputs a second level signal based on the control of the switch circuit; The switch circuit includes a first switch tube, a second switch tube and a conversion power supply; The first switch tube includes a first control end and a first injection end and a first collection end connected or disconnected based on the first control end; the second switch tube includes a second control end and a second injection end and a second collection end connected or disconnected based on the second control end; The first collecting end and the second collecting end are connected to the conversion power supply; The first control terminal is connected to the input port, and the first injection terminal is grounded; The second control end is connected to the first collecting end, and the second injection end is connected to the output port; The first switch tube is used to control the working state of the second switch tube.

2. The IO port level conversion circuit according to claim 1, characterized in that: When the first level signal received by the input port is at a high level, the first switch tube is turned on and the second switch tube is turned on; when the first level signal received by the input port is at a low level, the first switch tube is turned off and the second switch tube is turned off.

3. The IO port level conversion circuit according to claim 1, characterized in that: The first switch tube is an NMOS tube, and the second switch tube is a PMOS tube.

4. The IO port level conversion circuit according to claim 3, characterized in that: The first injection terminal is also connected to the first control terminal through a first resistor; the second control terminal and the first collection terminal are connected to the second collection terminal through a second resistor.

5. The IO port level conversion circuit according to claim 1, characterized in that: The input port is further provided with a first filter circuit connected in parallel with the first control terminal, and the second injection terminal is further provided with a second filter circuit connected in parallel with the output port.

6. An electronic device, characterized in that: It includes a control circuit, an execution circuit, and an IO port level conversion circuit arranged between the control circuit and the execution circuit; The IO port level conversion circuit includes an input port, an output port, and a switch circuit arranged between the input port and the output port; The input port is connected to the control circuit to receive a first level signal from the control circuit; The output port is connected to the execution circuit, the execution circuit works based on the second level signal output by the output port, and the output port is also provided with a pull-down resistor; The switch circuit includes a first switch tube, a second switch tube and a conversion power supply; The first switch tube includes a first control end and a first injection end and a first collection end connected or disconnected based on the first control end; the second switch tube includes a second control end and a second injection end and a second collection end connected or disconnected based on the second control end; The first collecting end and the second collecting end are connected to the conversion power supply; The first control terminal is connected to the input port, and the first injection terminal is grounded; The second control end is connected to the first collecting end, and the second injection end is connected to the output port; The first switch tube is used to control the working state of the second switch tube.

7. The electronic device according to claim 6, characterized in that: When the first level signal received by the input port is at a high level, the first switch tube is turned on and the second switch tube is turned on; when the first level signal received by the input port is at a low level, the first switch tube is turned off and the second switch tube is turned off.

8. The electronic device according to claim 6, characterized in that: The first switch tube is an NMOS tube, and the second switch tube is a PMOS tube.

9. The electronic device according to claim 8, characterized in that: The first injection terminal is also connected to the first control terminal through a first resistor; the second control terminal and the first collection terminal are connected to the second collection terminal through a second resistor.

10. The electronic device according to claim 6, characterized in that: The input port is further provided with a first filter circuit connected in parallel with the first control terminal, and the second injection terminal is further provided with a second filter circuit connected in parallel with the output port.

Images