Control circuit for realizing communication between 3.3 V and 5V systems at low cost

Abstract

A control circuit for realizing communication between 3.3 V and 5V systems at low cost is characterized by comprising a main control chip, a voltage stabilizing circuit module, a serial communication voltage conversion module and a radar interface module, the main control chip is electrically connected with the serial communication voltage conversion module and the radar interface module respectively, a power supply input end of the voltage stabilizing circuit module is electrically connected with a power supply, and a power supply output end of the radar interface module is electrically connected with the power supply. The power output end of the voltage stabilizing circuit module is electrically connected with the main control chip and the serial communication voltage conversion module, and the serial communication voltage conversion module is electrically connected with the radar interface module. According to the control circuit, only several cheap electronic components are used, voltage conversion of communication of different voltage systems can be achieved by adjusting resistance parameters without a special voltage conversion integrated chip, the requirements of clients are met, meanwhile, the control circuit has the advantages of being simple, reliable and low in cost, and the control circuit is suitable for popularization and application. And moreover, the stability of the whole circuit is good, and different voltage conversion can be realized by adjusting hardware according to customer requirements.

Description

Technical Field

[0001] This utility model relates to the field of children's bed technology, and in particular to a low-cost control circuit for communication between 3.3V and 5V systems. Background Technology

[0002] The crib uses an external radar module to monitor the child's real-time status. Data is transmitted between the crib control board and the radar module via a serial communication circuit. The crib control board is powered by DC 5V, while the radar module's control power supply is DC 3.3V. Since these two systems have different voltage levels, voltage conversion must be addressed for data transmission. Currently, this is often solved by adding a 5V to 3.3V voltage regulator circuit to the crib control board, and then using a dedicated level conversion integrated chip or discrete electronic components to handle the level conversion for data communication between the different voltage systems. While this implementation can achieve the required functionality, it is not cost-effective and requires a larger circuit board due to its complexity.

[0003] Therefore, further improvements are necessary. Utility Model Content

[0004] The purpose of this invention is to provide a low-cost control circuit that enables communication between 3.3V and 5V systems, which is simple, stable, low-cost, and highly practical, in order to overcome the shortcomings of the prior art.

[0005] A low-cost control circuit for communication between 3.3V and 5V systems, designed for this purpose, is characterized by comprising a main control chip, a voltage regulator module, a serial communication voltage conversion module, and a radar interface module. The main control chip is electrically connected to both the serial communication voltage conversion module and the radar interface module. The power input terminal of the voltage regulator module is electrically connected to the power supply, and the power output terminal of the voltage regulator module is electrically connected to both the main control chip and the serial communication voltage conversion module. The serial communication voltage conversion module is electrically connected to the radar interface module.

[0006] The serial communication voltage conversion module includes a buck converter circuit and a boost converter circuit. The buck converter circuit is connected to the main control chip and the radar interface module, respectively, and the boost converter circuit is connected to the main control chip and the radar interface module, respectively.

[0007] The voltage regulator circuit module includes a voltage regulator chip and a resistor R1. One end of the resistor R1 is connected to the power supply, and the other end of the resistor R1 is connected to pin 2 of the voltage regulator chip. Pin 3 of the voltage regulator chip is connected to the +5V power supply output terminal, and pin 1 of the voltage regulator chip is connected to the negative terminal of the DC5V power supply.

[0008] The voltage regulator circuit module also includes electrolytic capacitor EC1, electrolytic capacitor EC2 and capacitor C1. One end of resistor R1 is connected to the positive terminal of electrolytic capacitor EC1, and the other end of resistor R1 is connected to one end of capacitor C1. Pin 3 of the voltage regulator chip is connected to the positive terminal of electrolytic capacitor EC2. The negative terminals of electrolytic capacitor EC1, the other end of capacitor C1 and the negative terminals of electrolytic capacitor EC2 are respectively connected to the negative terminal of DC5V power supply.

[0009] The radar interface module includes a terminal block radar interface and a PMOS transistor Q1. Pin 1 of the terminal block radar interface is connected to the radar module's communication receive pin LD_RX, pin 2 of the terminal block radar interface is connected to the radar module's communication transmit pin LD_TX, pin 3 of the terminal block radar interface is connected to the negative terminal of the DC 5V power supply, pin 4 of the terminal block radar interface is connected to the drain terminal of the PMOS transistor Q1, and the source terminal of the PMOS transistor Q1 is connected to the power supply.

[0010] The radar interface module also includes resistors R2 and R3 and an NPN transistor Q2. The source (S) of PMOS transistor Q1 is connected to one end of resistor R2, the gate (G) of PMOS transistor Q1 is connected to one end of resistor R3, the other end of resistor R3 is connected to the other end of resistor R2 and the collector of NPN transistor Q2, the emitter of NPN transistor Q2 is connected to the negative terminal of DC 5V power supply, and the base of NPN transistor Q2 is connected to pin 5 of the main control chip.

[0011] The main control chip is equipped with a filter circuit, which includes a capacitor C2. One end of the capacitor C2 is connected to the +5V power supply output terminal, and the other end of the capacitor C2 is connected to the negative terminal of the DC5V power supply.

[0012] Pin 9 of the main control chip is connected to the +5V power output terminal, and pin 7 of the main control chip is connected to the negative terminal of the DC5V power supply.

[0013] The step-down converter circuit includes resistors R4 and R5 and capacitor C3. One end of resistor R5 is connected to pin 1 of the main control chip, and the other end of resistor R5 is connected to one end of resistor R4, one end of capacitor C3 and pin 1 of the radar interface terminal. The other ends of resistor R4 and capacitor C3 are connected to the negative terminal of the DC5V power supply.

[0014] The boost converter circuit includes resistors R6, R7, and R8, NPN transistors Q3 and Q4. One end of resistor R6 is connected to pin 2 of the radar interface terminal block, and the other end of resistor R6 is connected to the base of NPN transistor Q3. The collector of NPN transistor Q3 is connected to the base of NPN transistor Q4 and one end of resistor R7. The emitters of NPN transistor Q3 and NPN transistor Q4 are connected to the negative terminal of the DC 5V power supply. The collector of NPN transistor Q4 is connected to one end of resistor R8 and pin 2 of the main control chip. The other ends of resistors R7 and R8 are connected to the +5V power supply output terminal.

[0015] The control circuit of this utility model uses only a few inexpensive electronic components. By adjusting the resistance parameters, it can achieve voltage conversion for communication between different voltage systems without the need for a dedicated voltage conversion integrated chip. While meeting customer requirements, it also has the advantages of simple, reliable, and low-cost circuit. Moreover, the stability of the entire circuit is also very good. Different voltage conversions can be achieved by adjusting the hardware according to customer needs. At the same time, this solution can make full use of existing mature components, improving the reliability of the system and the convenience of production. In addition, the control circuit of this solution can also be applied to other products with similar requirements. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the working principle of the control circuit in one embodiment of the present invention.

[0017] Figure 2 This is a circuit diagram of the main control chip in one embodiment of the present invention.

[0018] Figure 3 This is a circuit diagram of a voltage regulator circuit module in one embodiment of the present invention.

[0019] Figure 4 This is a circuit diagram of a serial communication voltage conversion module in one embodiment of the present invention.

[0020] Figure 5 This is a circuit diagram of the radar interface module in one embodiment of the present invention. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] See Figures 1-5This low-cost control circuit enables communication between 3.3V and 5V systems. It includes a main control chip 1, a 5V voltage regulator module 2, a serial communication voltage conversion module 3, and a radar interface module 4. The main control chip 1 is electrically connected to both the serial communication voltage conversion module 3 and the radar interface module 4. The power input of the voltage regulator module 2 is connected to a DC 12V power supply, and its output is connected to both the main control chip 1 and the serial communication voltage conversion module 3. The serial communication voltage conversion module 3 is then connected to the radar interface module 4. Control data sent from the main control chip 1 to the radar module is converted to a 3.3V signal by the serial communication voltage conversion module 3 and received by the radar module. Similarly, detection data sent from the radar module is converted to a 5V signal by the serial communication voltage conversion module 3 and received by the main control chip 1. Based on the needs of children's beds, this low-cost 3.3V to 5V level conversion circuit was designed. While meeting the low-cost requirement, it utilizes a simple circuit and adjusts hardware parameters to change the voltage level, thus achieving voltage conversion between 3.3V and 5V power supply systems for serial communication.

[0023] The serial communication voltage conversion module 3 includes a buck converter circuit 5 and a boost converter circuit 6. The buck converter circuit 5 is connected to the main control chip 1 and the radar interface module 4, respectively, and the boost converter circuit 6 is connected to the main control chip 1 and the radar interface module 4, respectively. The serial communication voltage conversion module 3 is a 3.3V to 5V level conversion circuit module.

[0024] The voltage regulator circuit module 2 includes a voltage regulator chip 7 and a resistor R1. One end of the resistor R1 is connected to the +12V power supply, and the other end of the resistor R1 is connected to pin 2 of the voltage regulator chip 7. Pin 3 of the voltage regulator chip 7 is connected to the +5V power supply output terminal (i.e., the positive terminal of the DC 5V power supply). Pin 3 of the voltage regulator chip 7 outputs the +5V power supply, and pin 1 of the voltage regulator chip 7 is connected to the negative terminal of the DC 5V power supply. The voltage regulator chip 7 is an LDO constant current voltage regulator chip.

[0025] The voltage regulator circuit module 2 also includes electrolytic capacitor EC1, electrolytic capacitor EC2 and capacitor C1. One end of resistor R1 is connected to the positive terminal of electrolytic capacitor EC1, and the other end of resistor R1 is connected to one end of capacitor C1. Pin 3 of voltage regulator chip 7 is connected to the positive terminal of electrolytic capacitor EC2. The negative terminal of electrolytic capacitor EC1, the other end of capacitor C1 and the negative terminal of electrolytic capacitor EC2 are respectively connected to the negative terminal of DC5V power supply.

[0026] The main control chip 1, voltage regulator circuit module 2, serial communication voltage conversion module 3, and radar interface module 4 are mounted on the control board.

[0027] The DC12V power supply is stepped down by resistor R1 and then outputs DC5V through an LDO constant current regulator chip to power the entire control board. Capacitors EC1, EC2, and C1 act as filters to increase the system's anti-interference performance.

[0028] The radar interface module 4 includes a terminal block radar interface 8 and a PMOS transistor Q1 (P-channel MOS transistor). Pin 1 of the terminal block radar interface 8 is connected to the communication receiving pin LD_RX of the radar module, pin 2 of the terminal block radar interface 8 is connected to the communication transmitting pin LD_TX of the radar module, pin 3 of the terminal block radar interface 8 is connected to the negative terminal of the DC5V power supply, pin 4 of the terminal block radar interface 8 is connected to the drain (D) terminal of the PMOS transistor Q1, and the source (S) terminal of the PMOS transistor Q1 is connected to the +12V power supply.

[0029] The radar interface module 4 also includes resistors R2 and R3 and an NPN transistor Q2. The source (S) of the PMOS transistor Q1 is connected to one end of resistor R2, the gate (G) of the PMOS transistor Q1 is connected to one end of resistor R3, the other end of resistor R3 is connected to the other end of resistor R2 and the collector of the NPN transistor Q2, the emitter of the NPN transistor Q2 is connected to the negative terminal of the DC 5V power supply, and the base of the NPN transistor Q2 is connected to pin 5 of the main control chip 1.

[0030] like Figure 5 As shown, pins 1 and 2 of the radar interface 8 are connected to the communication receive and transmit pins of the radar module, respectively, to realize data transmission between the radar module and the main control chip 1. Pins 3 and 4 of the radar interface 8 provide DC12V power to the radar module. When pin 5 of the main control chip 1 is low, NPN transistor Q2 is not turned on, and PMOS transistor Q1 is also in the cut-off state, so the radar module does not have DC12V power. When pin 5 of the main control chip 1 is high, NPN transistor Q2 is turned on, and PMOS transistor Q1 is also in the turned-on state, so the radar module has DC12V power and can work.

[0031] The main control chip 1 is equipped with a filter circuit 9, which includes a capacitor C2. One end of the capacitor C2 is connected to the +5V power supply output terminal, and the other end of the capacitor C2 is connected to the negative terminal of the DC5V power supply. The capacitor C2 plays a filtering role and improves the anti-interference performance of the system.

[0032] Pin 9 of main control chip 1 is connected to the +5V power output terminal, and pin 7 of main control chip 1 is connected to the negative terminal of DC 5V power supply; the other pins of main control chip 1 are connected to the corresponding functional units of the control board.

[0033] The main control chip 1 is an MCU main control chip, model PY32F003F18P6, which is the central control chip of the entire control system, controlling the communication, key detection, display driving and operation of the entire system.

[0034] The step-down converter circuit 5 includes resistors R4 and R5 and capacitor C3. One end of resistor R5 is connected to pin 1 of the main control chip 1. The other end of resistor R5 is connected to one end of resistor R4, one end of capacitor C3 and pin 1 of the terminal radar interface 8. The other ends of resistor R4 and capacitor C3 are connected to the negative terminal of the DC5V power supply.

[0035] The boost converter circuit 6 includes resistors R6, R7, and R8, NPN transistors Q3 and Q4. One end of resistor R6 is connected to pin 2 of the radar interface 8 terminal block, and the other end of resistor R6 is connected to the base of NPN transistor Q3. The collector of NPN transistor Q3 is connected to the base of NPN transistor Q4 and one end of resistor R7. The emitters of NPN transistor Q3 and NPN transistor Q4 are connected to the negative terminal of the DC 5V power supply. The collector of NPN transistor Q4 is connected to one end of resistor R8 and pin 2 of the main control chip 1. The other ends of resistors R7 and R8 are connected to the +5V power supply output terminal.

[0036] like Figure 5 As shown, when the data transmission pin TX1 (pin 1) of the main control chip 1 outputs a low level, the level at the other end of resistor R5 is also low, and the level at pin 1 (LD_RX) of the terminal block radar interface 8 is also low.

[0037] When the data transmission pin TX1 of the main control chip 1 outputs a 5V high level, resistors R5 and R4 form a voltage divider circuit. By adjusting the resistance values, the level at the other end of resistor R5 is made 3.3V, and the level at pin 1 (LD_RX) of the radar interface 8 terminal is also 3.3V. This converts the 5V pulse signal sent by the main control chip 1 into a 3.3V pulse signal, so that the radar module can normally receive the control data sent by the main control chip 1. Capacitor C3 acts as a filter to improve the anti-interference performance of the transmitted data.

[0038] When pin 2 (LD_TX) of the radar interface 8 of the terminal block outputs a low level, the NPN transistor Q3 is not turned on. The +5V power supply output is connected to the base of the NPN transistor Q4 through resistor R7. The base level of the NPN transistor Q4 is high, which turns on the NPN transistor Q4 and pulls the data receiving pin RX1 (pin 2) of the main control chip 1 to a low level.

[0039] When pin 2 (LD_TX) of the radar interface 8 outputs a 3.3V high level, NPN transistor Q3 is turned on, pulling the base level of NPN transistor Q4 low, thus turning off NPN transistor Q4. The +5V power supply output is connected to the data receiving pin RX1 (pin 2) of the main control chip 1 through resistor R8, thereby pulling the data receiving pin RX1 of the main control chip 1 to a 5V high level. This converts the 3.3V pulse signal sent by the radar module into a 5V pulse signal, so that the main control chip 1 can normally receive the control data sent by the radar module.

[0040] As described above, this control circuit can be used to achieve communication transmission between control systems with different voltages of 3.3V and 5V in a low-cost, stable and reliable manner.

[0041] The above describes the preferred embodiments of this utility model, illustrating and describing its basic principles, main features, and advantages. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made without departing from the spirit and scope of this utility model, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A low-cost control circuit for communication between 3.3V and 5V systems, characterized in that: It includes a main control chip (1), a voltage regulator module (2), a serial communication voltage conversion module (3), and a radar interface module (4). The main control chip (1) is electrically connected to the serial communication voltage conversion module (3) and the radar interface module (4). The power input terminal of the voltage regulator module (2) is electrically connected to the power supply. The power output terminal of the voltage regulator module (2) is electrically connected to the main control chip (1) and the serial communication voltage conversion module (3). The serial communication voltage conversion module (3) is electrically connected to the radar interface module (4).

2. The control circuit for low-cost communication between 3.3V and 5V systems according to claim 1, characterized in that: The serial communication voltage conversion module (3) includes a buck converter circuit (5) and a boost converter circuit (6). The buck converter circuit (5) is connected to the main control chip (1) and the radar interface module (4) respectively, and the boost converter circuit (6) is connected to the main control chip (1) and the radar interface module (4) respectively.

3. The control circuit for low-cost communication between 3.3V and 5V systems according to claim 2, characterized in that: The voltage regulator circuit module (2) includes a voltage regulator chip (7) and a resistor R1. One end of the resistor R1 is connected to the power supply, and the other end of the resistor R1 is connected to pin 2 of the voltage regulator chip (7). Pin 3 of the voltage regulator chip (7) is connected to the +5V power supply output terminal, and pin 1 of the voltage regulator chip (7) is connected to the negative terminal of the DC5V power supply.

4. The control circuit for low-cost communication between 3.3V and 5V systems according to claim 3, characterized in that: The voltage regulator circuit module (2) also includes electrolytic capacitor EC1, electrolytic capacitor EC2 and capacitor C1. One end of resistor R1 is connected to the positive terminal of electrolytic capacitor EC1, and the other end of resistor R1 is connected to one end of capacitor C1. Pin 3 of voltage regulator chip (7) is connected to the positive terminal of electrolytic capacitor EC2. The negative terminal of electrolytic capacitor EC1, the other end of capacitor C1 and the negative terminal of electrolytic capacitor EC2 are respectively connected to the negative terminal of DC5V power supply.

5. The control circuit for low-cost communication between 3.3V and 5V systems according to claim 4, characterized in that: The radar interface module (4) includes a terminal block radar interface (8) and a PMOS transistor Q1. Pin 1 of the terminal block radar interface (8) is connected to the communication receiving pin LD_RX of the radar module, pin 2 of the terminal block radar interface (8) is connected to the communication transmitting pin LD_TX of the radar module, pin 3 of the terminal block radar interface (8) is connected to the negative terminal of the DC5V power supply, pin 4 of the terminal block radar interface (8) is connected to the drain terminal of the PMOS transistor Q1, and the source terminal of the PMOS transistor Q1 is connected to the power supply.

6. The low-cost control circuit for communication between 3.3V and 5V systems according to claim 5, characterized in that: The radar interface module (4) also includes resistors R2 and R3 and NPN transistor Q2. The source of PMOS transistor Q1 is connected to one end of resistor R2, the gate of PMOS transistor Q1 is connected to one end of resistor R3, the other end of resistor R3 is connected to the other end of resistor R2 and the collector of NPN transistor Q2, the emitter of NPN transistor Q2 is connected to the negative terminal of DC5V power supply, and the base of NPN transistor Q2 is connected to pin 5 of the main control chip (1).

7. The control circuit for low-cost communication between 3.3V and 5V systems according to claim 2, characterized in that: The main control chip (1) is equipped with a filter circuit (9). The filter circuit (9) includes a capacitor C2. One end of the capacitor C2 is connected to the +5V power supply output terminal, and the other end of the capacitor C2 is connected to the negative terminal of the DC5V power supply.

8. The control circuit for low-cost communication between 3.3V and 5V systems according to claim 7, characterized in that: Pin 9 of the main control chip (1) is connected to the +5V power output terminal, and pin 7 of the main control chip (1) is connected to the negative terminal of the DC5V power supply.

9. The low-cost control circuit for realizing communication between 3.3V and 5V systems according to claim 6, characterized in that: The step-down converter circuit (5) includes resistor R4, resistor R5 and capacitor C3. One end of resistor R5 is connected to pin 1 of the main control chip (1). The other end of resistor R5 is connected to one end of resistor R4, one end of capacitor C3 and pin 1 of the terminal radar interface (8). The other end of resistor R4 and the other end of capacitor C3 are connected to the negative terminal of DC5V power supply.

10. The control circuit for low-cost communication between 3.3V and 5V systems according to claim 9, characterized in that: The boost converter circuit (6) includes resistors R6, R7, R8, NPN transistor Q3 and NPN transistor Q4. One end of resistor R6 is connected to pin 2 of the terminal block radar interface (8), and the other end of resistor R6 is connected to the base of NPN transistor Q3. The collector of NPN transistor Q3 is connected to the base of NPN transistor Q4 and one end of resistor R7. The emitter of NPN transistor Q3 and the emitter of NPN transistor Q4 are connected to the negative terminal of DC5V power supply. The collector of NPN transistor Q4 is connected to one end of resistor R8 and pin 2 of the main control chip (1). The other ends of resistor R7 and resistor R8 are connected to the +5V power supply output terminal.

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