CN215181496U

CN215181496U - USB changes four port UART circuits

Info

Publication number: CN215181496U
Application number: CN202121340533.6U
Authority: CN
Inventors: 徐明锋; 张琛星
Original assignee: Optofidelity High Tech Zhuhai Ltd
Current assignee: Optofidelity High Tech Zhuhai Ltd
Priority date: 2021-06-17
Filing date: 2021-06-17
Publication date: 2021-12-14
Anticipated expiration: 2031-06-17

Abstract

The utility model discloses a USB changes four port UART circuits aims at providing a USB of small, with low costs and multiple serial ports passageway changes four port UART circuits. The utility model comprises a power circuit, a serial port circuit, an EEPROM circuit, a clock circuit and an ESD protection circuit; the power supply circuit provides working voltage for each circuit module, the serial port circuit is a USB-to-serial port chip, and the EEPROM circuit, the clock circuit and the ESD protection circuit are all connected with the USB-to-serial port chip. The utility model discloses be applied to the technical field that USB changes four port UART circuits.

Description

USB changes four port UART circuits

Technical Field

The utility model relates to an interface conversion circuit, in particular to USB changes four mouthfuls of UART circuits.

Background

With the development of the times, electronic technologies are rapidly developed, various electronic products are produced more and more, the consumption of the electronic products is rapidly upgraded, and the requirements of customers on the performance and parameters of the purchased products are higher and higher. In order to meet various requirements, manufacturers need to make more detailed requirements on various parameters of products, and in order to ensure the correctness of data, the parameters need to be accurately measured when the products are delivered from factories. This requires the manufacturer to have detailed test data on the performance parameters of the product before the product leaves the factory to ensure the stability of the product performance. Therefore, before shipment, the product needs to be subjected to rigorous testing to ensure that the product performance meets the standard. Many products have various functions, so a main control chip is needed to process and control the functions, and when the functions of the products are required to be tested, the functions are coordinated through hardware and software, a test environment is built through the hardware, and the functions are processed through software instructions; the communication modes of the existing hardware products include serial port communication, internet access communication, Bluetooth communication and the like, and the serial port communication has the advantages that the hardware interface is simple, the program compiling is simple, the computer can be used for displaying relevant debugging information, the program debugging can be conveniently carried out without other external hardware, and therefore the use is more.

Aiming at the existing serial port module product, the following defects mainly exist:

1. the volume is great, and the cost is on the high side: the serial port module is a packaged product, so that the size is increased, the cost is high, the serial port module is mainly used for offline debugging and is not suitable for special occasions such as a plurality of automatic production lines;

2. the serial port channels are few: most serial port modules only have 1 channel, and can not satisfy the demand of communicating a plurality of products simultaneously, and the module that needs to increase when a plurality of products communicate then can increase the cost.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that overcome prior art not enough, provide a USB of small, with low costs and multiple serial ports passageway changes four port UART circuit.

The utility model adopts the technical proposal that: the USB-to-four-port UART circuit comprises a power supply circuit, a serial port circuit, an EEPROM circuit, a clock circuit and an ESD protection circuit; the power supply circuit provides working voltage for each circuit module, the serial port circuit is a USB-to-serial port chip, and the EEPROM circuit, the clock circuit and the ESD protection circuit are all connected with the USB-to-serial port chip.

Further, the model of the USB-to-serial port chip is FT4232 HL.

Furthermore, the power supply circuit takes USB _ +5V as input voltage, and the USB _ +5V is the voltage to the USB port of the computer, and is connected to the circuit through a USB line when in use; the power supply circuit comprises a power supply management chip U2, and the power supply management chip U2 provides stable input voltage for each circuit; the power supply circuit further comprises a diode D1, wherein the anode of the diode D1 is connected with the output end of the power management chip U2, the cathode of the diode D1 is connected with the input end of the power management chip U2, and the diode D1 is used for protecting the power management chip U2 and protecting the input from being instantaneously shorted to GND so as to prevent the power management chip U2 from being damaged; the power supply circuit comprises an isolation filter circuit, the isolation filter circuit comprises input end filter capacitors C1 and C2 and output end filter capacitors C6 and C7, the input end filter capacitors C1 and C2 are arranged in parallel, one ends of the input end filter capacitors C1 and C2 are connected with the input end of the power supply management chip U2, one ends of the output end filter capacitors C6 and C7 are connected with the output end of the power supply management chip U2, the other ends of the input end filter capacitors C1 and C2 and the other ends of the output end filter capacitors C6 and C7 are grounded, and the isolation filter circuit is used for filtering high-frequency interference signals and reducing power supply noise; the isolation filter circuit further comprises a power output indicator lamp LED1 and an LED current-limiting resistor R2, the anode of the power output indicator lamp LED1 is connected with the output end of the power management chip U2, and the cathode of the power output indicator lamp LED1 is connected with the LED current-limiting resistor R2 in series and then is grounded.

Further, the EEPROM circuit is an electrified erasable programmable read-only memory chip, the EEPROM circuit is a 93LC46B chip U3, and a plurality of pull-up resistors R3, R4, R6 and R8 are connected to the 93LC46B chip U3.

Further, the clock circuit consists of a 12M crystal oscillator X1 and two capacitors C14 and C15; the two capacitors C14 and C15 are arranged in parallel, one ends of the two capacitors C14 and C15 are respectively connected with two ends of the 12M crystal oscillator X1, and the other ends of the two capacitors C14 and C15 are both grounded.

Further, the ESD protection circuit comprises an ESD protection chip U1, the model of the ESD protection chip U1 is NUP4202W1, and the USB serial-to-serial port chip is prevented from being damaged by static electricity; the ESD protection circuit further comprises a USB socket J1, the ESD protection chip U1 and the USB socket J1 are connected, and the USB socket J1 is connected to a computer to provide power and USB signals for a circuit board.

The utility model has the advantages that: the utility model adopts a design of converting USB to four-port UART, comprising a power circuit, a serial circuit, an EEPROM circuit, a clock circuit and an ESD protection circuit; the power supply circuit provides working voltage for each circuit module, the serial port circuit is a USB-to-serial port chip, the EEPROM circuit, the clock circuit and the ESD protection circuit are all connected with the USB-to-serial port chip, therefore, the design is realized by selecting related circuits of key chip design, unnecessary devices are eliminated, the layout is optimized, the size is reduced, 1 group of chips with USB signals transferred out of four serial ports is used for designing a hardware circuit, more serial port equipment can be generated under the condition of limited USB signal resource conditions, the use is simple, only a USB wire needs to be used, one end of the USB wire is connected to a computer, the other end of the USB wire is connected to the built serial port circuit board, four independent serial port equipment can be found on the computer, and the debugging on the computer is also convenient.

Drawings

FIG. 1 is a block diagram of the system of the present invention;

fig. 2 is a power supply circuit of the present invention;

fig. 3 is a serial port circuit of the present invention;

FIG. 4 is an EEPROM circuit of the present invention;

fig. 5 is a clock circuit of the present invention;

fig. 6 shows an ESD protection circuit according to the present invention.

Detailed Description

In this embodiment, the utility model discloses constitute by power supply circuit, serial circuits, EEPROM circuit, clock circuit, ESD protection circuit.

FIG. 1 is a block diagram of a design system in which a power supply circuit provides operating voltages for various circuit blocks; the serial port circuit is a USB-to-serial port chip; the ESD protection circuit prevents the chip from being damaged by static electricity; the clock circuit consists of a 12M crystal oscillator and two capacitors; the EEPROM circuit uses 93LC46B chips, which can be programmed via USB using FT _ PROG software.

FIG. 2 shows a power supply circuit, which converts the input voltage into the working voltage required by each circuit module to provide stable and low-noise power supply voltage for each module, wherein the power supply circuit uses USB _ +5V as the input voltage, and USB _ +5V is the voltage to the USB port of the computer, and is connected to the circuit through a USB cable when in use. The circuit comprises a power supply management chip, a D1 diode, a C1, a C2, a C6 and a C7 isolation filter circuit, wherein the U2 in the circuit is the power supply management chip and provides stable input voltage for each circuit; LED1 is the power output pilot lamp, and R2 is LED current-limiting resistance.

Fig. 3 shows a serial port circuit, which converts USB signals into serial port signals, and converts a group of USB signals into four paths of serial port signals. U4 in the circuit is a serial port chip for converting USB into 4 channels; C8-C13 and C16-C22 which are isolation filter circuits and are used for filtering high-frequency interference signals and reducing power supply noise; and R12-R19 are serial port chip output end matching resistors and are connected with external equipment.

FIG. 4 is an EEPROM circuit, which is 93LC46B chip, which can be programmed by USB using FT _ PROG software, and U3 is an EEPROM chip; r3, R4, R6 and R8 are pull-up resistors; the external EEPROM can be used for customizing VID, PID and serial number of the USB, and can also be used for modifying serial port name and power supply descriptor value of FT4232H, remote awakening, power-off soft pull-down, I/O pin driving strength and the like.

In the clock circuit shown in fig. 5, a clock selection passive crystal oscillator provides a reference frequency for a serial port chip, X1 is a 12M passive crystal oscillator, and C14 and C15 are load capacitors.

Fig. 6 shows an ESD protection circuit, U9 shows an ESD protection IC, which prevents the chip from being damaged by static electricity; j1 is a USB socket connected to a computer to supply power and USB signals to the circuit board.

The embodiment has the following advantages: 1. the size of the serial port module is reduced, and the serial port name is easy to modify; 2. the cost of using a single serial port module is reduced; 3. and multi-channel serial port communication is realized.

The utility model discloses a select a section high-speed, multichannel serial ports chip, design power supply circuit, clock circuit, ESD protection circuit, EEPROM circuit accomplishes the output of buildding in order to realize four ways serial ports signal of hardware circuit.

While the embodiments of the present invention have been described in terms of practical embodiments, they are not intended to limit the scope of the invention, and modifications of the embodiments and combinations with other embodiments will be apparent to those skilled in the art in light of the present description.

Claims

1. A USB changes four port UART circuit, its characterized in that: the USB-to-four-port UART circuit comprises a power supply circuit, a serial port circuit, an EEPROM circuit, a clock circuit and an ESD protection circuit; the power supply circuit provides working voltage for each circuit module, the serial port circuit is a USB-to-serial port chip, and the EEPROM circuit, the clock circuit and the ESD protection circuit are all connected with the USB-to-serial port chip.

2. The circuit of claim 1, wherein the circuit comprises: the model of the USB-to-serial port chip is FT4232 HL.

3. The circuit of claim 1, wherein the circuit comprises: the power circuit takes USB _ +5V as input voltage, the USB _ +5V is voltage to a USB port of a computer, and the power circuit is connected to the circuit through a USB line when in use; the power supply circuit comprises a power supply management chip (U2), and the power supply management chip (U2) provides stable input voltage for each circuit; the power supply circuit further comprises a diode (D1), wherein the anode of the diode (D1) is connected with the output end of the power management chip (U2), the cathode of the diode (D1) is connected with the input end of the power management chip (U2), and the diode (D1) is used for protecting the power management chip (U2) and protecting the input from being instantaneously shorted to GND so as to prevent the power management chip (U2) from being damaged; the power supply circuit comprises an isolation filter circuit, the isolation filter circuit comprises an input end filter capacitor (C1, C2) and an output end filter capacitor (C6, C7), the input end filter capacitor (C1, C2) is arranged in parallel, one end of the input end filter capacitor (C1, C2) is connected with the input end of the power management chip (U2), one end of the output end filter capacitor (C6, C7) is connected with the output end of the power management chip (U2), the other end of the input end filter capacitor (C1, C2) and the other end of the output end filter capacitor (C6, C7) are grounded, and the isolation filter circuit is used for filtering high-frequency interference signals and reducing power supply noise; the isolation filter circuit further comprises a power output indicator lamp (LED 1) and an LED current-limiting resistor (R2), the anode of the power output indicator lamp (LED 1) is connected with the output end of the power management chip (U2), and the cathode of the power output indicator lamp (LED 1) is grounded after being connected with the LED current-limiting resistor (R2) in series.

4. The circuit of claim 1, wherein the circuit comprises: the EEPROM circuit is a charged erasable programmable read-only memory chip, the EEPROM circuit is a 93LC46B chip (U3), and a plurality of pull-up resistors (R3, R4, R6 and R8) are connected to the 93LC46B chip (U3).

5. The circuit of claim 1, wherein the circuit comprises: the clock circuit consists of a 12M crystal oscillator (X1) and two capacitors (C14, C15); the two capacitors (C14, C15) are arranged in parallel, one ends of the two capacitors (C14, C15) are respectively connected with two ends of the 12M crystal oscillator (X1), and the other ends of the two capacitors (C14, C15) are grounded.

6. The circuit of claim 1, wherein the circuit comprises: the ESD protection circuit comprises an ESD protection chip (U1), the model of the ESD protection chip (U1) is NUP4202W1, and the USB serial-to-serial port chip is prevented from being damaged by static electricity; the ESD protection circuit further comprises a USB socket (J1), the ESD protection chip (U1) and the USB socket (J1), and the USB socket (J1) is connected to a computer to provide power and USB signals for a circuit board.