1, MAX232 pin functions are as follows: Pin 1: C1, pin 2: V, pin 3: C1-Pin 4: C2, pin 5Feet: C2- Foot 6: V- Foot 7: T2OUT Foot 8: R2IN Foot 9: R2OUT Foot 10: T2IN Foot 11: T1IN Foot 12: R1OUT Foot 13: R1IN Foot 14: T1OUT Foot 15: GND Foot 16: GND The Vcc attachment is the official data book of the chip.
2, MAX232 and MAX202E chips are specially designed for the computer RS-232 standard serial port interface circuit, using 5v single power supply. MAX232 and MThe AX202 pins are fully compatible, basically the same function, and can be replaced with each other. If you want to distinguish on the circuit board, but the working temperature is not the same. The internal structure can be basically divided into three parts: the first part is the charge pump circuit. It consists of 6 pins and 4 capacitors.
3, because the output voltage of the computer serial port is as high as 12V, the direct connection with the MCU will burn the chip. So MAX232 is used for level conversion. The MAX232 chip uses a single 5V power supply, and only a few external capacitors can complete the conversion from TTL to RS232 level, a total of two ways. A typical circuit is shownAX3232: High-performance RS-232 conversion chip '> Domestic MAX3232: High-performance RS-232 conversion chip
MAX3232 as a classic 232 interface chip RS-232 conversion chip 232 interface chip , plays an important role in serial communication. However, due to the growing market demand for localization and independent innovation, the domestic MAX3232 came into being. Domestic MAX3232 adopted 232 interface chip Advanced process and design, with performance and reliability comparable to international brands. It supports standard RS-232 level conversion, can operate stably in industrial environment, and has good anti-interference ability.
Domestic max3232 is a commonly used RS-232 conversion chip, which is widely used in serial communication equipment, such as computers, industrial control equipment, communication equipment and so on. This chip has the characteristics of stable performance and reliable quality, and has been favored by many manufacturers and users.
MAX3232CSEIt is a common level conversion chip used to realize RS-232 standard serial communication. The chip is manufactured by Maxim and is part of the MAX3232 family.
This is an RS232 interface chip, each chip has 3 transmitters and 5 receivers, and the working power supply voltage is 3V~5V.
MAX3243 is also an RS232 interface, which is used for data transmission. Its workThe voltage range is 3V~5V, and the internal structure is 3 output drivers and 5 receivers (3 send and 5 receive).
Maybe you have not welded well, 1IBM T23 MAX1631 no control signal IBMT23 power chip MAX1631 22 pin has 16V voltage. 23 pin No 5V control voltage. 23 pin without 5V, other feet have no output, MAX1631 does not work the same. Pin 23 is controlled by TB6808F. Test TB6808F with 16V input and no output. Change TB6808F, turn it on, andI can't.
Rs 232 driver chip, that is, the process of level conversion, TTL level and CMOS level interconversion. Our commonly used MCU 232 interface is TTL level, and our computer 232 interface, are CMOS, how to make TTL level and CMOS level match, the middle can only add conversion chip to complete.
MAX232 chip is a single power level conversion chip designed for RS-232 standard serial port by MAXIM company, using 5v single power supply. The MAX220-MAX249 series line drivers/receivers are designed for EIA/TIA-232E and V.28/V.24 communication interfaces, especially in applications where ±12V power is not available. These devices are particularly suitable for battery-powered systems due to their low-power shutdown mode, which reduces power consumption to less than 5uW.
RS-232 is intended for point-to-point (i.eA pair of receiving and sending equipment) designed for communication, the driver load is 3 ~ 7kΩ. So RS-232 is suitable for communication between local devices.
Transmission distance Different RS-232 is suitable for communication between local devices, and the transmission distance is generally not more than 20m. The transmission distance of RS-485 is tens of meters to thousands of meters. RS-232 only allows one-to-one communication, while RS-485 interfaces allow up to 128 transceivers on the bus.
RS422, using TTL differential level to represent the logic, is the voltage of the twoThe difference represents the logic, RS422 is defined as full-duplex, so at least 4 communication lines (generally an additional ground wire), a driver can drive up to 10 receivers (that is, the receiver is 1/10 unit load), the communication distance is related to the communication rate, the general distance can use a high rate of communication for a short time. Long distance communication is possible at low speeds.
max232 is a standard RS232 communication connectionOn the one hand, the TTL level of the transmitted data is converted to RS232 level to send out, on the other hand, the received RS232 level of the data is converted to TTL level, usually TTL level end is the chip on the MCU or computer motherboard, and RS232 level end is generally DB9 head, which is the COM port on the computer. Summary; Is to convert TTL level to RS232 level.
RS232 is an interface, which is usually called a serial port. When communicating on the RS232 interface, the voltage of 12V can be identified, and the relative high and low level is 12V and 0V, but the high and low level of 51 MCU is 5V and 0V, and the level of 2 is not the same, so a level conversion chip is needed in the middle to translate, and MAX232 acts as this. USB serial port refers to a device that can convert USB signals into serial signals.
MAX232 is a common RS-232 level conversion chip. MAX232 is an RS-232 standard serial communication level conversion chip launched by Maxim. The RS-232 level standard refers to the voltage from 5V to 15V to represent the logic state, while the computer is used internallyTTL levels of 0 to 5V indicate logical state.
It is responsible for converting the 5V high level output of the single chip microcomputer into -12~-5V; It is also responsible for converting the low level of 0V MCU into 5~ 12, and vice versa, converting the PC signal into 0V or 5V level, which is the role of MAX232, as for how MAX232 does these things, the principle of charge pump is what, it is not here verbose, Baidu a MAX232 data manual will know, The above hope is useful for you.
1, a 232 port can be extended to multiple 232 chips. A 232 chip is an integrated circuit that implements a 232 interface, which can be used to transfer data between a computer and a specific device. 232 chips provide a convenient way to transfer data between a computer and external devices such as printers, terminals, and external memory. They use the 232 interface and can transmit data in bytes or microcontroller data format. The 232 chip supports a maximum baud rate of 115,200.
2Only point-to-point communication is supported, that is, a 232 interface can only connect to one 232 device. 485 supports point-to-multipoint communication, so you can connect to multiple devices. If you have to connect to multiple 232 devices, you need to add a 232 hub (also known as a distributor), you can extend a 232 port to multiple 232 devices, and then you can connect to multiple 232 devices. There are 4 mouths and 8 mouths common on the market, and the price is about 100-200.
3, RS-232 serial port expansion chip: This chip is mainly used to achieve computer serial communication interfaceExpand. RS-232 protocol is widely used in the field of computer serial communication, because the number of serial ports in the computer is limited, it is necessary to use serial port expansion chip to increase the number of serial ports. The RS-232 serial port expansion chip can connect multiple external serial port devices to the computer to facilitate data transmission and communication.
4, with the serial port expansion chip, WK2204 or WK2168, through the SPI/I2C/UART/ 8-bit bus to expand 4 serial ports, the chip supports RS485 automatic transceiver, through the extended UART connected to RS232 and RS485 level conversion coreA tablet will do. WK2204 and WK2168 both have RS485 automatic transceiver function, which is very convenient.