Introduction to max3232

Max3232 uses a proprietary low dropout transmitter output stage for max3232, and uses dual charge pumps to achieve true RS-232 performance when powered by a 3.0V to 5.5V power supply. The device only requires four 0.1uF external small-size charge pump capacitors. max3232 ensures a data rate of 120kbps while maintaining the RS-232 output level.

Max3232 has two receivers and two drivers, provides 1uA shutdown mode, effectively reduces power efficiency and delays the battery life of portable products. In shutdown mode, the receiver maintains a valid state and monitors external devices. It only consumes 1uA of power supply current. The pins, packages and functions of max3232 are compatible with industry standards MAX242 and MAX232, respectively. Even at high data rates, max3232 can still maintain the minimum transmitter output voltage of plus or minus 5.0V required by the RS-232 standard.

Max3232 pin diagram

Max3232 pin function

As long as the input voltage is within the range of 3.0V to 5.5V, it can provide +5.5V (voltage double charge pump) and -5.5V (inverting charge pump) output voltages. The charge pump works in discontinuous mode. Once the output voltage is lower than 5.5V, the charge pump will be turned on; if the output voltage exceeds 5.5V, the charge pump can be turned off. Each charge pump requires a flying container and an energy storage capacitor to generate V+ and V- voltages.

Max3232 can guarantee a data rate of 120kbps under the worst working conditions. Under normal circumstances, it can work at a data rate of 235kbps, and the transmitter can drive multiple receivers and mice in parallel.

Max3232 function

Transceivers such as MAX3232 and MAX3222 use proprietary low-dropout transmitter output stages, and use dual charge pumps to achieve true RS-232 performance when powered by a 3.0V to 5.5V power supply. The max3232 supply voltage is 5v or 3.3V, which consumes power. 0.3mA, externally connected with 4 0.1uF capacitors.

About the stability of 232

When I was using MAX3232, there were a lot of hardware problems. I thought it was a software problem, but I found it was a hardware problem, which wasted a lot of time.

I used 2 serial ports, and then used MAX3232 to lead out 2 232 levels, but there was a problem with sending and receiving data, but there was no problem with the TTL level serial port. After comparing the same port, I found that when 232 was not used originally There is nothing, so it comes down to the month 232 problem, but it’s changed to 232

The difference between sp3232 and max3232

is a variant of the RS-232 standard, but the code system, baud rate, etc. are the same as the RS-232 definition, with only one difference, that is, the definition of high and low levels.

The high level of the single-chip microcomputer is generally VCC, and the low level is generally GND. The high level of the RS-232 standard is negative logic, and the low level is positive logic.

The computer’s COM port is a standard RS-232 interface. Its high level is defined as -12V, and its low level is defined as +12V. Therefore, the serial port of the single-chip microcomputer must undergo level conversion to communicate with the standard RS-232. The 5V converter chip is generally MAX232 or SP232, and the 3.3V chip is generally MAX3232 or SP3232.