The MAX3232 IC is frequently used to convert the TTL/CMOS logic levels to RS232 during the serial connection between a microcontroller and a computer. Therefore, to connect any microcontroller to a computer, we have to first transform the logic of TTL/CMOS to RS232. This post will share MAX3232 IC Pinout, configuration, Datasheet, Features, and Application for you.

Converting TTL to RS232 with the MAX3232 IC and using an Arduino to control send commands to a device with an RS232 port - eg. a projector. 

ⅠMAX3232 Product Detail

The MAX3232 transceivers have a proprietary low-dropout transmitter output stage enabling true RS-232 performance from a 3.0V to 5.5V supply with a dual charge pump. The devices require only four small 0.1µF external charge-pump capacitors. The MAX3232  is guaranteed to run at data rates of 120kbps while maintaining RS-232 output levels. 

Max3232 has two receivers and two drivers that provide 1uA shutdown mode, effectively reducing power efficiency and delaying 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 MAX3222   pin and package are functionally compatible with the industry-standard 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.

The  MAX3232 are available in space-saving TSSOP and SSOP packages with operating temperatures of either -40°C to +85°C or 0°C to 70°C.

Ⅱ MAX3232 Pinout

Figure1-MAX3232 pinout

Ⅲ MAX3232 Pinout Configuration

Ⅳ MAX3232 CAD Model

Symbol

Figure2-Symbol

Footprint

Figure3-Footprint

CAD Model

Figure4-CAD Model

ⅤMAX3232 Features and Specifications

It can work with 5V & 3.3V logic devices.

TTL to RS232 Converter IC.

It supports two conversions like Dual drivers & Receivers.

Simple to set up & initialize.

 Operating speed: 120kbit/s

 Operating current: 8mA

 Packages: 16-pin SO, PDIP & SOIC

Manufacturer: Texas Instruments.

TR Packaging (Tape and Reel).

The receiver of hysteresis is 300mV.

The status of the part is Active.

Package or Case: 16-SOIC.

Type: Transceiver

The type of mounting is surface mount.

RS232 Protocol.

The operating temperature ranges: from 0°C to 70°C.

The number of drivers is 2.

Voltage supply ranges from 3Volts to 5.5V.

The number of receivers is 2.

250kbps data rate.

Full duplex.

Note: Complete technical details can be found in the MAX3232 datasheet given at the end of the page.

Ⅵ Applications

When converting TTL or CMOS to RS232, use the MAX3232 IC.

Hand-Held device.

Utilized RS232 cables.

Palmtop personal computers.

Battery-operated systems.

Notebooks.

PDAs.

Laptops.

Ⅶ Typical Operating Circuits  and Simplified Schematic

Figure5-Typical Operating Circuits

Figure6-Simplified Schematic

Ⅷ How to use a MAX3232 Converter IC

This IC is simple to set up and operate. The IC requires 3.3V/+5V to function, therefore power the Vcc with the necessary voltage and connect the ground pin to the circuit ground. The four capacitors that the IC need to function can range in value from 1 uF to 22 uF.

The IC allows for the conversion of two logic levels, allowing for the usage of two microcontrollers, but for now, we'll simply use one MCU and connect it to a computer; the full circuit is illustrated below. As you can see, since we are not using the second module, the pins (T2 out, R2 in, T2 in, R2 out) are left open.

Figure7-MAX3232 Converter IC with Microcontroller

There are a Tx pin and an Rx pin serial in every microcontroller with serial communication capability. The T1 in (pin 10) and R1 out (pin 13) pins should be linked to these two pins, respectively. The converter RS232 logic signals can be acquired from the pin R1 in (pin 13) and T1 out, which are the TTL/CMOS logic inputs (pin 14). You may wonder how an IC powered by 3.3V/5V can transform a 3.3V/5V signal to a +25V signal. This is made feasible via a technique known as a charge pump, which uses a capacitor to store enough energy to provide 25V.

Ⅸ MAX3232 Package Outline

Figure8-MAX3232 Package Outline

Ⅹsp3232 vs max3232 vs max232

10.1 Sp3232 vs Max3232

It 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.

10.2 max3232 vs max232

What is max3232

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

What is max232

MAX232 chip is a single power supply level conversion chip designed by MAXIM for RS-232 standard serial port. It uses a +5v single power supply.

The device is particularly suitable for battery-powered systems because its low-power shutdown mode can reduce power consumption to less than 5uW.

Difference between MAX232 and MAX3232

MAX232 is 5V voltage, and the power consumption is higher than MAX3232, general civilian products use this.

MAX3232 is 3.3V, has low power consumption, and high performance, mainly used in aerospace and places where power consumption is very demanding.

There is no difference in performance between the two.

 1. MAX232 is powered by 5V voltage, and max3232 is powered by 5V or 3.3V voltage.

 2. The power consumption of MAX232 is large, when the supply voltage is 5V, the power consumption is 5mA; while the power consumption of MAX3232 is small, when the supply voltage is 5V or 3.3V, the power consumption is 0.3mA.

 3. MAX232 externally connected with four 1uF capacitors; while MAX3232 externally connected with four 0.1uF capacitors.

 4. MAX232 general civilian product application; and MAX3232 general military use (such as aerospace and other places with strict power consumption requirements).

 5. The price is slightly different.

Ⅺ MAX3232 PDF

MAX232 Datasheet