on January 17th 7,153

How MAX232 Simplifies RS-232 Communication?

The MAX232 is a widely used IC that enables communication between devices with different logic levels, such as microcontrollers and RS-232 devices. It works efficiently with a 5-volt supply and simplifies data transmission by converting TTL to RS-232 signals. This article provides a complete guide to its features, applications, and usage.

Catalog

MAX232 Overview

The MAX232 is a dual driver and receiver IC designed to convert TTL logic levels to RS-232 compatible levels. It uses a capacitive voltage generator to achieve this conversion while operating on a single 5-volt power supply. This IC is commonly used in applications requiring communication between microcontrollers and RS-232 devices. In this article, you’ll learn about its pin configuration, features, applications, and more to understand its functionality and uses.

MAX232 Pin Layout

MAX232 Pin Description

Pin Number	Pin Name	Description
1	C1 +	Connects to the positive end of the First capacitor
2	V+	Connects to one end of the capacitor & other end is grounded
3	C1 -	Connects to the negative end of First Capacitor
4	C2+	Connects to the positive end of the second capacitor
5	C2-	Connects to the negative end of the second capacitor
6	V-	Connects to one end of the capacitor & other end is grounded
7	T2 OUT	Transmission pin of second converter module for RS232 cable
8	R2 IN	Reception pin of second converter module for RS232 cable
9	R2 OUT	Reception pin of second converter module for Microcontroller(Rx)
10	T2 IN	Transmission pin of second converter module for Microcontroller(Tx)
11	T1 IN	Transmission pin of first converter module for Microcontroller(Tx)
12	R1 OUT	Reception pin of first converter module for Microcontroller(Rx)
13	R1 IN	Reception pin of first converter module for RS232 cable
14	T1 OUT	Transmission pin of first converter module for RS232 cable
15	Ground	Connects to the ground of the circuit
16	Vcc	Connects to the supply voltage typically +5V

MAX232 CAD Model

MAX232 Symbol

MAX232 Footprint

MAX232 3D Model

MAX232 Specifications

Technical specifications, features, characteristics, and components with comparable specifications of Texas Instruments MAX232

Type	Parameter
Lifecycle Status	ACTIVE (Last Updated: 2 days ago)
Factory Lead Time	6 Weeks
Mount	Through Hole
Mounting Type	Through Hole
Package / Case	16-DIP (0.300, 7.62mm)
Number of Pins	16
Weight	955.690774mg
Number of I/Os	8
Operating Temperature	-40°C~85°C
Packaging	Tube
JESD-609 Code	e4
Pbfree Code	Yes
Part Status	Active
Moisture Sensitivity Level (MSL)	1 (Unlimited)
Number of Terminations	16
ECCN Code	EAR99
Type	Transceiver
Terminal Finish	Nickel/Palladium/Gold (Ni/Pd/Au)
Voltage - Supply	4.5V~5.5V
Terminal Position	DUAL
Number of Functions	2
Supply Voltage	5V
Base Part Number	MAX232
Pin Count	16
Operating Supply Voltage	5V
Power Supplies	5V
Interface	RS-232
Nominal Supply Current	10mA
Propagation Delay	500 ns
Logic Function	Receiver, Transceiver
Data Rate	250kbps
Differential Output	NO
Output Polarity	INVERTED
Protocol	RS232
Input Characteristics	SCHMITT TRIGGER
Number of Drivers/Receivers	2/2
Receiver Number of Bits	2
Duplex	Full
Receiver Hysteresis	500mV
Number of Drivers	2
Number of Transceivers	1
Simplex/Duplex	Full Duplex
Supply Voltage1-Nom	5V
Height	5.08mm
Length	19.3mm
Width	6.35mm
Thickness	3.9mm
REACH SVHC	No SVHC
Radiation Hardening	No
RoHS Status	ROHS3 Compliant
Lead Free	Lead Free

Key Features of MAX232

Compliance with TIA/EIA-232-F and ITU Standards

The MAX232 is designed to meet or exceed the requirements of TIA/EIA-232-F and ITU Recommendation V.28. This ensures reliable communication in systems requiring these standards.

Operates with a Single 5-Volt Power Supply

This IC runs efficiently on a single 5-volt power supply, making it easy to use in a variety of circuits without needing additional power sources. It also requires only 1.0 μF charge-pump capacitors, reducing complexity.

Supports Data Rates Up to 120 kbit/s

With its ability to handle data rates up to 120 kbit/s, the MAX232 is suitable for applications requiring moderate-speed data transfer between devices.

Includes Two Drivers and Two Receivers

The IC features two drivers and two receivers, allowing it to handle both transmission and reception of signals simultaneously. This dual capability is helpful in many RS-232 communication setups.

Wide Input Voltage Range

It supports ±30-V input levels, making it versatile and adaptable to a variety of input signal requirements.

Low Power Consumption

The typical supply current of just 8 mA ensures the MAX232 operates with minimal power usage, which is ideal for battery-operated systems.

Enhanced ESD Protection

The IC provides ESD protection that exceeds JESD 22 standards, offering up to 2000 V human-body model (HBM) protection. This helps safeguard the IC from static electricity and other transient voltage spikes.

Upgrade Option with MAX202

For improved ESD protection up to 15-kV HBM and support for 0.1 μF charge-pump capacitors, the MAX202 can be used as an upgraded version of the MAX232.

Applications of MAX232

Battery-Powered RS-232 Systems

The MAX232 is ideal for use in RS-232 systems powered by batteries, as its low power consumption and efficient operation extend battery life.

Interface Translation

This IC is commonly used to translate logic levels between RS-232 and TTL/CMOS devices, making it useful in microcontroller-to-PC communication.

Low-Power Modems

Its low power requirements make the MAX232 a great choice for use in low-power modems, where conserving energy is important.

RS-232 Networks (Multi-Drop)

The IC supports RS-232 multi-drop networks, allowing multiple devices to communicate within the same system.

Portable Computing Devices

The MAX232’s compact design and efficient power usage make it suitable for portable computing devices that require RS-232 communication capabilities.

Usage Scenarios for MAX232

The MAX232 is a versatile IC often used to handle the conversion of RX, TX, CTS, and RTS signals in communication systems. It enables seamless communication by converting TTL/CMOS logic levels to RS-232 logic levels, which are standard for serial communication with devices like computers.

The drivers in the MAX232 generate TIA-232 voltage levels (approximately ±7.5 volts) from a single 5-volt supply. This is achieved with the help of on-chip charge pumps and external capacitors, making it a reliable and efficient choice for such conversions.

If you need to interface a microcontroller with a computer, the MAX232 provides an effective solution. Its ability to bridge the gap between the logic levels of these devices makes it a go-to component for such applications. Whether you are working on a basic project or a more complex system, this IC simplifies the communication setup.

How to Interface and Use MAX232

The MAX232 makes it easy to convert logic levels, allowing communication between devices like microcontrollers and computers. While it supports two logic level conversions, you can start with a single microcontroller and computer setup to get familiar with its functionality.

To connect, use the relevant pins for transmission (T1 IN and T1 OUT) and reception (R1 IN and R1 OUT) while leaving the secondary module pins (T2 OUT, R2 IN, T2 IN, R2 OUT) unconnected if not needed. This setup ensures a straightforward configuration while letting you focus on one connection at a time.

Equivalent Components for MAX232

• MC1488

• RS232 module

• FT232RL

• RS232 adapter cable

Comparison: MAX3232 vs. MAX232

The MAX3232 is often seen as an updated version of the MAX232, designed to offer more flexibility while maintaining compatibility. Both ICs share the same pinout and package style, making the MAX3232 a direct replacement for the MAX232 in most applications.

The key improvement in the MAX3232 is its ability to operate with both 3.3V and 5V systems, whereas the MAX232 is limited to 5V systems. This broader voltage support allows the MAX3232 to be used in modern low-voltage systems, making it a more versatile choice in some scenarios. Despite these differences, both ICs perform similar functions, making them interchangeable depending on your project’s voltage requirements.

Operational Details of MAX232

Preparing for Testing

Before beginning, ensure the tester is turned off to prevent any unintended power supply to the IC. This step is important for safety and proper testing.

Inserting the MAX232 Chip

Place the MAX232 chip into the ZIF (Zero Insertion Force) socket securely. Ensure it is properly aligned to avoid damage to the IC or socket.

Powering On the Tester

Push the SW1 button to turn the tester on. This activates the testing environment, allowing you to proceed with the functional checks.

Performing the Test

Press the test button on the tester. If the MAX232 is functioning as expected, a green LED will light up, indicating the IC is working correctly.

Testing the Serial Data Stream

Connect the IC to a COM port tester to verify its ability to transmit and receive data. When you press keys, the data stream should display in green, and it will echo back to the terminal in yellow, confirming proper operation.

Powering Off and Removing the Chip

Once testing is complete, push SW1 to turn off the tester. Carefully remove the MAX232 chip from the ZIF socket to conclude the process.

Physical Dimensions of MAX232

Manufacturer Information for MAX232

Texas Instruments, also known as TI, has been a leading name in the semiconductor industry since its founding in 1958. With over 30,000 employees worldwide, TI focuses on designing and producing analog components and embedded processing solutions. Operating in 35 countries, the company strives to innovate and provide reliable technology solutions for a variety of industries. TI’s dedication to advancing technology has made it a trusted manufacturer for products like the MAX232.

Parts with Similar Specifications to MAX232

The parts on the right have specifications similar to the Texas Instruments MAX232

Model	MAX232EIN	ADM202EANZ	ADM202JNZ	ADM1181AANZ
Manufacturer	Texas Instruments	Analog Devices Inc.	Analog Devices Inc.	Analog Devices Inc.
Package / Case	16-DIP (0.300, 7.62mm)	16-DIP (0.300, 7.62mm)	16-DIP (0.300, 7.62mm)	16-DIP (0.300, 7.62mm)
Number of Pins	16	16	16	16
Logic Function	Receiver, Transceiver	Receiver, Transceiver	Receiver, Transceiver	Receiver, Transceiver
Interface	RS-232	RS-232	RS-232	RS-232
Number of Drivers	2	-	2	2
Receiver Number of Bits	2	-	2	2
Data Rate	250kbps	230kbps	230kbps	120kbps
Supply Voltage	5 V	5 V	5 V	5 V

Datasheet PDF

ADM202EANZ Datasheet:

ADM202EANZ.pdf

ADM202JNZ Datasheet:

ADM202JNZ.pdf

ADM1181AANZ Datasheet:

ADM1181AANZ.pdf