on February 18th 309

Why Choose MAX250CSD for Serial Communication Projects

The MAX250CSD gives you a simple way to connect modern logic circuits to classic RS-232 serial ports. With built-in drivers and receivers, it handles both transmit and receive paths in one small package. You can run it from a single 5V supply, and it even creates the required RS-232 voltage levels internally. That means fewer external parts and an easier layout. Whether you're linking a control board to a PC or adding a serial port to your system, this chip keeps things clean and reliable. Its full duplex design lets you send and receive data at the same time without extra switching. In this guide, you’ll explore its features, pin details, internal structure, and common applications.

Catalog

MAX250CSD Overview

The MAX250CSD is a full duplex RS 232 transceiver designed to connect CMOS and TTL logic levels to standard serial communication ports. It integrates two line drivers and two line receivers in a 14 pin SOIC package, supporting bidirectional data exchange through a single 5 volt supply. An internal charge pump generates the required positive and negative output voltages for RS 232 signaling without the need for dual power rails. The device is suited for embedded systems, industrial controls, and legacy serial equipment that require reliable port conversion. Looking for MAX250CSD? Contact us to check current stock, lead time, and pricing.

MAX250CSD Pinout Details

MAX250CSD Pin Description

Pin Number	Pin Name	Description
1	SHDN	Shutdown input, logic control to disable the device and reduce power consumption
2	D1	Driver 1 output, RS-232 level output
3	T1LDR	Transmitter 1 load driver control
4	T1IN	Transmitter 1 input, TTL/CMOS logic input
5	T2IN	Transmitter 2 input, TTL/CMOS logic input
6	T2LDR	Transmitter 2 load driver control
7	GND	Ground reference
8	EN	Enable input, enables normal device operation
9	R1OUT	Receiver 1 output, TTL/CMOS logic output
10	R1DIN	Receiver 1 input, RS-232 level input
11	R2DIN	Receiver 2 input, RS-232 level input
12	R2OUT	Receiver 2 output, TTL/CMOS logic output
13	D2	Driver 2 output, RS-232 level output
14	VCC	Positive supply voltage, 4.5V to 5.5V

MAX250CSD CAD Model

MAX250CSD Symbol

MAX250CSD Footprint

MAX250CSD 3D Model

Features of MAX250CSD

RS 232 Communication Support

The MAX250CSD is designed to meet standard RS 232 electrical specifications for serial data exchange. It converts low level CMOS and TTL logic signals into RS 232 voltage levels for transmission, and converts incoming RS 232 signals back into logic level outputs. This allows direct connection between digital circuits and traditional serial ports without external level shifting components. The device supports reliable communication across typical serial data rates used in embedded and control systems.

Dual Channel Communication

The MAX250CSD integrates two line drivers and two line receivers in a single package. This 2 by 2 configuration enables two independent transmit and receive paths, supporting full duplex data transfer. Each driver and receiver operates as a matched pair, allowing simultaneous sending and receiving of data between connected devices. This structure reduces the need for separate interface components and simplifies board layout.

Full Duplex Data Transmission

The device supports full duplex communication, which allows data to be transmitted and received at the same time. This mode improves communication efficiency in systems that require continuous two way data flow. It eliminates the need to alternate between transmit and receive states, which helps maintain stable and uninterrupted serial communication.

Single 5 V Supply Operation

The MAX250CSD operates from a single supply voltage between 4.5 volts and 5.5 volts. An internal charge pump generates the positive and negative voltage levels required for RS 232 signaling. This removes the need for dual power supplies and reduces external component count. The simplified power requirement supports compact and straightforward circuit design.

Receiver Hysteresis for Noise Tolerance

Each receiver includes approximately 600 millivolts of input hysteresis. This feature improves resistance to noise and slow signal transitions on the RS 232 input lines. It helps prevent false switching and unstable output levels in environments where electrical interference may be present. As a result, logic outputs remain stable during normal operating conditions.

14 Pin SOIC Surface Mount Package

The MAX250CSD is housed in a 14 pin SOIC surface mount package. This compact format supports efficient use of printed circuit board space and is suitable for automated assembly processes. The package design allows reliable solder connections and consistent mechanical placement in standard surface mount layouts.

Commercial Temperature Range Operation

The device is specified for operation from 0 degrees Celsius to 70 degrees Celsius. This temperature range supports use in commercial and indoor electronic equipment. It maintains stable performance within this range when operated under recommended supply and load conditions.

CMOS and TTL Logic Compatibility

The MAX250CSD is compatible with standard CMOS and TTL logic levels. It can interface directly with microcontrollers, digital processors, and other logic based systems without additional signal conditioning. This compatibility simplifies integration into a wide range of digital designs that require RS 232 communication.

MAX250CSD Technical Specifications

Product Attribute	Attribute Value
Manufacturer	Maxim Integrated
Voltage - Supply	4.5V ~ 5.5V
Type	Transceiver
Supplier Device Package	14-SOIC
Receiver Hysteresis	600 mV
Protocol	RS232
Package / Case	14-SOIC (0.154', 3.90mm Width)
Package	Tube
Operating Temperature	0°C ~ 70°C
Number of Drivers/Receivers	2/2
Mounting Type	Surface Mount
Duplex	Full
Base Product Number	MAX250
RoHS Status	RoHS non-compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)
REACH Status	REACH Unaffected
ECCN	EAR99
HTSUS	8542.39.0001

Block Diagram of MAX250CSD

Internal architecture arranged around a dual transmitter and dual receiver configuration powered from a single 5 V supply. An on-chip 300 kHz RC oscillator feeds a divide by two stage that drives a charge pump, generating the positive and negative voltage levels required for RS-232 signaling. Two transmitter paths accept TTL or CMOS inputs at T1IN and T2IN, pass through logic control and driver stages, and deliver RS-232 outputs at D1 and D2 with associated load driver control pins. Two receiver channels accept RS-232 inputs at R1DIN and R2DIN, process them through comparator stages with defined bias currents, and provide logic-level outputs at R1OUT and R2OUT. Control inputs including SHDN and EN manage oscillator operation and channel enable functions, while VCC and GND define the device supply and reference nodes.

Chip Topographies of MAX250CSD

Die layout of the MAX250CSD showing internal circuit regions and bond pad placement corresponding to the 14 external pins. Peripheral pads are labeled SHDN, VCC, D1, D2, T1IN, T2IN, R1DIN, R2DIN, R1OUT, R2OUT, EN, and GND, matching the package pinout. Four large symmetric regions occupy the central area, associated with the dual transmitter and dual receiver channels, while smaller control and bias circuitry is distributed between them. Measured die dimensions are approximately 0.079 inches by 0.067 inches, indicating the physical silicon size within the package. The arrangement reflects separation between high voltage driver sections and lower voltage logic and control blocks.

Applications of MAX250CSD

PC Serial Port Communication Interfaces

The MAX250CSD is used to connect embedded boards and digital subsystems to standard PC serial ports. It converts 5 volt logic signals into RS 232 voltage levels that desktop and laptop serial connectors require. This allows firmware updates, configuration settings, and diagnostic data to be exchanged through a direct serial link. Its full duplex structure supports simultaneous transmit and receive paths, which keeps communication stable during continuous data transfer.

Industrial Equipment with RS 232 Connectivity

Many industrial machines include RS 232 ports for setup, calibration, and monitoring tasks. The MAX250CSD provides the signal translation between internal control logic and external serial connectors. It supports reliable two way communication for sending commands and receiving status information. With a single 5 volt supply and internal voltage generation, it fits easily into compact control boards used in factory and process equipment.

Point Of Sale Systems

Point of sale terminals often communicate with printers, scanners, and cash drawers through serial connections. The MAX250CSD enables the main processing unit to interface directly with these RS 232 based peripherals. Its dual driver and receiver configuration allows transaction data to be transmitted while acknowledgments are received at the same time. This supports smooth data flow during payment processing and receipt printing.

Data Communication Terminals

In data terminals that rely on serial links, the MAX250CSD manages the conversion between internal digital signals and external RS 232 lines. It maintains proper voltage levels on both transmit and receive paths, allowing structured data to move between devices without signal mismatch. This makes it suitable for terminals used in identification systems, access control units, and field data collection equipment.

Embedded Systems Requiring Legacy RS 232 Interface

Some embedded designs continue to include RS 232 ports for compatibility with existing infrastructure. The MAX250CSD allows modern CMOS and TTL logic circuits to connect directly to these legacy interfaces. It supports configuration ports, service connections, and communication with older equipment while operating from a single regulated supply. This approach preserves backward compatibility without adding complex external circuitry.

Telecommunications Equipment with Standard Serial Ports

Telecommunications devices often use serial ports for diagnostics and system control. The MAX250CSD provides the required voltage level translation between internal logic circuits and external RS 232 connectors. It supports steady bidirectional communication for command exchange and status reporting. Its compact surface mount package allows integration into communication boards where space and layout efficiency are controlled.

Outline Dimensions of MAX250CSD

Mechanical outline drawing defining the 14 lead small outline package used for the MAX250CSD. The diagram provides top, side, and end views with dimensional tolerances in inches and millimeters, including overall body length, body width, lead pitch of 0.050 inches BSC, and lead width and thickness ranges. Seating plane height, standoff dimensions, and lead bend angle are specified to support PCB footprint design and assembly. Lead 1 identification is marked to ensure correct orientation during placement. Thermal characteristics are listed with θJA of 115 degrees C per watt and θJC of 60 degrees C per watt, indicating junction to ambient and junction to case thermal resistance for thermal analysis.

MAX250CSD Advantages and Disadvantages

Advantages

• Integrates two drivers and two receivers in one package, reducing external components

• Supports full duplex communication for simultaneous transmit and receive operation

• Includes 600 mV receiver hysteresis for improved noise tolerance

• Operates from a single 5 V supply, simplifying power requirements

• Available in a compact 14 pin SOIC package for space efficient layouts

• Well suited for systems that rely on established RS 232 serial standards

Disadvantages

• Limited to RS 232 communication protocol

• Specified for operation only within 0 C to 70 C temperature range

• Requires a 5 V supply, not directly compatible with 3.3 V logic systems

• Not aligned with newer low voltage serial interface standards

• Not compliant with RoHS material restrictions

MAX250CSD Alternatives

Part Number	Manufacturer	Key Features	Use Case/Notes
MAX250CSD+G55	Analog Devices Inc./Maxim Integrated	Dual RS-232 transceiver operating from a single 5 V supply. Provides two drivers and two receivers with built-in hysteresis for improved noise immunity and stable full-duplex communication.	Used in embedded systems, industrial controllers, and serial communication interfaces requiring reliable RS-232 connectivity.
MAX250CSD+	Analog Devices Inc./Maxim Integrated	RS-232 transceiver with integrated charge pump, supporting 4.5 V to 5.5 V supply range. Designed for full-duplex operation with improved signal integrity.	Suitable for communication modules, microcontroller interfaces, and legacy serial port applications.
MAX250CSD+T	Analog Devices Inc./Maxim Integrated	Dual driver/receiver RS-232 interface IC packaged for automated assembly. Provides stable data transmission and supports standard serial communication levels.	Commonly used in compact PCB designs for data acquisition, instrumentation, and communication equipment.
MAX250CPD	Analog Devices Inc./Maxim Integrated	RS-232 transceiver supporting dual drivers and receivers with reliable 5 V operation. Designed for stable full-duplex communication in surface-mount format.	Appropriate for industrial communication boards, serial interface adapters, and embedded system connectivity.

About Maxim Integrated

Maxim Integrated Products, Inc. was founded in 1983 and established its headquarters in San Jose, California. The company specialized in the design and development of analog and mixed signal integrated circuits for a wide range of electronic systems. Its product portfolio covered power management, signal processing, data conversion, and interface solutions used in industrial, automotive, communications, medical, and consumer applications. In 2021, Maxim Integrated became part of Analog Devices, Inc., expanding its technological resources and global reach within the semiconductor industry.

Conclusion

The MAX250CSD helps you bridge the gap between 5V logic and traditional RS-232 serial ports without adding complex circuits. With two drivers and two receivers inside a compact 14-pin SOIC package, it supports smooth full duplex communication. Its internal charge pump removes the need for dual power supplies, which keeps your design simple. You also get built-in noise tolerance thanks to receiver hysteresis, helping maintain stable data transfer. From embedded boards to serial-based equipment, it fits easily into many setups. If you need a reliable and straightforward RS-232 interface solution, this device gives you a clean and practical option.

Datasheet PDF

MAX250CSD Datasheet:

MAX250CSD.pdf

MAX250CSD.pdf

MAX250CSD.pdf

MAX250CSD.pdf

MAX250CSD.pdf