b7V to a12V
t128 nodes t64 nodes t2 kV

December 1995

DS36C278

Low Power Multipoint EIA-RS-485 Transceiver

DS36C278 Low

General Description

The DS36C278 is a low power differential bus/line trans- ceiver designed to meet the requirements of RS-485 stan- dard for multipoint data transmission. In addition it is com- patible with TIA/EIA-422-B.

The CMOS design offers significant power savings over its bipolar and ALS counterparts without sacrificing ruggedness against ESD damage. The device is ideal for use in battery powered or power conscious applications. ICC is specified at 500 mA maximum.

The driver and receiver outputs feature TRI-STATEÉcapa- bility. The driver outputs operate over the entire common mode range of b7V to a12V. Bus contention or fault situa- tions that cause excessive power dissipation within the de- vice are handled by a thermal shutdown circuit, which forces the driver outputs into the high impedance state.

The receiver incorporates a fail safe circuit which guaran- tees a high output state when the inputs are left open.

The DS36C278T is fully specified over the industrial temper- ature range (b40§C to a85§C).

Features

Y100% RS-485 compliant

— Guaranteed RS-485 device interoperation

Y Low power CMOS design

ICC 500 mA max

YBuilt-in power up/down glitch-free circuitry

— Permits live transceiver insertion/displacement

YDIP and SOIC packages available

Y Industrial temperature range

b40§C to a85§C

YOn-board thermal shutdown circuitry

Prevents damage to the device in the event of ex- cessive power dissipation

Y Wide common mode range

YReceiver open input fail-safe

Y (/4 unit load (DS36C278)

Y (/2 unit load (DS36C278T)

Y ESD (human body model)

YDrop in replacement for:

— LTC485, MAX485, DS75176, DS3695

Power Multipoint EIA-RS-485

Connection and Logic Diagram

Truth Table

 

 

 

 

 

DRIVER SECTION

 

 

 

 

 

 

 

 

 

 

 

 

 

RE*

DE

 

DI

 

DO/RI

DO*/RI*

 

 

 

 

 

 

 

 

 

X

H

 

H

 

H

L

 

X

H

 

L

 

L

H

 

X

L

 

X

 

Z

Z

 

 

 

 

 

 

 

 

RECEIVER SECTION

 

 

 

 

 

 

 

 

 

 

RE*

DE

 

 

RI-RI*

RO

 

 

 

 

 

 

 

TL/F/12040 – 1

L

L

 

 

ta0.2V

H

Order Number DS36C278TM, DS36C278TN,

L

L

 

 

sb0.2V

L

DS36C278M, DS36C278N

H

L

 

 

 

X

Z

See NS Package Number M08A or N08E

 

 

 

L

L

 

 

OPEN

H

 

 

 

 

 

 

 

 

 

 

 

Note: Non-terminated, open input only

TRI-STATEÉis a registered trademark of National Semiconductor Corporation.

Transceiver

C1996 National Semiconductor Corporation

TL/F/12040

RRD-B30M36/Printed in U. S. A.

http://www.national.com

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National DS36C278 manual General Description, Features, Connection and Logic Diagram Truth Table, Open†

DS36C278 specifications

The National DS36C278 is a versatile and highly regarded dual/quad operational amplifier that has garnered attention for its impressive performance in various applications. As a member of the DS series, the DS36C278 integrates multiple features and technologies designed to meet the demands of both consumer and industrial electronics.

One of the main features of the DS36C278 is its high-speed operation. It boasts a wide bandwidth and fast slew rates, which make it suitable for applications requiring rapid signal processing. The amplifier typically operates with a bandwidth of up to 16 MHz, allowing it to handle high-frequency signals with ease. Its slew rate can reach up to 9 V/µs, ensuring quick transitions and faithful signal reproduction, ideal for video and audio applications.

The DS36C278 is designed for versatility, allowing it to function as either a dual or quad amplifier. This flexibility enables designers to streamline layouts and reduce component counts in their circuit designs, ultimately saving space on printed circuit boards. The dual and quad configuration is particularly beneficial in modular systems where multiple signal paths are required.

Another defining characteristic of the DS36C278 is its low noise operation. With a low input-referred noise density, this amplifier excels in applications where signal integrity is paramount. The design effectively minimizes distortion and interference, making it suitable for precision instrumentation and sensitive audio applications.

The device operates on a wide supply voltage range, typically from ±4.5 to ±15 volts, making it compatible with different power supply standards. This flexibility enhances its applicability in various contexts, from handheld devices to stationary equipment.

Furthermore, the DS36C278 is characterized by its thermal stability. The amplifier features a construction that reduces susceptibility to temperature fluctuations, allowing consistent performance across varying environmental conditions. This characteristic is crucial for industrial applications where temperature controls may be less stringent.

In summary, the National DS36C278 is a high-performance operational amplifier featuring dual/quad capabilities, high speed, low noise operation, and robust thermal stability. Its wide supply voltage range adds to its adaptability, making it a valuable component in numerous electronic designs, from consumer electronics to industrial applications. With its blend of features and technologies, the DS36C278 continues to be a preferred choice for engineers and designers seeking reliable amplification solutions.