ADM1485AQ Analog Devices, ADM1485AQ Datasheet

ADM1485AQ

Manufacturer Part Number

ADM1485AQ

Description

+-5 V Low Power EIA RS-485 Transceiver

Manufacturer

Analog Devices

Datasheet

1.ADM1485AQ.pdf (8 pages)

Current page: 1 of 8
Download datasheet (140Kb)

GENERAL DESCRIPTION

The ADM1485 is a differential line transceiver suitable for high

speed bidirectional data communication on multipoint bus

transmission lines. It is designed for balanced data transmission

and complies with both EIA Standards RS-485 and RS-422.

The part contains a differential line driver and a differential line

receiver. Both the driver and the receiver may be enabled inde-

pendently. When disabled, the outputs are tristated.

The ADM1485 operates from a single +5 V power supply.

Excessive power dissipation caused by bus contention or by

output shorting is prevented by a thermal shutdown circuit.

This feature forces the driver output into a high impedance state

if during fault conditions a significant temperature increase is

detected in the internal driver circuitry.

Up to 32 transceivers may be connected simultaneously on a

bus, but only one driver should be enabled at any time. It is

important therefore that the remaining disabled drivers do not

load the bus. To ensure this, the ADM1485 driver features high

output impedance when disabled and also when powered down.

This minimizes the loading effect when the transceiver is not

being utilized. The high impedance driver output is maintained

over the entire common-mode voltage range from –7 V to +12 V.

The receiver contains a fail safe feature which results in a logic

high output state if the inputs are unconnected (floating).

The ADM1485 is fabricated on BiCMOS, an advanced mixed

technology process combining low power CMOS with fast

switching bipolar technology. All inputs and outputs contain

protection against ESD; all driver outputs feature high source

and sink current capability. An epitaxial layer is used to guard

against latch-up.

The ADM1485 features extremely fast switching speeds. Mini-

mal driver propagation delays permit transmission at data rates

up to 30 Mbits/s while low skew minimizes EMI interference.

The part is fully specified over the commercial and industrial

temperature range and is available in an 8-lead DIL/SOIC

package.

FUNCTIONAL BLOCK DIAGRAM

EIA RS-485 Transceiver

ADM1485

8-Lead

+5 V Low Power

ADM1485

GND

Related parts for ADM1485AQ

ADM1485AQ Summary of contents

Page 1

GENERAL DESCRIPTION The ADM1485 is a differential line transceiver suitable for high speed bidirectional data communication on multipoint bus transmission lines designed for balanced data transmission and complies with both EIA Standards RS-485 and RS-422. The part ...

Page 2

ADM1485–SPECIFICATIONS Parameter DRIVER Differential Output Voltage OD3 ∆|V | for Complementary Output States OD Common-Mode Output Voltage V OC ∆|V | for Complementary Output States OD Output Short Circuit Current (V OUT Output Short Circuit Current (V ...

Page 3

... Z Z Model ADM1485JN ADM1485JR OUTPUT ADM1485AN RO ADM1485AR ADM1485AQ ADM1485 PIN FUNCTION DESCRIPTION Receiver Output. When enabled if A > 200 mV, then RO = High < 200 mV, then RO = Low. Receiver Output Enable. A low level enables the receiver output, RO. A high level places high impedance state ...

Page 4

ADM1485 Test Circuits OD3 A R LDIFF B Switching Characteristics 3V 1. PLH B 1/2VO SKEW VO 90% POINT 0V 10% POINT – 1. 2.3V A, ...

Page 5

OUTPUT VOLTAGE – Volts 0 8mA 0.3 0.2 0.1 –50 – 100 125 TEMPERATURE – C 100 90 ...

Page 6

ADM1485–Typical Performance Characteristics –50 – 100 125 TEMPERATURE – C 100 500mV 500mV 5ns D R 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0 –50 –25 25 ...

Page 7

APPLICATIONS INFORMATION Differential Data Transmission Differential data transmission is used to reliably transmit data at high rates over long distances and through noisy environments. Differential transmission nullifies the effects of ground shifts and noise signals which appear as common-mode voltages ...

Page 8

ADM1485 0.0098 (0.25) 0.0040 (0.10) OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 8-Lead SOIC (SO-8) 0.1968 (5.00) 0.1890 (4.80 0.2440 (6.20) 0.1574 (4.00) 0.2284 (5.80) 0.1497 (3.80 PIN 1 0.0500 (1.27) BSC 0.0688 (1.75) 0.0532 ...

Related keywords

ADM1485AQ datasheet
ADM1485AQ data sheet
ADM1485AQ pdf datasheet
ADM1485AQ component
ADM1485AQ part
ADM1485AQ distributor
ADM1485AQ RoHS
ADM1485AQ datasheet download