数据搜索系统,热门电子元器件搜索
  Chinese  ▼
ALLDATASHEETCN.COM

X  

ADM1491E 数据表(PDF) 10 Page - Analog Devices

部件名 ADM1491E
功能描述  16 Mbps, ESD Protected, Full-Duplex RS-485 Transceivers
Download  16 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
制造商  AD [Analog Devices]
网页  http://www.analog.com
标志 AD - Analog Devices

ADM1491E 数据表(HTML) 10 Page - Analog Devices

Back Button ADM1491E Datasheet HTML 6Page - Analog Devices ADM1491E Datasheet HTML 7Page - Analog Devices ADM1491E Datasheet HTML 8Page - Analog Devices ADM1491E Datasheet HTML 9Page - Analog Devices ADM1491E Datasheet HTML 10Page - Analog Devices ADM1491E Datasheet HTML 11Page - Analog Devices ADM1491E Datasheet HTML 12Page - Analog Devices ADM1491E Datasheet HTML 13Page - Analog Devices ADM1491E Datasheet HTML 14Page - Analog Devices Next Button
Zoom Inzoom in Zoom Outzoom out
 10 / 16 page
background image
ADM1491E
Rev. 0 | Page 10 of 16
THEORY OF OPERATION
The ADM1491E is an RS-485 transceiver that operates from a
single 5 V ± 5% power supply. The ADM1491E is intended for
balanced data transmission and complies with both TIA/EIA-485-A
and TIA/EIA-422-B. It contains a differential line driver and a
differential line receiver and is suitable for full-duplex data
transmission.
The input impedance of the ADM1491E is 12 kΩ, allowing up
to 32 transceivers on the differential bus. A thermal shutdown
circuit prevents excessive power dissipation caused by bus con-
tention or by output shorting. 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.
The receiver contains a fail-safe feature that results in a logic
high output state if the inputs are unconnected (floating).
The ADM1491E features very low propagation delay, ensuring
maximum baud rate operation. The balanced driver ensures
distortion free transmission.
Another important specification is a measure of the skew
between the complementary outputs. Excessive skew impairs
the noise immunity of the system and increases the amount
of electromagnetic interference (EMI).
TRUTH TABLES
Table 6. Truth Table Abbreviations
Letter
Description
H
High level
I
Indeterminate
L
Low level
X
Irrelevant
Z
High impedance (off )
Table 7. Transmitting
Inputs
Outputs
DE
DI
Z
Y
H
H
L
H
H
L
H
L
L
X
Z
Z
Table 8. Receiving
Inputs
Output
RE
A − B
RO
L
≥ +0.2 V
H
L
≤ −0.2 V
L
L
−0.2 V ≤ A − B ≤ +0.2 V
I
L
Inputs open
H
H
X
Z
ESD TRANSIENT PROTECTION SCHEME
The ADM1491E uses protective clamping structures on its
inputs and outputs to clamp the voltage to a safe level and
dissipate the energy present in ESD (electrostatic). The
protection structure achieves ESD protection up to ±8 kV
human body model (HBM).
ESD Testing
Two coupling methods are used for ESD testing: contact dis-
charge and air gap discharge. Contact discharge calls for a direct
connection to the unit being tested; air gap discharge uses a higher
test voltage but does not make direct contact with the unit under
test. With air discharge, the discharge gun is moved toward the
unit under test, developing an arc across the air gap; hence the
term air discharge. This method is influenced by humidity, tem-
perature, barometric pressure, distance, and rate of closure of
the discharge gun. The contact discharge method, though less
realistic, is more repeatable and is gaining acceptance and
preference over the air gap method.
Although very little energy is contained within an ESD pulse,
the extremely fast rise time, coupled with high voltages, can cause
failures in unprotected semiconductors. Catastrophic destruction
can occur immediately because of arcing or heating. Even if cata-
strophic failure does not occur immediately, the device can suffer
from parametric degradation, resulting in degraded performance.
The cumulative effects of continuous exposure can eventually
lead to complete failure.
C1
R2
HIGH
VOLTAGE
GENERATOR
DEVICE
UNDER TEST
NOTES
1. THE ESD TEST METHOD USED IS THE
HUMAN BODY MODEL (±8kV) WITH
R2 = 1500
Ω AND C1 = 100pF.
Figure 25. ESD Generator
I/O lines are particularly vulnerable to ESD damage. Simply
touching or plugging in an I/O cable can result in a static dis-
charge that can damage or destroy the interface product connected
to the I/O port. It is, therefore, extremely important to have high
levels of ESD protection on the I/O lines.
The ESD discharge can induce latch-up in the device under test.
Therefore, it is important to conduct ESD testing on the I/O pins
while device power is applied. This type of testing is more repre-
sentative of a real-world I/O discharge where the equipment is
operating normally when the discharge occurs.


类似零件编号 - ADM1491E

制造商部件名数据表功能描述
logo
Analog Devices
ADM1491E AD-ADM1491E Datasheet
346Kb / 16P
   16 Mbps, ESD Protected, Full-Duplex RS-485 Transceivers
Rev. D
ADM1491EBRMZ AD-ADM1491EBRMZ Datasheet
341Kb / 16P
   16 Mbps, ESD Protected, Full-Duplex RS-485 Transceivers
REV. B
ADM1491EBRMZ AD-ADM1491EBRMZ Datasheet
346Kb / 16P
   16 Mbps, ESD Protected, Full-Duplex RS-485 Transceivers
Rev. D
ADM1491EBRMZ-REEL7 AD-ADM1491EBRMZ-REEL7 Datasheet
341Kb / 16P
   16 Mbps, ESD Protected, Full-Duplex RS-485 Transceivers
REV. B
ADM1491EBRMZ-REEL7 AD-ADM1491EBRMZ-REEL7 Datasheet
346Kb / 16P
   16 Mbps, ESD Protected, Full-Duplex RS-485 Transceivers
Rev. D
More results

类似说明 - ADM1491E

制造商部件名数据表功能描述
logo
Analog Devices
ADM1490E AD-ADM1490E_V01 Datasheet
346Kb / 16P
   16 Mbps, ESD Protected, Full-Duplex RS-485 Transceivers
Rev. D
ADM1490E AD-ADM1490E Datasheet
341Kb / 16P
   16 Mbps, ESD Protected, Full-Duplex RS-485 Transceivers
REV. B
logo
Sipex Corporation
SP1490E SIPEX-SP1490E_05 Datasheet
149Kb / 10P
   Full Duplex RS-485 Transceivers
logo
Exar Corporation
SP490 EXAR-SP490 Datasheet
552Kb / 12P
   Full Duplex RS-485 Transceivers
logo
Sipex Corporation
SP1490E SIPEX-SP1490E Datasheet
73Kb / 10P
   Full Duplex RS-485 Transceivers
SP490 SIPEX-SP490 Datasheet
83Kb / 12P
   Full Duplex RS-485 Transceivers
SP490 SIPEX-SP490 Datasheet
94Kb / 10P
   Full Duplex RS-485 Transceivers
logo
Exar Corporation
SP491CN-L EXAR-SP491CN-L Datasheet
453Kb / 11P
   Full Duplex RS-485 Transceivers
logo
Sipex Corporation
SP490 SIPEX-SP490_05 Datasheet
161Kb / 12P
   Full Duplex RS-485 Transceivers
logo
Maxim Integrated Produc...
MAX14784E MAXIM-MAX14784E Datasheet
846Kb / 17P
   Full-Duplex, 짹35kV ESD-Protected, RS-485 Transceivers for High-Speed Communication
19-6863; Rev 2; 1/15
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16


数据表 下载

Go To PDF Page


链接网址




隐私政策
ALLDATASHEETCN.COM
ALLDATASHEET是否为您带来帮助?  [ DONATE ] 

关于 Alldatasheet   |   广告服务   |   联系我们   |   隐私政策   |   链接交换   |   制造商名单
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com