|
|
PDF ADM485 Data sheet ( Hoja de datos )
| Número de pieza | ADM485 | |
| Descripción | 5V Low Power EIA RS-485 Transceiver | |
| Fabricantes | Analog Devices | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de ADM485 (archivo pdf) en la parte inferior de esta página. Total 16 Páginas | ||
|
No Preview Available !
FEATURES
Meets EIA RS-485 standard
5 Mbps data rate
Single 5 V supply
–7 V to +12 V bus common-mode range
High speed, low power BiCMOS
Thermal shutdown protection
Short-circuit protection
Driver propagation delay: 10 ns typical
Receiver propagation delay: 15 ns typical
High-Z outputs with power off
Superior upgrade for LTC485
APPLICATIONS
Low power RS-485 systems
DTE/DCE interface
Packet switching
Local area networks (LNAs)
Data concentration
Data multiplexers
Integrated services digital network (ISDN)
GENERAL DESCRIPTION
The ADM485 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 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 can be enabled independently.
When disabled, the outputs are three-stated.
The ADM485 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. If
during fault conditions, a significant temperature increase is
detected in the internal driver circuitry, this feature forces the
driver output into a high impedance state.
Up to 32 transceivers can 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 ADM485 driver features high
output impedance when disabled and when powered down,
which minimizes the loading effect when the transceiver is not
being used. The high impedance driver output is maintained
over the common-mode voltage range of −7 V to +12 V.
Rev. F
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.
5 V Low Power
EIA RS-485 Transceiver
ADM485
FUNCTIONAL BLOCK DIAGRAM
ADM485
RO 1
RE 2
R
8 VCC
7B
DE 3
DI 4
D
6A
5 GND
Figure 1.
The receiver contains a fail-safe feature that results in a logic
high output state if the inputs are unconnected (floating).
The ADM485 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 ADM485 features extremely fast switching speeds. Minimal
driver propagation delays permit transmission at data rates up
to 5 Mbps while low skew minimizes EMI interference.
The part is fully specified over the commercial and industrial
temperature range and is available in 8-lead PDIP, 8-lead SOIC,
and small footprint, 8-lead MSOP packages.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113 ©1993–2008 Analog Devices, Inc. All rights reserved.
1 page  
ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted.
Table 3.
Parameter
VCC
Inputs
Driver Input (DI)
Control Inputs (DE, RE)
Receiver Inputs (A, B)
Outputs
Driver Outputs (A, B)
Receiver Output
Power Dissipation 8-Lead MSOP
θJA, Thermal Impedance
Power Dissipation 8-Lead PDIP
θJA, Thermal Impedance
Power Dissipation 8-Lead SOIC
θJA, Thermal Impedance
Operating Temperature Range
Commercial Range (J Version)
Industrial Range (A Version)
Storage Temperature Range
Lead Temperature (Soldering, 10 sec)
Vapor Phase (60 sec)
Infrared (15 sec)
Rating
−0.3 V to +7 V
−0.3 V to VCC + 0.3 V
−0.3 V to VCC + 0.3 V
−9 V to +14 V
−9 V to +14 V
−0.5 V to VCC + 0.5 V
900 mW
206°C/W
500 mW
130°C/W
450 mW
170°C/W
0°C to 70°C
−40°C to +85°C
−65°C to +150°C
300°C
215°C
220°C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ADM485
Table 4. Transmitting
Inputs
DE DI
11
10
0 X1
1 X = don’t care.
2 Z = high impedance.
Table 5. Receiving
RE Input A − Input B
0 ≥ +0.2 V
0 ≤ −0.2 V
0 Inputs open
1 X1
1 X = don’t care.
2 Z = high impedance.
ESD CAUTION
Outputs
BA
01
10
Z2 Z2
Output RO
1
0
1
Z2
Rev. F | Page 5 of 16
5 Page 
SWITCHING CHARACTERISTICS
3V
1.5V
1.5V
0V
B
1/2VO
VO
tPLH
tPHL
A
+VO 90% POINT
0V
10% POINT
–VO tR
tSKEW = tPLH – tPHL
90% POINT
10% POINT
tF
Figure 26. Driver Propagation Delay, Rise/Fall Timing
DE 1.5V
tZL
1.5V
tLZ
3V
0V
A, B
A, B
2.3V
tZH
2.3V
VOL + 0.5V
tHZ
VOH – 0.5V
VOL
VOH
0V
Figure 27. Driver Enable/Disable Timing
ADM485
A, B
RO
RE
RO
RO
0V
0V 0V
tPLH
tPHL
1.5V
tSKEW = tPLH – tPHL
1.5V
Figure 28. Receiver Propagation Delay
VOH
VOL
1.5V
tZL
1.5V
tLZ
3V
0V
1.5V
OUTPUT LOW
VOL + 0.5V
VOL
tZH tHZ
OUTPUT HIGH
1.5V
VOH
VOH – 0.5V
Figure 29. Receiver Enable/Disable Timing
Rev. F | Page 11 of 16
11 Page | ||
| Páginas | Total 16 Páginas | |
| PDF Descargar | [ Datasheet ADM485.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| ADM483 | Slew-Rate Limited RS-485/RS-422 Transceiver | Analog Devices |
| ADM483E | +-15 kV ESD Protected/ EMC Compliant Slew Rate Limited/ EIA RS-485 Transceiver | Analog Devices |
| ADM485 | 5V Low Power EIA RS-485 Transceiver | Analog Devices |
| ADM4850 | Half-Duplex and Full-Duplex RS-485/RS-422 Transceivers | Analog Devices |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |