参数资料
型号: ADM489
厂商: Analog Devices, Inc.
英文描述: Full-Duplex, Low Power,Slew Rate Limited, EIA RS-486 Transceivers(低功耗,全双工,转换速率限制,RS-485收发器)
中文描述: 全双工,低功耗,限摆率限制,环境影响评估的RS - 486收发器(低功耗,全双工,转换速率限制,RS - 485接口收发器)
文件页数: 8/12页
文件大小: 179K
代理商: ADM489
ADM488/ADM489
–8–
REV. 0
GE NE RAL INFORMAT ION
T he ADM488/ADM489 is a ruggedized RS-485 transceiver that
operates from a single +5 V supply.
It contains protection against radiated and conducted interference.
It is ideally suited for operation in electrically harsh environ-
ments or where cables may be plugged/unplugged. It is also
immune to high RF field strengths without special shielding
precautions. It is intended for balanced data transmission and
complies with both EIA Standards RS-485 and RS-422. It con-
tains a differential line driver and a differential line receiver, and
is suitable for full duplex data transmission.
T he input impedance on the ADM488/ADM489 is 12 k
,
allowing up to 32 transceivers on the differential bus.
T he ADM488/ADM489 operates from a single +5 V
±
10%
power supply. Excessive power dissipation caused by bus con-
tention or by output shorting is prevented by a thermal shut-
down circuit. T his feature forces the driver output into a high
impedance state if, during fault conditions, a significant tem-
perature increase is detected in the internal driver circuitry.
T he receiver contains a fail-safe feature that results in a logic
high output state if the inputs are unconnected (floating).
A high level of robustness is achieved using internal protection
circuitry, eliminating the need for external protection compo-
nents such as tranzorbs or surge suppressors.
Low electromagnetic emissions are achieved using slew limited
drivers, minimizing interference both conducted and radiated.
T he ADM488/ADM489 can transmit at data rates up to
250 kbps.
A typical application for the ADM488/ADM489 is illustrated in
Figure 19. T his shows a full-duplex link where data may be
transferred at rates up to 250 kbps. A terminating resistor is
shown at both ends of the link. T his termination is not critical
since the slew rate is controlled by the ADM488/ADM489 and
reflections are minimized.
T he communications network may be extended to include
multipoint connections as shown in Figure 25. Up to 32 trans-
ceivers may be connected to the bus.
T ables I and II show the truth tables for transmitting and
receiving.
T able I. T ransmitting T ruth T able
Inputs
DE
Outputs
RE
DI
Z
Y
X
X
0
1
1
1
0
0
1
0
X
X
0
1
Hi-Z
Hi-Z
1
0
Hi-Z
Hi-Z
X = Don’t Care.
T able II. Receiving T ruth T able
Inputs
DE
Output
RO
RE
A-B
+0.2 V
+0.2 V
Inputs O/C
X
0
0
0
1
0
1
0
0
1
0
1
Hi-Z
X = Don’t Care.
E FT T RANSIE NT PROT E CT ION SCHE ME
T he ADM488/ADM489 uses protective clamping structures on
its inputs and outputs that clamp the voltage to a safe level and
dissipates the energy present in ESD (Electrostatic) and EFT
(Electrical Fast T ransients) discharges.
FAST T RANSIE NT BURST IMMUNIT Y (IE C1000-4-4)
IEC1000-4-4 (previously 801-4) covers electrical fast-transient/
burst (EFT ) immunity. Electrical fast transients occur as a
result of arcing contacts in switches and relays. T he tests simu-
late the interference generated when, for example, a power relay
disconnects an inductive load. A spark is generated due to the
well known back EMF effect. In fact, the spark consists of a
burst of sparks as the relay contacts separate. T he voltage ap-
pearing on the line, therefore, consists of a burst of extremely
fast transient impulses. A similar effect occurs when switching
on fluorescent lights.
ADM488
D
RO
DI
A
B
Z
Y
RE
DE
+5V
0.1
m
F
RS-485/RS-422 LINK
R
R
ADM489
+5V
0.1
m
F
D
RO
DI
RE
DE
GND
GND
V
CC
V
CC
A
B
Z
Y
Figure 19. ADM488/ADM489 Full-Duplex Data Link
相关PDF资料
PDF描述
ADM560JR Ultralow Power, +3.3 V, RS-232 Notebook PC Serial Port Drivers/Receivers
ADM560JRS Ultralow Power, +3.3 V, RS-232 Notebook PC Serial Port Drivers/Receivers
ADM561 Ultralow Power, +3.3 V, RS-232 Notebook PC Serial Port Drivers/Receivers
ADM561JR Ultralow Power, +3.3 V, RS-232 Notebook PC Serial Port Drivers/Receivers
ADM561JRS Ultralow Power, +3.3 V, RS-232 Notebook PC Serial Port Drivers/Receivers
相关代理商/技术参数
参数描述
ADM489A 制造商:AD 制造商全称:Analog Devices 功能描述:Full-Duplex, Low Power, Slew Rate Limited, EIA RS-485 Transceivers
ADM489ABRMZ 功能描述:IC TXRX RS485/422 DIFF 10MSOP RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器,接收器,收发器 系列:- 标准包装:121 系列:- 类型:收发器 驱动器/接收器数:1/1 规程:RS422,RS485 电源电压:3 V ~ 3.6 V 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-DFN(3x3) 包装:管件
ADM489ABRMZ-REEL7 功能描述:IC TXRX RS485/422 DIFF 10MSOP RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器,接收器,收发器 系列:- 标准包装:121 系列:- 类型:收发器 驱动器/接收器数:1/1 规程:RS422,RS485 电源电压:3 V ~ 3.6 V 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-DFN(3x3) 包装:管件
ADM489ABRZ 功能描述:IC TXRX RS485/422 DIFF 14SOIC RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器,接收器,收发器 系列:- 标准包装:121 系列:- 类型:收发器 驱动器/接收器数:1/1 规程:RS422,RS485 电源电压:3 V ~ 3.6 V 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-DFN(3x3) 包装:管件
ADM489ABRZ-REEL7 功能描述:IC TXRX RS485/422 DIFF 14SOIC RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器,接收器,收发器 系列:- 标准包装:121 系列:- 类型:收发器 驱动器/接收器数:1/1 规程:RS422,RS485 电源电压:3 V ~ 3.6 V 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-DFN(3x3) 包装:管件