- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄10804 > ADM489ARZ (Analog Devices Inc)IC TX/RX RS485 LO-SLEW/EN 14SOIC PDF資料下載
參數(shù)資料
| 型號： | ADM489ARZ |
| 廠商： | Analog Devices Inc |
| 文件頁數(shù)： | 3/16頁 |
| 文件大小： | 0K |
| 描述： | IC TX/RX RS485 LO-SLEW/EN 14SOIC |
| 標(biāo)準(zhǔn)包裝： | 56 |
| 類型： | 收發(fā)器 |
| 驅(qū)動(dòng)器/接收器數(shù)： | 1/1 |
| 規(guī)程： | RS422，RS485 |
| 電源電壓： | 4.5 V ~ 5.5 V |
| 安裝類型： | 表面貼裝 |
| 封裝/外殼： | 14-SOIC（0.154"，3.90mm 寬） |
| 供應(yīng)商設(shè)備封裝： | 14-SOICN |
| 包裝： | 管件 |
| 產(chǎn)品目錄頁面： | 790 (CN2011-ZH PDF) |
ADM488/ADM489
Rev. D | Page 11 of 16
THEORY OF OPERATION
The ADM488/ADM489 are ruggedized RS-485 transceivers
that operate from a single 5 V supply. They contain protection
against radiated and conducted interference and are ideally
suited for operation in electrically harsh environments or where
cables can be plugged/unplugged. They are also immune to
high RF field strengths without special shielding precautions.
They are intended for balanced data transmission and comply
with both EIA RS-485 and RS-422 standards. They contain a
differential line driver and a differential line receiver, and are
suitable for full-duplex data transmission.
The input impedance on the ADM488/ADM489 is 12 kΩ,
allowing up to 32 transceivers on the differential bus. The
ADM488/ADM489 operate from a single 5 V ± 10% power
supply. A thermal shutdown circuit prevents excessive power
dissipation caused by bus contention 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). A
high level of robustness is achieved using internal protection
circuitry, eliminating the need for external protection com-
ponents such as tranzorbs or surge suppressors. Furthermore,
low electromagnetic emissions are achieved using slew limited
drivers, minimizing interference both conducted and radiated.
The ADM488/ADM489 can transmit at data rates up to
250 kbps. A typical application for the ADM488/ADM489 is
illustrated in Figure 24 showing a full-duplex link where data is
transferred at rates of up to 250 kbps. A terminating resistor is
shown at both ends of the link. This termination is not critical
because the slew rate is controlled by the ADM488/ADM489
and reflections are minimized.
ADM488
D
RO
DI
A
B
Z
Y
DE
5V
0.1F
RS-485/RS-422 LINK
R
ADM489
5V
0.1F
D
RO
DI
DE
GND
VCC
A
B
Z
Y
RE
000
79
-0
24
Figure 24. ADM488/ADM489 Full-Duplex Data Link
The communications network can be extended to include
multipoint connections, as shown in Figure 30. As many as
32 transceivers can be connected to the bus.
Table 6 and Table 7 show the truth tables for transmitting and
receiving.
Table 6. Transmitting Truth Table
Inputs
Outputs
RE
DE
DI
Z
Y
1
0
1
1
0
1
0
Hi-Z
1
0
Hi-Z
1 X = Don’t care.
Table 7. Receiving Truth Table
Inputs
Output
RE
DE
A to B
RO
0
≥ +0.2 V
1
0
≤
0.2 V
0
Inputs O/C
1
0
Hi-Z
1 X = Don’t care.
EFT TRANSIENT PROTECTION SCHEME
The ADM488/ADM489 use protective clamping structures on
their inputs and outputs that clamp the voltage to a safe level
and dissipate the energy present in ESD (electrostatic) and EFT
(electrical fast transients) discharges.
FAST TRANSIENT BURST IMMUNITY (IEC1000-4-4)
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. The tests simulate 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. The voltage appearing on the line,
therefore, consists of a burst of extremely fast transient impulses.
A similar effect occurs when switching on fluorescent lights.
The fast transient burst test, defined in IEC1000-4-4, simulates
this arcing, and its waveform is illustrated in Figure 25. It
consists of a burst of 2.5 kHz to 5 kHz transients repeating at
300 ms intervals. It is specified for both power and data lines.
Four severity levels are defined in terms of an open-circuit voltage
as a function of installation environment. The installation
environments are defined as
Well protected
Protected
Typical industrial
Severe industrial
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| VE-BNT-MX-F4 | CONVERTER MOD DC/DC 6.5V 75W |
| VE-J73-MY-S | CONVERTER MOD DC/DC 24V 50W |
| VE-BNT-MX-F3 | CONVERTER MOD DC/DC 6.5V 75W |
| VE-J72-MY-S | CONVERTER MOD DC/DC 15V 50W |
| VE-BNT-MX-F1 | CONVERTER MOD DC/DC 6.5V 75W |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ADM489ARZ | 制造商:Analog Devices 功能描述:RS-485 IC |
| ADM489ARZ-REEL | 功能描述:IC TXRX RS-485 DIFF LP 14SOIC RoHS:是 類別:集成電路 (IC) >> 接口 - 驅(qū)動(dòng)器，接收器，收發(fā)器 系列:- 標(biāo)準(zhǔn)包裝:121 系列:- 類型:收發(fā)器 驅(qū)動(dòng)器/接收器數(shù):1/1 規(guī)程:RS422，RS485 電源電壓:3 V ~ 3.6 V 安裝類型:表面貼裝 封裝/外殼:10-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:10-DFN（3x3） 包裝:管件 |
| ADM489ARZ-REEL7 | 功能描述:IC TXRX RS-485 DIFF LP 14SOIC RoHS:是 類別:集成電路 (IC) >> 接口 - 驅(qū)動(dòng)器，接收器，收發(fā)器 系列:- 標(biāo)準(zhǔn)包裝:121 系列:- 類型:收發(fā)器 驅(qū)動(dòng)器/接收器數(shù):1/1 規(guī)程:RS422，RS485 電源電壓:3 V ~ 3.6 V 安裝類型:表面貼裝 封裝/外殼:10-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:10-DFN（3x3） 包裝:管件 |
| ADM51 | 功能描述:電路內(nèi)置調(diào)試器 In-Circuit Debugger w/Chameleon RoHS:否 制造商:Microchip Technology 產(chǎn)品:In-Circuit Debugger Kits 工具用于評估:PIC MCUs, dsPIC DSCs 用于:07-00024, AC164113 核心:dsPIC, PIC 接口類型:USB 工作電源電壓:3 V to 5 V |
| ADM-51 | 制造商:TDK 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。