參數(shù)資料
型號: LTC488
廠商: Linear Technology Corporation
英文描述: Quad RS485 Line Receiver
中文描述: 485四線接收器
文件頁數(shù): 6/12頁
文件大?。?/td> 228K
代理商: LTC488
6
LTC488/LTC489
TI
W
E WAVEFOR
S
UG
WITCHI
W
S
Figure 3. Receiver Propagation Delays
0V
–V
OD2
t
PHL
f = 1MHz; t
r
10ns; t
f
10ns
0V
t
PLH
V
OD2
INPUT
A, B
V
OH
1.5V
1.5V
V
OL
RO
INPUT
488/9 F03
f = 1MHz; t
r
10ns; t
f
10ns
1.5V
RO
488/9 F04
0V
3V
1.5V
t
ZL
V
OL
V
OH
1.5V
t
LZ
0.5V
0.5V
t
HZ
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
0V
5V
1.5V
t
ZH
RO
EN OR
EN12
Figure 4. Receiver Enable and Disable Times
U
S
A
O
PPLICATI
U
U
Typical Application
A typical connection of the LTC488/LTC489 is shown in
Figure 5. Two twisted-pair wires connect up to 32 driver/
receiver pairs for half-duplex data transmission. There are
no restrictions on where the chips are connected to the
wires, and it isn’t necessary to have the chips connected
at the ends. However, the wires must be terminated only
at the ends with a resistor equal to their characteristic
impedance, typically 120
. The input impedance of a
receiver is typically 20k to GND, or 0.5 unit RS485 load, so
in practice 50 to 60 transceivers can be connected to the
same wires. The optional shields around the twisted-pair
help reduce unwanted noise, and are connected to GND at
one end.
Cables and Data Rate
The transmission line of choice for RS485 applications is
a twisted-pair. There are coaxial cables (twinaxial) made
for this purpose that contain straight-pairs, but these are
less flexible, more bulky, and more costly than twisted-
pairs. Many cable manufacturers offer a broad range of
120
cables designed for RS485 applications.
Losses in a transmission line are a complex combination
of DC conductor loss, AC losses (skin effect), leakage, and
AC losses in the dielectric. In good polyethylene cable
such as the Belden 9841, the conductor losses and dielec-
tric losses are of the same order of magnitude, leading to
relatively low overall loss (Figure 6).
相關(guān)PDF資料
PDF描述
LTC488C Quad RS485 Line Receiver
LTC488CN Quad RS485 Line Receiver
LTC488CS Quad RS485 Line Receiver
LTC488I Quad RS485 Line Receiver
LTC488IN Quad RS485 Line Receiver
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC488CN 功能描述:IC LINE RCVR RS485 QUAD 16-DIP RoHS:否 類別:集成電路 (IC) >> 接口 - 驅(qū)動器,接收器,收發(fā)器 系列:- 標(biāo)準(zhǔn)包裝:27 系列:- 類型:收發(fā)器 驅(qū)動器/接收器數(shù):3/3 規(guī)程:RS232,RS485 電源電壓:4.75 V ~ 5.25 V 安裝類型:表面貼裝 封裝/外殼:28-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:28-SOIC 包裝:管件
LTC488CN#PBF 功能描述:IC LINE RCVR RS485 QUAD 16-DIP RoHS:是 類別:集成電路 (IC) >> 接口 - 驅(qū)動器,接收器,收發(fā)器 系列:- 產(chǎn)品培訓(xùn)模塊:RS-232 & USB Transceiver 標(biāo)準(zhǔn)包裝:2,000 系列:- 類型:收發(fā)器 驅(qū)動器/接收器數(shù):1/1 規(guī)程:RS232 電源電壓:3 V ~ 5.5 V 安裝類型:表面貼裝 封裝/外殼:16-SSOP(0.209",5.30mm 寬) 供應(yīng)商設(shè)備封裝:16-SSOP 包裝:帶卷 (TR) 其它名稱:296-19849-2
LTC488CNPBF 制造商:Linear Technology 功能描述:LTC488CNPBF
LTC488CS 制造商:Linear Technology 功能描述:Quad RS485 Line Receiver
LTC488CSW 功能描述:IC LINE RCVR RS485 QUAD 16-SOIC RoHS:否 類別:集成電路 (IC) >> 接口 - 驅(qū)動器,接收器,收發(fā)器 系列:- 標(biāo)準(zhǔn)包裝:27 系列:- 類型:收發(fā)器 驅(qū)動器/接收器數(shù):3/3 規(guī)程:RS232,RS485 電源電壓:4.75 V ~ 5.25 V 安裝類型:表面貼裝 封裝/外殼:28-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:28-SOIC 包裝:管件