參數(shù)資料
型號(hào): SP485ECN
英文描述: Enhanced Low Power Half-Duplex RS-485 Transceivers
中文描述: 增強(qiáng)型低功耗半雙工RS - 485收發(fā)器
文件頁數(shù): 6/9頁
文件大?。?/td> 74K
代理商: SP485ECN
Date: 6/21/04
SP485R RS-485 Serial Transceiver
6
Copyright 2004 Sipex Corporation
with the two 125
cable termination resistors
on each end.
The receiver contains a enable pin (RE) which
enables the receiver when a logic LOW is
asserted. A logic HIGH will tri-state the
receiver output and the inputs will maintain
at least 120k
impedance. The receiver can
operate to at least 1Mbps.
The receiver also contains a fail-safe feature
which outputs a logic HIGH when the inputs are
open as in a disconnected cable.
SHUTDOWN MODE
The
SP481R
includes a shutdown function to
reduce power consumption. The shutdown is
activated by simultaneously applying a logic
LOW to DE and a logic HIGH to RE. While in
the shutdown mode, the power supply current is
typically less than 1
μ
A. The driver outputs are
disabled and are at a high impedance state
determined by the receiver input impedance
which should be at least 120k
. The receiver
output is at also at high impedance during
shutdow. Output leakage current when the
receiver is disabled is under 1
μ
A.
GENERAL DESCRIPTION
The
SP485R
is a low power RS-485 differential
transceiver. Similar to the SP485, the
SP485R
contains a half-duplex driver and receiver with
tri-state control. However, the SP485R is in-
tended for increased connections on a single bus
compared to the orignal RS-485 specification.
The RS-485 standard is ideal for multi-drop
applications where one bus can contain many
drivers and/or receivers. The RS-485 standard
implementation allows up to 32 transceivers to
be connected on to the data bus. RS-485 is also
specified for driving higher speeds over long
cable lengths of up to 4,000 feet. The SP485R
and SP481R exceed the standard b allowing up
to 400 receivers to share a bus.
DRIVERS
The driver output complies with the RS-485
electrical characteristics as specified by the
standard. The output swings from 0V to V
CC
and
maintains greater than +1.5V with a 54
load
attached between the two outputs. In adhering
to the RS-485 specification, the driver outputs
inherently comply with the RS-422 standard.
With a load of 100
between the two outputs,
the driver can sustain at least +2.0V.
The driver contains an enable pin (DE) which
tri-states the output when DE is a logic LOW.
The outputs
during the tri-stated condition are
at a high impedance (>100k
). A logic HIGH
enables the driver for normal operation. The
driver can operate to at least 5Mbps
.
RECEIVERS
The
SP485R
receiver has differential inputs
with an input sensitivity of lower than
±
200mV.
As mentioned above, the RS-485 specification
allows up to 32 transceivers on a the same bus.
The
SP485R
allows over 400 transceivers on
the same bus due to the high input impedance of
at least 120k
. This higher capacity allows
more components to be attached to the same
bus without degrading the signal quality. The
drivers are still able to drive an equivalent 54
from the 320 transceivers with an input
impedance of at least 120k
in parallel along
相關(guān)PDF資料
PDF描述
SP485ECP Enhanced Low Power Half-Duplex RS-485 Transceivers
SP485EEN Enhanced Low Power Half-Duplex RS-485 Transceivers
SP485EEP Enhanced Low Power Half-Duplex RS-485 Transceivers
SP485EN Low Power Half-Duplex RS-485 Transceivers
SP485ES Low Power Half-Duplex RS-485 Transceivers
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SP485ECN-L 功能描述:RS-485接口IC RS485 10000 kbps EMI temp 0C to 70C RoHS:否 制造商:Texas Instruments 數(shù)據(jù)速率:250 Kbps 工作電源電壓:3.3 V 電源電流:750 uA 工作溫度范圍:- 40 C to + 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Tube
SP485ECN-L/TR 功能描述:RS-485接口IC Low Pwr Half-Duplex RS-485 RoHS:否 制造商:Texas Instruments 數(shù)據(jù)速率:250 Kbps 工作電源電壓:3.3 V 電源電流:750 uA 工作溫度范圍:- 40 C to + 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Tube
SP485ECP 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Enhanced Low Power Half-Duplex RS-485 Transceivers
SP485ECP-L 功能描述:RS-485接口IC RS485 10000 kbps temp 0C to 70C RoHS:否 制造商:Texas Instruments 數(shù)據(jù)速率:250 Kbps 工作電源電壓:3.3 V 電源電流:750 uA 工作溫度范圍:- 40 C to + 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Tube
SP485EEN 制造商:Exar 功能描述:Enhanced Low Power Half-Duplex RS-485 Transceivers 制造商:Other 功能描述:Enhanced Low Power Half-Duplex RS-485 Transceivers