參數(shù)資料
型號： SP508
英文描述： Rugged 40Mbps, 8 Channel Multiprotocol Transceiver with Programmable DCE/DTE and Termination Resistors(40Mbps差分傳輸速率，8通道多協(xié)議收發(fā)器（帶可編程DCE/DTE和終端電阻器）)
中文描述： 堅固40Mbps的，8通道多協(xié)議收發(fā)器，具有可編程DCE的/ DTE和終端電阻（40Mbps的差分傳輸速率，8通道多協(xié)議收發(fā)器（帶可編程DCE的/ DTE的和終端電阻器））
文件頁數(shù)： 21/27頁
文件大小： 246K
代理商： SP508
21
rev. 8/31/00
SP508 Enhanced WAN Multi–Mode Serial Transceiver
Copyright 2000 Sipex Corporation
P
The fourth type of drivers are V.35 differential
drivers.
There are only three available on the
SP550 for data and clock (TxD, TxCE, and TxC
in DCE mode). These drivers are current sources
that drive loop current through a differential pair
resulting in a 550mV differential voltage at the
receiver. These drivers also incorporate fixed
termination networks for each driver in order to
set the V
and V
depending on load conditions.
This termination network is basically a “Y”
configuration consisting of two 51
resistors
connected in series and a 124
resistor connected
between the two 50
resistors and a V35TGND
output. Each of the three drivers and its associated
termination will have its own V35TGND output
for grounding convenience. Filtering can be done
on these pins to reduce common mode noise
transmitted over the transmission line by
connecting a capacitor to ground.
The drivers also have separate enable pins
which simplifies half-duplex configurations for
some applications, especially programmable
DTE/DCE. The enable pins will either enable or
disable the output of the drivers according to the
appropriate active logic illustrated on
Figure 45
.
The enable pins have internal pull-up and pull-
down devices, depending on the active polarity
of the receiver, that enable the driver upon power
if the enable lines are left floating. During disabled
conditions, the driver outputs will be at a high
impedance 3-state.
The driver inputs are both TTL or CMOS
compatible. All driver inputs have an internal
pull-up resistor so that the output will be at a
defined state at logic LOW (“0”). Unused driver
inputs can be left floating. The internal pull-up
resistor value is approximately 500k
.
Receivers
The
SP508
has eight enhanced independent
receivers. Control for the mode selection is done
via a three-bit control word that is the same as the
driver control word. Therefore, the modes for
the drivers and receivers are identical in the
application.
Like the drivers, the receivers are prearranged
for the specific requirements of the synchronous
serial interface. As the operating mode of the
receivers is changed, the electrical characteristics
will change to support the required serial interface
protocols of the receivers.
Table 1
shows
the mode of each receiver in the different
interface modes that can be selected. There are
two basic types of receiver circuits—ITU-T-V .28
(RS-232) and ITU-T-V.11, (RS-422).
The RS-232 (V.28) receiver is single-ended and
accepts RS-232 signals from the RS-232 driver.
The RS-232 receiver has an operating voltage
range of +15V and can receive signals downs to
+3V. The input sensitivity complies with
RS-232 and V .28 at +3V. The input impedance
is 3
to 7K
in accordance to RS-232 and V .28.
The receiver output produces a TTL/CMOS
signal with a +2.4V minimum for a logic “1” and
a +0.8V maximum for a logic “0”. The RS-232
(V.28) protocol uses these receivers for all data,
clock and control signals. They are also used in
V.35 mode for control line signals:
CTS, DSR, LL, and RL. The RS-232 receivers
can operate over 120kbps.
The second type of receiver is a differential type
that can be configured internally to support
ITU-T-V.10 and CCITT-V.35 depending on its
input conditions. This receiver has a typical
input impedance of 10k
and a differential
threshold of less than +100mV, which complies
with the ITU-T-V.11 (RS-422) specifications.
V.11 receivers are used in RS-449/V.36,
EIA-530, EIA-530A and X.21 as Category I
signals for receiving clock, data, and some control
line signals not covered by Category II V.10
circuits. The differential V.11 transceiver has
improved architecture that allows over 40Mbps
transmission rates.
For receivers dedicated for data and clock (RxD,
RxC, TxC) incorporate internal termination for
V.11. The termination resistor is typically 120
connected between the A and B inputs. The
termination is essential for minimizing crosstalk
and signal reflection over the transmission line .
The minimum value is guaranteed to exceed
100
, thus complying with the V.11 and RS-422
specifications. This resistor is invoked when the
receiver is operating as a V.11 receiver, in modes
EIA-530, EIA-530A, RS-449/V.36, and X.21.
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SP508/1.2/BLACK 制造商:Farnell / Pro-Power 功能描述:HEATSHRINK 50.8MM BLACK 1.2M 制造商:pro-power 功能描述:HEATSHRINK, 50.8MM, BLACK, 1.2M 制造商:pro-power 功能描述:HEAT SHRINK TUBING, 50.8MM ID, PO, BLK, 3.94FT; I.D. Supplied - Metric:50.8mm; I.D. Supplied - Imperial:2"; I.D. Recovered Max - Metric:25.4mm; I.D. Recovered Max - Imperial:1"; Shrink Ratio:2:1; Shrink Tubing / Boot Color:Black ;RoHS Compliant: Yes
SP508/1.2/BLACK 制造商:Farnell / Pro-Power 功能描述:HEAT SHRINK 50.8MM BLACK 1.2M
SP508/1.2/BLUE 制造商:Farnell / Pro-Power 功能描述:HEAT SHRINK 50.8MM BLUE 1.2M
SP508/1.2/BLUE 制造商:Farnell / Pro-Power 功能描述:HEAT SHRINK 50.8MM BLUE 1.2M
SP508/1.2/CLEAR 制造商:Farnell / Pro-Power 功能描述:HEAT SHRINK 50.8MM CLEAR 1.2M
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