- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄360997 > ISO422P-U Transceiver PDF資料下載
參數(shù)資料
| 型號(hào)： | ISO422P-U |
| 元件分類： | 收發(fā)器 |
| 英文描述： | Transceiver |
| 中文描述： | 收發(fā)器 |
| 文件頁數(shù)： | 5/9頁 |
| 文件大?。?/td> | 246K |
| 代理商： | ISO422P-U |
ISO422
SBOS113A
5
OPERATION
ISO422 is an isolated, full-duplex bus transceiver which is
compatible with three-wire data bus systems using EIA
standards RS-422-A and RS-485. It is based on Burr-Brown
’
s
capacitive barrier technology. The data bus input is designed
to present a very high impedance to the data bus, thus
allowing a virtually unlimited number of receivers on any
data bus section. To allow this feature, the data bus input is
limited to a common-mode range within the magnitude of
the supplies. This limitation requires that all nodes on the
bus are referenced to a common ground. However, systems
attached to the bus through ISO422, are isolated up to
1500Vrms and may, therefore, have local floating ground
potentials up to this isolation voltage. The circuit encodes all
data passed across the barrier to ensure that the input values
and control signals are correctly passed across the barrier
under all power up conditions. The ISO422 also allows data
recovery to the current input state, after any transient upset.
TRANSMIT
Data is passed from the D input to the data bus outputs after
a barrier transmission delay (t
DD
) when the DE input is
HIGH. When DE is LOW, the data bus drivers are switched
off, and assume the high impedance state. When enabling
the data bus output, i.e., switching DE from LOW to HIGH,
the enable signal is passed directly across the barrier and
enables the output, after a barrier transmission delay and
output enable time (t
DLZ
/t
DHZ
). Similarly, when disabling the
data bus output, i.e., switching DE from HIGH to LOW, the
disable signal is passed directly across the barrier and
disables the output after a barrier transmission delay and
output disable time (t
DLZ
/t
DHZ
).
active. The receive enable/disable time is simply the time to
enable/disable the R output (t
RLZ
) and does not require any
additional barrier transmission time.
FIGURE 1. ISO422 Data Transmit.
FIGURE 2. ISO422 Data Receive.
DATA CORRUPTION
If, due to transient upset, the data passed across the barrier
is corrupted, the data will be restored within 100ns from the
end of the corrupting signal.
SYNCHRONIZATION
The data transmitted across the barrier is coded using an
internal clock. This clock also captures the incoming asyn-
chronous data and synchronizes it to the clock edges. This
will give rise to an rms propagation delay jitter of approxi-
mately 50ns.
LOOPBACK
A loopback function is provided by the LBE input. If this
input is HIGH, then enabling both the transmitter and the
receiver will cause the device to route the D input to the R
output, in addition to the data bus outputs. Data on the
incoming bus is ignored. This feature allows a simple con-
nection test to be performed during any application. When
LBE is LOW, transmit and receive will operate in the normal
full-duplex mode.
DATA BUS CONNECTION
ISO422 can be used in half duplex, or full duplex data
communication bus systems. It is capable of continuously
driving a 54
load, equivalent to a double-terminated trans-
mission line, at the fully specified data rate. When connect-
ing to the data bus, the voltage on the A and B input lines
must remain between V
SB
and GND
B
. This can be achieved
by using a common bus ground connection, such as GND
B
,
as shown in Figures 5 and 6.
For any system connected to the bus, the isolation provided
by ISO422 allows the independent local ground potential to
be as high as 1500Vrms with respect to the date bus ground
reference. This feature replaces the limited +12V to
–
7V
range of the RS-485 standard with the full-isolation voltage
capability of the ISO422.
RECIEVE
The receive data is determined by the data bus differential
signal after a barrier transmission delay (t
RZL
). When the
difference between the A input and the B input (A-B) is
greater than +200mV, the R output will be HIGH. If A-B is
more negative than
–
200mV, the R output is undefined.
Since the reciver has a high impedance input, no disable
signal is required for the data bus input, which is always
DE
D
Y
Z
t
DZL
t
DD
t
DLZ
t
DZH
t
DHZ
t
DD
t
RZL
t
RLZ
t
RZH
t
RZH
t
RLH
t
RHL
A
B
R
RE
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ISO508 | Uni-Directional ISOLATED DIGITAL COUPLERS |
| ISO508P | Uni-Directional ISOLATED DIGITAL COUPLERS |
| ISO508P-U | Uni-Directional ISOLATED DIGITAL COUPLERS |
| ISO806 | Isolated 12-Bit Sampling ANALOG-TO-DIGITAL CONVERTER |
| ISO806P | Isolated 12-Bit Sampling ANALOG-TO-DIGITAL CONVERTER |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ISO422P-U(1) | 制造商:BB 制造商全稱:BB 功能描述:DIFFERENTIAL BUS TRANSCEIVER |
| ISO485 | 制造商:BB 制造商全稱:BB 功能描述:Isolated RS-485 DIFFERENTIAL BUS TRANSCEIVER |
| ISO485EVM | 功能描述:界面開發(fā)工具 ISO485 Eval Mod RoHS:否 制造商:Bourns 產(chǎn)品:Evaluation Boards 類型:RS-485 工具用于評(píng)估:ADM3485E 接口類型:RS-485 工作電源電壓:3.3 V |
| ISO485P | 制造商:Rochester Electronics LLC 功能描述:ISOLATED RS/485 INTERFACE - Bulk |
| ISO4X250H1 | 制造商:HELLERMANNTYTON 功能描述:ISOLATOR MOUNT FOR 1/4" TUBING 制造商:HellermannTyton 功能描述: 制造商:HellermannTyton 功能描述:Cable Accessories Isolator Mount Thermoplastic Black Bag |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。