SP2209E Datasheet, PDF (13/17 Pages) Sipex Corporation – High ESD Dual Port RS-232 Transceiver

APPLICATIONS
With six drivers and ten receivers, the
SP2209E device is ideal for applications
requiring two RS-232 ports such as in
desktop or portable computers. Refer to
Figure 13. For typical DB9 serial ports for
Data Terminal Equipment (DTE) to Data
Circuit Terminating Equipment (DCE)
interface implementation, 2 data lines,
TxD and RxD, and 6 control lines, RTS,
DTR, DSR, CTS, and RI, are required.
The straight-through pinout for data lines
in the SP2209E device allows a simplified
PCB layout allowing ground lines to sepa-
rate the signal lines and ground planes
to be placed beneath the IC without the
complication of a multi-layer PCB layout.
A receiver from each port, R5INA and
R5INB, are active while the rest of the
channels are powered down. This allows
the SP2209E device to monitor peripheral
devices while the rest of the system is in
a power-saving standby mode. Failsafe
receiver outputs are pulled high if the
receiver inputs are left unconnected or at
zero input. The SP2209E device can be
implemented as a power management
device to wake up the entire system when
any communication is initiated in periph-
eral devices. The SP2209E device has a
low standby current of 100µA.
A standard serial mouse can be powered
from the SP2209E drivers. Two driver
outputs connected in parallel and set to
V_OH can be used to supply power to the V+
pin of the mouse. The third driver is set
to V_OL to link current from the V- terminal.
Typical mouse specifications are 10mA at
+6V and 5mA at -6V.
LapLink Compatibility
The SP2209E can operate up to 460kbps
data under maximum driveload conditions
of C_L = 1000pF and R_L = 3kΩ at minimum
power supply voltages.
APPLICATIONS
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
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