SP3243EET-L Exar Corporation, SP3243EET-L Datasheet - Page 12

• Manufacturer Part Number: SP3243EET-L
• Description: IC TXRX RS232 INTELLIGNT 28WSOIC
• Manufacturer: Exar Corporation
• Type: Transceiverr

Specifications of SP3243EET-L

• Package / Case: 28-SOIC (0.300", 7.50mm Width)
• Number Of Drivers/receivers: 3/5
• Protocol: RS232
• Voltage - Supply: 3 V ~ 5.5 V
• Mounting Type: Surface Mount
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Function: Transceiver
• Mounting Style: SMD/SMT
• Supply Current: 1 uA
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Logic Type: RS-232 Transceivers
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 1016-1122-5

Figure 20. AUTO ON-LINE
Date: 2/05/06
The second stage of the AUTO ON-LINE
cuitry, shown in Figure 29, processes all the
receiver's R
lated delay that disables the device to a 1μA
supply current.
The STATUS pin goes to a logic LOW when the
cable is disconnected, the external transmitters
are disabled, or the SHUTDOWN pin is
invoked. The typical accumulated delay is around
20μs.
When the SP3243 drivers or internal charge
pump are disabled, the supply current is reduced
to 1μA. This can commonly occur in hand-held
or portable applications where the RS-232 cable
is disconnected or the RS-232 drivers of the
connected peripheral are turned off.
The first stage, shown in Figure 28, detects an
inactive input. A logic HIGH is asserted on
R
external transmitters are disabled. Otherwise,
R
duplicated for each of the other receivers.
X
X
INACT if the cable is disconnected or the
INACT will be at a logic LOW. This circuit is
X
INACT signals with an accumu-
RS-232 OUTPUT
RS-232 INPUT
®
Timing Waveforms
VOLTAGES
RECEIVER
VOLTAGES
STATUS
DRIVER
SP3243 +3.0V to +5.5V RS-232 Transceivers
+2.7V
-2.7V
V
+5V
-5V
CC
0V
0V
0V
®
cir-
t
12
STSL
The AUTO ON-LINE
the SHUTDOWN pin. If this pin is a logic LOW,
the AUTO ON-LINE
regardless of the logic state of the ONLINE pin.
Table 3 summarizes the logic of the AUTO ON-
LINE
the SP3243 driver and receiver outputs can be
found in Table 2.
The STATUS pin outputs a logic LOW signal
if the device is shutdown. This pin goes to a
logic HIGH when the external transmitters are
enabled and the cable is connected.
When the SP3243 devices are shut down, the
charge pumps are turned off. V+ charge pump
output decays to V
GND. The decay time will depend on the size of
capacitors used for the charge pump. Once in
shutdown, the time required to exit the shut
down state and have valid V+ and V- levels is
typically 200μs.
For easy programming, the STATUS can be
used to indicate DSR or a Ring Indicator signal.
Tying ONLINE and SHUTDOWN together
will bypass the AUTO ON-LINE
this connection acts like a shutdown input pin.
t
ONLINE
®
t
STSH
operating modes. The truth table logic of
W
H
U
D
O
N
S
T
CC
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, the V- output decays to
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© Copyright 2006 Sipex Corporation
function will not operate
mode can be disabled by
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circuitry so