SP3243EET-L Exar Corporation, SP3243EET-L Datasheet - Page 8

• 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

DESCRIPTION
The SP3243 transceivers meet the EIA/TIA-232
and ITU-T V.28/V.24 communication protocols
and can be implemented in battery-powered,
portable, or hand-held applications such as note-
book or palmtop computers. The SP3243 de-
vices feature Sipex's proprietary and patented
(U.S.-- 5,306,954) on-board charge pump cir-
cuitry that generates ±5.5V RS-232 voltage lev-
els from a single +3.0V to +5.5V power supply.
The SP3243EU devices can operate at a data rate
of 1000kbps fully loaded.
The SP3243 is a 3-driver/5-receiver device, ideal
for portable or hand-held applications. The
SP3243 includes one complementary
always-active receiver that can monitor an
external device (such as a modem) in shutdown.
This aids in protecting the UART or serial
controller IC by preventing forward biasing
of the protection diodes where V
disconnected.
The SP3243 series is an ideal choice for power
sensitive designs. The SP3243 devices feature
Figure 16. Interface Circuitry Controlled by Micropro-
cessor Supervisory Circuit
Date: 2/05/06
RESET
Serial μC
UART
Supervisor
or
μP
IC
V IN
RTS
C2
TxD
DTR
C1
RxD
C5
CTS
DCD
DSR
RI
+
+
+
V
0.1μF
0.1μF
0.1μF
CC
28
24
14
13
12
20
19
18
17
16
15
22
23
21
1
2
C1+
C1-
C2+
C2-
T
T
T
R
R
R
STATUS
R
R
SHUTDOWN
ONLINE
R
1
2
3
2
1
2
3
4
IN
IN
OUT
5
IN
OUT
OUT
OUT
OUT
OUT
SP3243
V
V
GND
CC
CC
26
25
5KΩ
5KΩ
5KΩ
5KΩ
5KΩ
SP3243 +3.0V to +5.5V RS-232 Transceivers
T
T
T
1
2
3
R
R
R
R
R
OUT
OUT
OUT
CC
1
2
3
4
5
V+
V-
IN
IN
IN
IN
IN
10
11
4
5
6
7
8
27
3
9
may be
C3
C4
RS-232
OUTPUTS
RS-232
INPUTS
+
+
0.1μF
0.1μF
8
AUTO ON-LINE
power supply drain to a 1μA supply current. In
many portable or hand-held applications, an RS-
232 cable can be disconnected or a connected
peripheral can be turned off. Under these condi-
tions, the internal charge pump and the drivers
will be shut down. Otherwise, the system auto-
matically comes online. This feature allows de-
sign engineers to address power saving concerns
without major design changes.
THEORY OF OPERATION
The SP3243 series is made up of four basic
circuit blocks:
1. Drivers
2. Receivers
3. the Sipex proprietary charge pump, and
Drivers
The drivers are inverting level transmitters that
convert TTL or CMOS logic levels to 5.0V EIA/
TIA-232 levels with an inverted sense relative to
the input logic levels. Typically, the RS-232
output voltage swing is +5.4V with no load and
+5V minimum fully loaded. The driver outputs
are protected against infinite short-circuits to
ground without degradation in reliability. These
drivers comply with the EIA-TIA-232-F and all
previous RS-232 versions. Unused drivers in-
puts should be connected to GND or V
The drivers have a minimum data rate of 250kbps
(EB) or 1000kbps (EU) fully loaded.
Figure 17 shows a loopback test circuit used to
test the RS-232 Drivers. Figure 18 shows the test
results where one driver was active at 1Mbps and
all three drivers loaded with an RS-232 receiver
in parallel with a 250pF capacitor. Figure 19
4. AUTO ON-LINE
®
circuitry which reduces the
®
© Copyright 2006 Sipex Corporation
circuitry.
CC
.