SP3223EBCA-L/TR Exar Corporation, SP3223EBCA-L/TR Datasheet - Page 9

• Manufacturer Part Number: SP3223EBCA-L/TR
• Description: Intelligent +3.0V To +5.5V RS-232 Transceivers
• Manufacturer: Exar Corporation
• Type: Transceiverr

Specifications of SP3223EBCA-L/TR

• Number Of Drivers/receivers: 2/2
• Protocol: RS232
• Voltage - Supply: 3 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 20-SSOP (0.200", 5.30mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DESCRIPTION
The SP3223 is a 2-driver/2-receiver device
ideal for portable or handheld applications.
The SP3223 transceivers meet the EIA/TIA-
232 and ITU-T V.28/V.24 communication
protocols and can be implemented in battery-
powered, portable, or handheld applications
such as notebook or handheld computers.
The SP3223 devices feature Exar's propri-
etary and patented (U.S.-- 5,306,954) on-
board charge pump circuitry that generates
±5.5V RS-232 voltage levels from a single
+3.0V to +5.5V power supply.
These devices are an ideal choice for power
sensitive designs. Featuring AUTO ON-LINE
circuitry, the SP3223 reduces the power sup-
ply drain to a µA supply current. In many
portable or handheld applications, an RS-232
cable can be disconnected or a connected
peripheral can be turned off. Under these
conditions, the internal charge pump and
the drivers will be shut down. Otherwise, the
system automatically comes online. This
feature allows design engineers to address
Figure 3. Interface Circuitry Controlled by Micropro-
cessor Supervisory Circuit
RESET
Serial µC
UART
Supervisor
or
µP
IC
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)668-707 • www.exar.com
TTL/CMOS OUTPUTS
TTL/CMOS INPUTS
V
IN
C2
C1
C5
+
+
+
V
CC
0.1µF
0.1µF
0.1µF
11
12
15
10
20
14
11
2
4
5
6
C1+
C1-
R
C2+
C2-
T
T
R
EN
SHUTDOWN
ONLINE
STATUS
1
2
1
2
IN
IN
OUT
OUT
SP3223E
V
V
GND
CC
CC
19
18
5KΩ
5KΩ
T
T
1
2
OUT
OUT
R
R
V+
1
2
V-
IN
IN
17
16
3
7
8
9
C3
C4
RS-232
OUTPUTS
+
+
RS-232
INPUTS
0.1µF
0.1µF
®
9
power saving concerns without major design
changes.
THEORY OF OPERATION
The SP3223 series is made up of four basic
circuit blocks:
. Drivers, 2. Receivers, 3. The Exar pro-
prietary charge pump, and 4. AUTO ON-
LINE
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 degrada-
tion in reliability. These drivers comply with
the EIA-TIA-232F and all previous RS-232
versions. Unused driver inputs should be
connected to GND or V
The drivers can guarantee output data
rates fully loaded with 3kΩ in parallel with
000pF, (SP3223EU, C
compatibility with PC-to-PC communication
software.
The slew rate of the driver output on the
E and EB versions is internally limited to a
maximum of 30V/µs in order to meet the EIA
standards (EIA RS-232D 2..7, Paragraph 5).
The Slew Rate of EU version is not limited
to enable higher speed data transfers. The
transition of the loaded output from HIGH to
LOW also meets the monotonicity require-
ments of the standard.
Figure 4 shows a loopback test circuit used
to test the RS-232 Drivers. Figure 15 shows
the test results where one driver was active
at 250kbps and all drivers are loaded with
an RS-232 receiver in parallel with a 000pF
capacitor. RS-232 data transmission rate of
20kbps to Mbps provide compatibility with
designs in personal computer peripherals
and LAN applications.
®
circuitry.
CC
L
= 250pF) ensuring
SP3223E/EB/EU_00_20
.