SP3223EB Datasheet, PDF (11/25 Pages) Sipex Corporation – Intelligent +3.0V to +5.5V RS-232 Transceivers

DEVICE: SP3223EB
SHUTDOWN
EN
0
0
0
1
1
0
1
1
T_XOUT R_XOUT
High Z Active
High Z High Z
Active Active
Active High Z
DEVICE: SP3243EB
SHUTDOWN T_XOUT R_XOUT R₂OUT
0
High Z High Z Active
1
Active Active Active
Table 2. SHUTDOWN and EN Truth Tables
Note: In AUTO ON-LINE^® Mode where ONLINE =
GND and SHUTDOWN = V_CC, the device will shut down
if there is no activity present at the Receiver inputs.
+3V to +5V
+
C5 0.1µF
+
C1 0.1µF
+
C2 0.1µF
TTL/CMOS
INPUTS
VCC
C1+
V+
C1-
C2+ _{SP3223EB V-}
SP3243EB
C2-
T₁IN
T₁OUT
T_XIN
T_XOUT
+
C3 0.1µF
C4 0.1µF
+
TTL/CMOS
OUTPUTS
VCC
To µP Supervisor
Circuit
R₁OUT
R₁IN
5kΩ
R_XOUT
EN
R_XIN
5kΩ
1000pF
SHUTDOWN
ONLINE
STATUS
GND
18
1000pF
Figure 17. Loopback Test Circuit for RS-232 Driver
Data Transmission Rates
The SP3223EB and SP3243EB drivers can main-
tain high data rates up to 250kbps fully loaded.
Figure 17. shows a loopback test circuit used to
test the SP3243EB RS-232 Drivers. Figure 18
shows the test results of the loopback circuit with
all three drivers active at 120kbps with typical
RS-232 loads in parallel with 1000pF capacitors.
Figure 19 shows the test results where one driver
was active at 250kbps and all three drivers loaded
with an RS-232 receiver in parallel with a 1000pF
capacitor. A solid RS-232 data transmission
rate of 250kbps provides compatibility with many
designs in personal computer peripherals and
LAN applications.
Receivers
The receivers convert ±5.0V EIA/TIA-232
levels to TTL or CMOS logic output levels. All
receivers have an inverting output that can be
disabled by using the EN pin.
Figure 18. Loopback Test Circuit All Drivers at 120kbps
Figure 19. Loopback Test Circuit One Driver at 250kbps
Date: 6/2/04
SP3223EB/3243EB +3.0V to +5.5V RS-232 Transceivers
11
© Copyright 2004 Sipex Corporation