SP3203ECY-L Datasheet, PDF (9/16 Pages) Exar Corporation – 3V RS-232 Serial Transceiver with Logic Selector and 15kV ESD Protection

T1 IN 1
[
T
]
T
T1 OUT 2
T
T
R1 OUT 3
Ch1 5.00V Ch2 5.00V M 5.00msCh1 0V
Ch3 5.00V
Figure 3. Loopback Test Circuit result at 120Kbps
(All Drivers Fully Loaded)
[
T
]
T1 IN 1
T
T1 OUT 2
T
T
R1 OUT 3
Ch1 5.00V Ch2 5.00V M 2.50msCh1 0V
Ch3 5.00V
Figure 4. Loopback Test Circuit result at 250Kbps
(All Drivers Fully Loaded)
Current RS-232 serial transceivers are
designed with fixed 5V to 3.3V TTL input/
output voltage levels. The V_L function in the
SP3203E allows the end user to set the TTL
input/output voltage levels independent of
Vcc. By connecting V_L to the main logic bus
of system, the TTL input/output limits and
thresholds are reset to interface with the on
board low voltage logic circuitry.
Capacitor Selection Table:
Vcc (V)
C1 (µF) C2 - C4 (µF)
3.0 to 3.6
0.1
0.1
4.5 to 5.5
0.047
0.33
3.0 to 5.5
0.22
1
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • www.exar.com

SP3203E_100_120810