1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
Table 3. Required Capacitor Values
V
CC
0.1µF
MAX3221/MAX3223/MAX3243
V
CC
(V)
3.0 to 3.6
V
CC
C1
(µF)
0.1
0.047
0.1
C2, C3, C4
(µF)
0.1
0.33
0.47
C1+
C1
C1-
C2+
C2
C2-
V+
C3
4.5 to 5.5
3.0 to 5.5
MAX3221
MAX3223
MAX3243
V-
C4
Table 4. Logic Family Compatibility with
Various Supply Voltages
SYSTEM
POWER-
SUPPLY
VOLTAGE
(V)
3.3
V
CC
SUPPLY
VOLTAGE
(V)
T_ IN
T_ OUT
COMPATIBILITY
R_ OUT
0V
V
CC
EN (MAX3221/3)
R_ IN
5kΩ
3.3
5
1000pF
Compatible with all CMOS
families.
Compatible with all TTL and
CMOS-logic families.
Compatible with ACT and
HCT CMOS, and with TTL.
Incompatible with AC, HC,
or CD4000 CMOS.
5
FORCEOFF
GND
5
3.3
Figure 8. Loopback Test Circuit
T1IN
5V/div
T1IN
5V/div
T1OUT
5V/div
T1OUT
5V/div
R1OUT
5V/div
R1OUT
5V/div
5µs/div
V
CC
= +3.3V, 120kbps
C1–C4 = 0.1µF
V
CC
= +3.3V, 235kbps
C1–C4 = 0.1µF
2µs/div
Figure 9. Loopback Test Result at 120kbps
Figure 10. Loopback Test Result at 235kbps
______________________________________________________________________________________
11
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
