ICL3243EIA Datasheet, PDF (19/33 Pages) Intersil Corporation – ±15kV ESD Protected, +3V to +5.5V, 1μA, 250kbps, RS-232 Transmitters/Receivers

ICL3221E, ICL3222E, ICL3223E, ICL3232E, ICL3241E, ICL3243E
output voltages under increasing load current. The
on-chip switching regulator ensures the transmitters will
supply at least ±5V during worst case conditions (15mA
for paralleled V+ transmitters, 7.3mA for single V-
transmitter). The Automatic Power-Down feature does
not work with a mouse, so FORCEOFF and FORCEON
should be connected to V_CC.
6
5
4
V_OUT+
3
2
V_CC = 3.0V
1
T1
0
-1
T2
-2
-3
-4 ^{VCC T3}
-5
-6
012
V_OUT+
ICL3241E, ICL3243E
V_OUT -
V_OUT -
3 4 5 6 7 8 9 10
LOAD CURRENT PER TRANSMITTER (mA)
FIGURE 9. TRANSMITTER OUTPUT VOLTAGE vs LOAD
CURRENT (PER TRANSMITTER, i.e.,
DOUBLE CURRENT AXIS FOR TOTAL
V_OUT+ CURRENT)
High Data Rates
The ICL32xxE maintain the RS-232 ±5V minimum
transmitter output voltages even at high data rates.
Figure 10 details a transmitter loopback test circuit, and
Figure 11 illustrates the loopback test result at 120kbps.
For this test, all transmitters were simultaneously driving
RS-232 loads in parallel with 1000pF, at 120kbps.
Figure 12 shows the loopback results for a single
transmitter driving 1000pF and an RS-232 load at
250kbps. The static transmitters were also loaded with
an RS-232 receiver.
V_CC
0.1µF ⁺
+
C₁
+
C₂
C1+
V_CC
V+
C1- ICL32xxE
C2+
V-
C2-
T_IN
T_OUT
R_OUT
R_IN
+
C₃
+C⁴
1000pF
EN
5K
V_CC
SHDN OR
FORCEOFF
FIGURE 10. TRANSMITTER LOOPBACK TEST CIRCUIT
5V/DIV
T1_IN
T1_OUT
R1_OUT
V_CC = +3.3V
C1 - C4 = 0.1µF
5µs/DIV
FIGURE 11. LOOPBACK TEST AT 120kbps
5V/DIV
T1_IN
T1_OUT
R1_OUT
V_CC = +3.3V
C1 - C4 = 0.1µF
2µs/DIV
FIGURE 12. LOOPBACK TEST AT 250kbps
Interconnection with 3V and 5V
Logic
The ICL32XX directly interface with 5V CMOS and TTL
logic families. Nevertheless, with the ICL32XX at 3.3V,
and the logic supply at 5V, AC, HC, and CD4000 outputs
can drive ICL32XX inputs, but ICL32XX outputs do not
reach the minimum V_IH for these logic families. See
Table 4 for more information.
TABLE 4. LOGIC FAMILY COMPATIBILITY WITH
VARIOUS SUPPLY VOLTAGES
SYSTEM
POWER-SUPPLY
VOLTAGE
(V)
V_CC
SUPPLY
VOLTAGE
(V)
COMPATIBILITY
3.3
3.3
Compatible with all CMOS
families.
5
5
Compatible with all TTL and
CMOS logic families.
19
FN4910.21
February 22, 2010