Datasheet

Transmitter Outputs Recovering
from Shutdown
Figure 3 shows two transmitter outputs recovering from
shutdown mode. As they become active, the two trans-
mitter outputs are shown going to opposite RS-232 levels
(one transmitter input is high; the other is low). Each
transmitter is loaded with 3kΩ in parallel with 2500pF.
The transmitter outputs display no ringing or undesirable
transients as they come out of shutdown. Note that the
transmitters are enabled only when the magnitude of V-
exceeds approximately -3.0V.
Mouse Drivability
The MAX3241E is designed to power serial mice while
operating from low-voltage power supplies. It has been
tested with leading mouse brands from manufacturers
such as Microsoft and Logitech. The MAX3241E success-
fully drove all serial mice tested and met their current and
voltage requirements.
Figure 7. Loopback Test Circuit
Figure 8. MAX3241E Loopback Test Result at 120kbps
Figure 9. MAX3241E Loopback Test Result at 250kbps
Figure 10. MAX3237E Loopback Test Result at 1000kbps
(MBAUD = V
CC
)
MAX3222E
MAX3232E
MAX3237E
MAX3241E
MAX3246E
5kΩ
R_ IN
R_ OUT
C2-
C2+
C1-
C1+
V-
V+
V
CC
C4
C3
C1
C2
0.1µF
V
CC
T_ OUT
T_ IN
GND
1000pF
2µs/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
V
CC
= 3.3V
C1–C4 = 0.1µF
2µs/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
V
CC
= 3.3V, C1–C4 = 0.1µF
+5V
0
+5V
0
-5V
+5V
0
T_IN
T_OUT
5kΩ + 250pF
R_OUT
400ns/div
V
CC
= 3.3V
C1–C4 = 0.1µF
www.maximintegrated.com
Maxim Integrated │ 14
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers