MAX3030E–MAX3033E
sents the minimum parasitic capacitance that would
exist in a typical application. In most cases, more
capacitance exists in the system and reduces the mag-
nitude of the glitch. During a “hot-swap” event when the
driver is connected to the line and is powered up, the
driver must not cause the differential signal to drop
below 200mV (Figures 12 and 13).
Operation of Enable Pins
The MAX3030E–MAX3033E family has two enable-func-
tional versions.
The MAX3030E/MAX3031E are compatible with
26LS31, where the two enable signals control all four
transmitters (global enable).
The MAX3032E/MAX3033E are compatible with the
SN75174. EN1&2 controls transmitters 1 and 2, and EN
3&4 controls transmitters 3 and 4 (dual enable).
Typical Applications
The MAX3030E–MAX3033E offer optimum performance
when used with the MAX3094E/MAX3096 3.3V quad
differential line receivers. Figure 14 shows a typical RS-
422 connection for transmitting and receiving data.
±15kV ESD-Protected, 3.3V Quad
RS-422 Transmitters
10 ______________________________________________________________________________________
4µs/div
DO_+
DO_+ - DO_-
DO_-
V
CC
1V/div
Figure 12. Differential Power-Up Glitch (0.1V/µs)
1.0µs/div
DO_+
DO_+ - DO_-
DO_-
V
CC
1V/div
Figure 13. Differential Power-Up Glitch (1V/µs)
EN EN TX1 TX2 TX3 TX4 MODE
0 0 Active Active Active Active All transmitters active
0 1 High-Z High-Z High-Z High-Z All transmitters disabled
1 0 Active Active Active Active All transmitters active
1 1 Active Active Active Active All transmitters active
Table 1. MAX3030E/MAX3031E Transmitter Controls
EN1&2 EN3&4 TX1 TX2 TX3 TX4 MODE
0 0 High-Z High-Z High-Z High-Z All transmitters disabled
0 1 High-Z High-Z Active Active Tx 3 and 4 active
1 0 Active Active High-Z High-Z Tx 1 and 2 active
1 1 Active Active Active Active All transmitters active
Table 2. MAX3032E/MAX3033E Transmitter Controls
