+5V-Powered, Multichannel RS-232
Drivers/Receivers
0–MAX249
Table 1d. MAX247/MAX248/MAX249 Control Pin Configurations
TRANSMITTERS
RECEIVERS
RA1–RA4
MAX247 TA1–TA4 TB1–TB4
MAX248 TA1–TA4 TB1–TB4
MAX249 TA1–TA3 TB1–TB3
RB1–RB5
RB1–RB4
RB1–RB5
OPERATION
STATUS
ENTA ENTB ENRA ENRB
RA1–RA4
RA1–RA5
0
0
0
0
0
0
0
0
±
±
±
±
0
0
0
0
±
±
±
±
0
0
0
0
0
0
±
±
0
0
±
±
0
0
±
±
0
±
0
±
0
±
0
±
0
±
0
±
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
All Active All Active All Active
All Active
All High-Z, except
RB5 stays active on
MAX247
All Active All Active All Active
All Active All Active All High-Z
All Active All Active All High-Z
All Active All High-Z All Active
All Active All High-Z All Active
All Active All High-Z All High-Z
All Active All High-Z All High-Z
All High-Z All Active All Active
All High-Z All Active All Active
All High-Z All Active All High-Z
All High-Z All Active All High-Z
All Active
All High-Z, except
RB5 stays active on
MAX247
All Active
All High-Z, except
RB5 stays active on
MAX247
All Active
All High-Z, except
RB5 stays active on
MAX247
All Active
All High-Z, except
RB5 stays active on
MAX247
All Active
All High-Z, except
RB5 stays active on
MAX247
Low-Power
All High-Z All High-Z
Receive Mode
Low-Power
Receive Mode
±
±
±
±
±
±
±
±
0
0
±
±
0
±
0
±
Shutdown
Shutdown
Shutdown
Shutdown
All High-Z, except
RB5 stays active on
MAX247
Low-Power
All High-Z All High-Z
Receive Mode
Low-Power
Receive Mode
All High-Z All High-Z All High-Z
All High-Z All High-Z All High-Z
All High-Z, except
RB5 stays active on
MAX247
______________________________________________________________________________________ 13
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
