+5V-Powered, Multichannel RS-232
Drivers/Receivers
Table 1d. MAX247/MAX248/MAX249 Control Pin Configurations
TRANSMITTERS
ENTA ENTB ENRA ENRB
OPERATION
STATUS
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
MAX247
MAX248
MAX249
0
0
0
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
TA1–TA4
TA1–TA4
TA1–TA3
All Active
All Active
All Active
All Active
All Active
All Active
All Active
All Active
All High-Z
All High-Z
All High-Z
All High-Z
TB1–TB4
TB1–TB4
TB1–TB3
All Active
All Active
All Active
All Active
All High-Z
All High-Z
All High-Z
All High-Z
All Active
All Active
All Active
All Active
RECEIVERS
RA1–RA4
RA1–RA4
RA1–RA5
All Active
All Active
All High-Z
All High-Z
All Active
All Active
All High-Z
All High-Z
All Active
All Active
All High-Z
All High-Z
RB1–RB5
RB1–RB4
RB1–RB5
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
All Active
All High-Z, except
RB5 stays active on
MAX247
Low-Power
Receive Mode
All High-Z, except
RB5 stays active on
MAX247
Low-Power
Receive Mode
All High-Z, except
RB5 stays active on
MAX247
MAX220–MAX249
1
1
0
0
Shutdown
All High-Z
All High-Z
Low-Power
Receive Mode
1
1
0
1
Shutdown
All High-Z
All High-Z
Low-Power
Receive Mode
1
1
1
0
Shutdown
All High-Z
All High-Z
All High-Z
1
1
1
1
Shutdown
All High-Z
All High-Z
All High-Z
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
