+5V-Powered, Multichannel
RS-232 Drivers/Receivers
MAX220–MAX249
Table 1d. MAX247/MAX248/MAX249 Control Pin Configurations
TRANSMITTERS
MAX247 TA1–TA4 TB1–TB4
MAX248 TA1–TA4 TB1–TB4
MAX249 TA1–TA3 TB1–TB3
RECEIVERS
RA1–RA4
RA1–RA4
RA1–RA5
RB1–RB5
RB1–RB4
RB1–RB5
OPERATION
STATUS
ENTA ENTB ENRA ENRB
1
1
1
1
1
1
1
1
±
±
±
±
1
1
1
1
±
±
±
±
1
1
1
1
1
1
±
±
1
1
±
±
1
1
±
±
1
±
1
±
1
±
1
±
1
±
1
±
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Normal Operation
Mll Mctive Mll Mctive Mll Mctive
Mll Mctive
Mll High-Z% except
RB5 stays active on
ꢄMAXꢁ4
Mll Mctive Mll Mctive Mll Mctive
Mll Mctive Mll Mctive Mll High-Z
Mll Mctive Mll Mctive Mll High-Z
Mll Mctive Mll High-Z Mll Mctive
Mll Mctive Mll High-Z Mll Mctive
Mll Mctive Mll High-Z Mll High-Z
Mll Mctive Mll High-Z Mll High-Z
Mll High-Z Mll Mctive Mll Mctive
Mll High-Z Mll Mctive Mll Mctive
Mll High-Z Mll Mctive Mll High-Z
Mll High-Z Mll Mctive Mll High-Z
Mll Mctive
Mll High-Z% except
RB5 stays active on
ꢄMAXꢁ4
Mll Mctive
Mll High-Z% except
RB5 stays active on
ꢄMAXꢁ4
Mll Mctive
Mll High-Z% except
RB5 stays active on
ꢄMAXꢁ4
Mll Mctive
Mll High-Z% except
RB5 stays active on
ꢄMAXꢁ4
Mll Mctive
Mll High-Z% except
RB5 stays active on
ꢄMAXꢁ4
Low-Power
Mll High-Z Mll High-Z
Receive ꢄode
Low-Power
Receive ꢄode
±
±
±
±
±
±
±
±
1
1
±
±
1
±
1
±
Shutdown
Shutdown
Shutdown
Shutdown
Mll High-Z% except
RB5 stays active on
ꢄMAXꢁ4
Low-Power
Mll High-Z Mll High-Z
Receive ꢄode
Low-Power
Receive ꢄode
Mll High-Z Mll High-Z Mll High-Z
Mll High-Z Mll High-Z Mll High-Z
Mll High-Z% except
RB5 stays active on
ꢄMAXꢁ4
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