+5V-Powered, Multichannel
RS-232 Drivers/Receivers
MAX220–MAX249
ꢅables ±aꢀ±d define the control statesꢂ ꢅhe ꢄMAXꢁꢁ
has no control pins and is not included in these tablesꢂ
ꢅhe ꢄMAXꢁ9 provides ten receivers and six drivers with
four control pinsꢂ ꢅhe ENRA and ENRB receiver enable
inputs each control five receiver outputsꢂ ꢅhe ENTA
and ENTB transmitter enable inputs control three dri-
vers eachꢂ ꢅhere is no always-active receiverꢂ ꢅhe
device enters shutdown mode and transmitters go into
a three-state mode with a logic high on both ENTA and
ENTBꢂ In shutdown mode% active receivers operate in a
low-power receive mode at data rates up to X1kb/sꢂ
ꢅhe ꢄMAXꢁ6 has ten receivers and eight drivers with
two control pins% each controlling one side of the
deviceꢂ M logic high at the M-side control input (ENA)
causes the four M-side receivers and drivers to go into
a three-state modeꢂ Similarly% the B-side control input
(ENB) causes the four B-side drivers and receivers to
go into a three-state modeꢂ Ms in the ꢄMAXꢁ5% one M-
side and one B-side receiver (RM5 and RB5) remain
active at all timesꢂ ꢅhe entire device is put into shut-
down mode when both the M and B sides are disabled
(ENA = ENB = +5V)ꢂ
Applications Information
µigures 5 through X5 show pin configurations and typi-
cal operating circuitsꢂ In applications that are sensitive
to power-supply noise% V
ground with a capacitor of the same value as C± and
CX connected as close as possible to the deviceꢂ
should be decoupled to
CC
ꢅhe ꢄMAXꢁ4 provides nine receivers and eight drivers
with four control pinsꢂ ꢅhe ENRA and ENRB receiver
enable inputs each control four receiver outputsꢂ ꢅhe
ENTA and ENTB transmitter enable inputs each control
four driversꢂ ꢅhe ninth receiver (RB5) is always activeꢂ
ꢅhe device enters shutdown mode with a logic high on
both ENTA and ENTBꢂ
ꢅhe ꢄMAXꢁ8 provides eight receivers and eight drivers
with four control pinsꢂ ꢅhe ENRA and ENRB receiver
enable inputs each control four receiver outputsꢂ ꢅhe
ENTA and ENTB transmitter enable inputs control four
drivers eachꢂ ꢅhis part does not have an always-active
receiverꢂ ꢅhe device enters shutdown mode and trans-
mitters go into a three-state mode with a logic high on
both ENTA and ENTBꢂ
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