MAX3224EPP Maxim Integrated, MAX3224EPP Datasheet - Page 9

• Manufacturer Part Number: MAX3224EPP
• Description: RS-232 Interface IC
• Manufacturer: Maxim Integrated
• Series: MAX3224, MAX3225, MAX3226, MAX3227, MAX3244, MAX3245r

Specifications of MAX3224EPP

• Data Rate: 250 Kbps
• Operating Supply Voltage: 3 V to 5.5 V
• Supply Current: 1 mA
• Operating Temperature Range: 0 C to + 70 C
• Function: Transceiver
• Number Of Drivers: 2
• Number Of I/os: 8
• Number Of Receivers: 2
• Propagation Delay Time Ns: 0.15 us
• Shutdown: Yes

Maxim Integrated
The receivers convert RS-232 signals to CMOS-logic
output levels. The MAX3224–MAX3227 feature inverting
outputs that always remain active (Table 1). The
MAX3244/MAX3245 have inverting three-state outputs
that are high impedance when shut down (FORCEOFF
= GND) (Table 1).
The MAX3244/MAX3245 feature an extra, always
active, noninverting output, R2OUTB. R2OUTB output
monitors receiver activity while the other receivers are
high impedance, allowing Ring Indicator applications to
be monitored without forward biasing other devices
connected to the receiver outputs. This is ideal for sys-
tems where V
accommodate peripherals such as UARTs (Figure 2).
Table 1. Output Control Truth Table
(AutoShutdown™)
X = Don’t care
* INVALID connected to FORCEON
** INVALID connected to FORCEON and FORCEOFF
AutoShutdown is a trademark of Maxim Integrated Products, Inc.
Shutdown
(Forced Off)
Normal
Operation
(Forced On)
Normal
Operation
(AutoShutdown
Plus)
Shutdown (Auto-
Shutdown Plus)
Normal
Operation
Normal
Operation
Shutdown
Normal
Operation
(AutoShutdown)
Shutdown
OPERATION
STATUS
RS-232 Transceivers with AutoShutdown Plus
MAX3224–MAX3227/MAX3244/MAX3245
CC
FORCEON
1µA Supply Current, 1Mbps, 3.0V to 5.5V,
INVALID*
INVALID*
INVALID*
INVALID*
INVALID*
is set to ground in shutdown to
X
1
0
0
FORCEOFF
INVALID**
INVALID**
RS-232 Receivers
0
1
1
1
1
1
1
RECEIVER
LEVEL
VALID
Yes
Yes
No
No
X
X
X
X
X
TRANSMITTER
RECEIVER OR
EDGE WITHIN
30sec
Yes
Yes
No
No
X
X
X
X
X
The MAX3224–MAX3227/MAX3244/MAX3245 feature
an INVALID output that is enabled low when no valid
RS-232 voltage levels have been detected on all receiv-
er inputs. Because INVALID indicates the receiver
input’s condition, it is independent of FORCEON and
FORCEOFF states (Figures 3 and 4).
The MAX3224–MAX3227/MAX3244/MAX3245 achieve a
1µA supply current with Maxim’s AutoShutdown Plus
feature, which operates when FORCEOFF is high and a
FORCEON is low. When these devices do not sense a
valid signal transition on any receiver and transmitter
input for 30sec, the on-board charge pumps are shut
down, reducing supply current to 1µA. This occurs if the
RS-232 cable is disconnected or if the connected
T_OUT
High-Z
High-Z
High-Z
High-Z
Active
Active
Active
Active
Active
(MAX3224/
MAX3225/
MAX3226/
MAX3227)
R_OUT
Active
Active
Active
Active
Active
Active
Active
Active
Active
AutoShutdown Plus Mode
(MAX3244/
MAX3245)
R_OUT
High-Z
High-Z
Active
Active
Active
Active
Active
Active
Active
(MAX3244/
MAX3245)
R2OUTB
Active
Active
Active
Active
Active
Active
Active
Active
Active
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