MAX3245EEAI Maxim Integrated Products, MAX3245EEAI Datasheet - Page 10

• Manufacturer Part Number: MAX3245EEAI
• Description: IC TXRX RS232 1MBPS SHTDN 28SSOP
• Manufacturer: Maxim Integrated Products
• Type: Transceiverr

Specifications of MAX3245EEAI

• Number Of Drivers/receivers: 3/5
• Protocol: RS232
• Voltage - Supply: 3 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 28-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

The receivers convert RS-232 signals to CMOS-logic
output levels. The MAX3224E–MAX3227E feature
inverting outputs that always remain active (Table 1).
The MAX3244E/MAX3245E have inverting three-state
outputs that are high impedance when shut down
(FORCEOFF = GND) (Table 1).
The MAX3244E/MAX3245E 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).
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Table 1. Output Control Truth Table
X = Don’t care
* INVALID connected to FORCEON
** INVALID connected to FORCEON and FORCEOFF
10
(AutoShutdown)
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
______________________________________________________________________________________
CC
FORCEON
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
Yes
Yes
30s
No
No
X
X
X
X
X
The MAX3224E–MAX3227E/MAX3244E/MAX3245E fea-
ture an INVALID output that is enabled low when no
valid RS-232 voltage levels have been detected on all
receiver inputs. Because INVALID indicates the receiv-
er input’s condition, it is independent of FORCEON and
FORCEOFF states (Figures 3 and 4).
The MAX3224E–MAX3227E/MAX3244E/MAX3245E
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 trans-
mitter input for 30s, 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
(MAX3224E/
MAX3227E)
MAX3225E/
MAX3226E/
R_OUT
Active
Active
Active
Active
Active
Active
Active
Active
Active
AutoShutdown Plus Mode
(MAX3244E/
MAX3245E)
R_OUT
High-Z
High-Z
Active
Active
Active
Active
Active
Active
Active
(MAX3244E/
MAX3245E)
R2OUTB
Active
Active
Active
Active
Active
Active
Active
Active
Active