MAX13223EEUP+T Maxim Integrated Products, MAX13223EEUP+T Datasheet - Page 8

• Manufacturer Part Number: MAX13223EEUP+T
• Description: IC TXRX RS-232 2TX/2RX 20-TSSOP
• Manufacturer: Maxim Integrated Products
• Type: Transceiverr

Specifications of MAX13223EEUP+T

• Number Of Drivers/receivers: 2/2
• Protocol: RS232
• Voltage - Supply: 3 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 20-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

±70V Fault-Protected, 3.0V to 5.5V,
2Tx/2Rx RS-232 Transceiver
The MAX13223E achieves 1µA supply current with
Maxim’s AutoShutdown feature, which operates when
FORCEON is low and FORCEOFF is high. When the
device senses no valid signal levels on both receiver
inputs for > 30µs (typ), the onboard charge pump and
drivers are shut off, reducing supply current to 1µA.
This occurs if the RS-232 cable is disconnected or the
connected peripheral transmitters are turned off. The
device turns on again when a valid level is applied to
either RS-232 receiver input. As a result, the system
saves power. Table 2 summarizes the MAX13223E’s
operating modes. FORCEON and FORCEOFF override
Figure 5. Interface Under Control of PMU
Table 1. Receiver Control Truth Table
8
0
0
1
_______________________________________________________________________________________
Shutdown status is don’t care
MANAGEMENT
Shutdown (
Shutdown (AutoShutdown)
UNIT OR CPU
Active (AutoShutdown)
POWER-
Active (FORCEON), or
UART
OPERATION MODE
INVALID
FORCEOFF
FORCEON
MAX13223E
), or
AutoShutdown
High impedance
asserted low
Active and
R_OUT
Active
RS-232
AutoShutdown. When neither control is asserted, the IC
selects between these states automatically, based on
receiver input levels. Figure 6a shows the input levels
and Figure 6b shows the timing diagram for
AutoShutdown operation.
If direct software control is desired, INVALID can be
used to indicate a DTR or Ring indicator signal.
Connect FORCEOFF and FORCEON together to bypass
AutoShutdown; therefore, the line acts as a SHDN input.
Figures 6a and 6b. Trip Levels for Entering and Exiting
AutoShutdown
RECEIVER
a)
b)
VOLTAGE
OUTPUT
INVALID
INPUT
(V)
(V)
+2.7V
+0.3V
-0.3V
-2.7V
+2.7V
+0.3V
-0.3V
-2.7V
V
V
CC
V+
CC
V-
0
0
0
AutoShutdown, TRANSMITTER DISABLED,
t
TRANSMITTER ENABLED, INVALID HIGH
TRANSMITTER ENABLED, INVALID HIGH
INVL
Software-Controlled Shutdown
1μA SUPPLY CURRENT
INDETERMINATE
INDETERMINATE
t
INVH
INVALID
REGION
t
WU