MAX3223ECAP+ Maxim Integrated Products, MAX3223ECAP+ Datasheet - Page 9

• Manufacturer Part Number: MAX3223ECAP+
• Description: IC TXRX RS232 250KBPS SD 20SSOP
• Manufacturer: Maxim Integrated Products
• Type: Transceiverr

Specifications of MAX3223ECAP+

• Number Of Drivers/receivers: 2/2
• Protocol: RS232
• Voltage - Supply: 3 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 20-SSOP
• Propagation Delay Time Ns: 0.15 us
• Operating Supply Voltage: 3 V to 5.5 V
• Supply Current: 0.3 mA
• Operating Temperature Range: 0 C to + 70 C
• Data Rate: 250 Kbps
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 1. Output Control Truth Table
±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,
X = Don’t Care
Figure 3a. MAX32_ _E Entering 1µA Supply Mode via
AutoShutdown
A mouse or other system with AutoShutdown may need
time to wake up. Figure 4 shows a circuit that forces
the transmitters on for 100ms, allowing enough time for
the other system to realize that the MAX3221E/
MAX3223E/ MAX3243E are awake. If the other system
transmits valid RS-232 signals within that time, the RS-
232 ports on both systems remain enabled.
When shut down, the device’s charge pumps are off,
V+ is pulled to V
transmitter outputs are high impedance. The time
required to exit shutdown is typically 100µs (Figure 5b).
If direct software control is desired, INVALID can be
used to indicate DTR or Ring Indicator signal. Connect
FORCEOFF and FORCEON together to disable Auto-
Shutdown so the line acts like a SHDN input.
Shutdown
(Forced Off)
Normal Operation
(Forced On)
Normal Operation
(AutoShutdown)
Shutdown
(AutoShutdown)
+0.3V
-0.3V
R_IN
OPERATION
* TRANSMITTERS ARE DISABLED, REDUCING SUPPLY CURRENT TO 1μA IF
ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR AT LEAST 30μs.
STATUS
Software-Controlled Shutdown
RS-232 Transceivers with AutoShutdown
_______________________________________________________________________________________
CC
FORCEON
, V- is pulled to ground, and the
X
X
1
1
0
0
0
0
FORCEOFF
COUNTER
30μs
0
0
1
1
1
1
1
1
R
AND TRANSMITTERS
POWER SUPPLY
INVALID
TO MAX32_ _E
(MAX3221E/
MAX3223E)
EN
0
1
0
1
0
1
0
1
RECEIVER
LEVEL
VALID
Yes
Yes
As with all Maxim devices, ESD-protection structures are
incorporated on all pins to protect against electrostatic
discharges encountered during handling and assembly.
The driver outputs and receiver inputs of the
MAX3221E/MAX3223E/MAX3243E have extra protection
against static electricity. Maxim’s engineers have devel-
oped state-of-the-art structures to protect these pins
against ESD of ±15kV without damage. The ESD struc-
tures withstand high ESD in all states: normal operation,
shutdown, and powered down. After an ESD event,
Maxim’s E versions keep working without latchup,
whereas competing RS-232 products can latch and
must be powered down to remove latchup. See Table 4.
Figure 3b. MAX32_ _E with Transmitters Enabled Using
AutoShutdown
No
No
X
X
X
X
+2.7V
-2.7V
R_IN
*TRANSMITTERS ARE ENABLED IF:
ANY RECEIVER INPUT IS GREATER THAN +2.7V OR LESS THAN -2.7V.
ANY RECEIVER INPUT HAS BEEN BETWEEN +0.3V AND -0.3V FOR LESS THAN 30μs.
T_OUT
High-Z
High-Z
High-Z
High-Z
Active
Active
Active
Active
(MAX3221E/
MAX3223E)
R_OUT
High-Z
High-Z
High-Z
High-Z
Active
Active
Active
Active
±15kV ESD Protection
(MAX3243E)
R_OUT
High-Z
High-Z
Active
Active
Active
Active
Active
Active
COUNTER
30μs
R
POWER SUPPLY
(MAX3243E)
INVALID
TO MAX32_ _E
R2OUTB
Active
Active
Active
Active
Active
Active
Active
Active
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