MAX3323EEUE Maxim Integrated, MAX3323EEUE Datasheet - Page 9

• Manufacturer Part Number: MAX3323EEUE
• Description: RS-232 Interface IC
• Manufacturer: Maxim Integrated
• Series: MAX3322E, MAX3323Er

Specifications of MAX3323EEUE

• Data Rate: 250 Kbps
• Operating Supply Voltage: 3 V to 5.5 V
• Supply Current: 1 mA
• Operating Temperature Range: - 40 C to + 85 C
• Function: Transceiver
• Number Of Drivers: 1
• Number Of I/os: 4
• Number Of Receivers: 1
• Propagation Delay Time Ns: 0.18 us, 0.7 us
• Shutdown: Yes

on the transmitter outputs and slightly reduces power
consumption. The values of C2, C3, and C4 can be
increased without changing C1’s value. However, do
not increase C1’s value without also increasing the val-
ues of C2, C3, and C4 to maintain the proper ratios (C1
to the other capacitors).
When using the minimum required capacitor values,
make sure the capacitor value does not degrade
excessively with temperature. If in doubt, use capaci-
tors with a larger nominal value. The capacitor’s equiv-
alent series resistance (ESR), which usually rises at low
temperatures, influences the amount of ripple on V+
and V-.
Table 2. Minimum Required Capacitor
Values
Figure 9. Multidrop Application
±15kV ESD-Protected, RS-232 Transceivers for
3.0 to 3.6
4.5 to 5.5
3.0 to 5.5
V
CC
(V)
UART
PC
_______________________________________________________________________________________
5kΩ
C1 (µF)
0.047
0.22
MAX3323E
0.1
CONTROL WITH UART
PERIPHERAL
C2, C3, C4 (µF)
0.33
0.1
1
5kΩ
MAX3323E
The MAX3323E connects to the RS-232 serial port of
computer peripherals such as a bar-code scanner,
video security controls, industrial multimeters, etc., and
allows multiple devices to share the same communica-
tion cable connected to a PC.
Figure 9 shows a PC UART transmitting to a single
receiver with a 5kΩ termination resistor while the other
receivers remain in a high-impedance state. When the
receiver inputs are high impedance, they remain active
and maintain receiving capability. This feature permits
the design of multidrop applications, which observe the
RS-232 interface standard.
Transmitters are enabled and disabled through
TXENABLE, allowing the sharing of a single bus line.
Transmitters are high impedance when disabled. The
host PC’s transmitter stays enabled at all times. Only
one peripheral transmitter remains enabled at any time.
If the host PC wants to communicate with another
peripheral, it first must tell the current peripheral to
deassert its transmitter.
CONTROL WITH UART
Multidrop Applications
PERIPHERAL
5kΩ
Multidrop Applications
MAX3323E
CONTROL WITH UART
PERIPHERAL
9