MAX563CWN-T Maxim Integrated, MAX563CWN-T Datasheet - Page 4

• Manufacturer Part Number: MAX563CWN-T
• Description: RS-232 Interface IC
• Manufacturer: Maxim Integrated
• Series: MAX563r

Specifications of MAX563CWN-T

• Data Rate: 116 Kbps
• Operating Supply Voltage: 3.3 V
• Supply Current: 8 mA
• Operating Temperature Range: 0 C to + 70 C
• Mounting Style: SMD/SMT
• Function: Transceiver
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Number Of Drivers: 2
• Number Of I/os: 8
• Number Of Receivers: 2
• Propagation Delay Time Ns: 1 us, 3.5 us
• Shutdown: Yes

The MAX563 consists of three sections: charge-pump
voltage converters, transmitters (drivers), and
receivers. Both the transmitters and the receivers are
inverting.
Two charge pumps either invert or double the incoming
V
ters. The first charge pump uses capacitor C1 to
double V
reservoir capacitor. The second charge pump uses
capacitor C2 to invert V+; this negative voltage is
stored on the V- capacitor.
When SHDN is low, the charge pumps are turned off,
V+ is pulled down to V
rises to GND.
It is possible to draw some power from the V+ and V-
pins for external use. However, doing so diminishes the
charge-pump output voltages and reduces noise mar-
gins, so it is not recommended.
+3.3V-Powered, EIA/TIA-562 Dual Transceiver
with Receivers Active in Shutdown
4
______________________________________________________________Pin Description
_______________Detailed Description
CC
_______________________________________________________________________________________
to generate the voltages required by the transmit-
+3V to ±6V, Dual Charge-Pump Voltage
10, 13
11, 12
8, 15
9, 14
PIN
16
17
18
1
2
3
4
5
6
7
CC
; the resulting voltage is stored on the V+
R2
T2
R2
T2
OUT
OUT
NAME
SHDN
IN
IN
GND
C1+
C2+
V
C1-
C2-
EN
V+
V-
CC
, T1
, R1
, R1
, T1
CC
OUT
IN
IN
OUT
by a 1kΩ resistor, and V-
Receiver enable. Connect EN to GND to enable receivers, and take EN high to disable receivers.
Positive terminal of positive charge-pump capacitor.
+2V
V
Negative terminal of positive charge-pump capacitor.
Positive terminal of inverting charge-pump capacitor.
Negative terminal of inverting charge-pump capacitor.
-2V
GND when SHDN is low.
EIA/TIA-562 voltage-level transmitter outputs. These outputs are disabled (Hi-Z) when
SHDN is low.
EIA/TIA-562 and EIA/TIA-232 voltage-level receiver inputs.
CMOS receiver outputs. These outputs are active regardless of the state of SHDN. They
are enabled when EN is low, and disabled (Hi-Z) when EN is high.
CMOS driver inputs.
Ground.
+3.0V to +3.6V supply voltage.
Shutdown control. Connect to GND to shut down the charge pumps and the transmitters.
Take high to turn on the charge pumps and to enable the transmitters.
CC
CC
CC
when SHDN is low.
voltage generated by the inverting charge pump. The voltage on V- collapses to
voltage generated by the positive charge pump. The voltage on V+ collapses to
Converter
The MAX563’s drivers are inverting level translators that
convert +3V logic inputs to EIA/TIA-562 voltage levels.
With a VCC supply of only 3.0V, the driver outputs
deliver the EIA/TIA-562 ±3.7V minimum specification
under worst-case conditions—when both transmitters
are loaded with 3kΩ receivers (either EIA/TIA-232 or
EIA/TIA-562).
The transmitters are fast: the guaranteed data rate with
standard loads is 116kbps, which is the highest rate
commonly used by PC-to-PC communication software,
such as LapLink. The highest practical data rate may
be reduced if the other communicating device (RS-562
or RS-232) is not as fast, or if the cables present an
excessive capacitive load (>1000pF). Each transmitter
is designed to drive a single receiver; transmitters can
be paralleled to drive multiple receivers.
When SHDN is low, the driver outputs are turned off.
Their output leakage currents are less than 10µA when
pulled to GND or when driven to ±15V. This enables
two transmitters to be connected to the same line, pro-
vided that one of them is always disabled by taking
SHDN low.
FUNCTION
EIA/TIA-562 Transmitters