LCDA24 Semtech, LCDA24 Datasheet - Page 4

• Manufacturer Part Number: LCDA24
• Description: TRANSIENT SUPPRESSOR DIODE ARRAY,UNIDIRECTIONAL,24V V(RWM),SO
• Manufacturer: Semtech

Specifications of LCDA24

• Rohs Compliant: NO

Device Connection for Metallic Protection of High-
Speed Data Lines
The LCDA24C-1 is designed to protect high-speed data
lines from transient over-voltages which result from
lightning and ESD. The device is designed to protect
one line in common mode (Line-to-Ground) or one line
pair in metallic (Line-to-Line) mode. For metallic mode
protection, the input of line 1 is connected at pin 1 and
the output is connected at pin 4. Likewise, the input
of line 2 is connected at pin 2 and the output is con-
nected at pin 3. For common mode protection, ground
either pins 1 and 4 or pins 2 and 3. The ground
connection should be made directly to the ground
plane for best results.
ADSL Protection
A typical ADSL protection circuit is shown in Figure
3. A protection device with an operating voltage of
270 volts is connected on the line side of the circuit. A
high voltage device is used due to the presence of the
ring signal. Secondary IC side protection is achieved
with low voltage TVS devices. The LCDA24C-1 is
connected between to transmit line pairs. Since the
LCDA24C-1 has a working voltage of 24 volts, it may
be used on pairs with signal swings as high as +/-12
volts. The SD05C is used to protect the receive pairs.
The signal swings on these lines can be as high as +/-
5 volts.
PROTECTION PRODUCTS
PROTECTION PRODUCTS
Applications Information
2004 Semtech Corp.
Figure 3 - Typical ADSL Protection Circuit
4
Figure 1 - Connection for Differential Protection
Figure 2 - Connection for Common Mode
Line
In
Line
In
Line
In
Protection (Line-to-Ground)
2
1
2
1
(Line-to-Line)
4
3
4
3
LCDA24C-1
www.semtech.com
Line
Out
Line
Out
Line
Out