TYPICAL CLAMPING VOLTAGE VS PEAK PULSE CURRENT FOR PLC497
16
V
C
- Clamping Voltage - Volts
12
8
4
0
0
2
4
6
8
10
12
14
16
18
I
PP
- Peak Pulse Current - Amps
05100.R6 2/07
3
www.protekdevices.com
PLC497
APPLICATION NOTE
The PLC497 is an ultra low capacitance, bidirectional array that is designed to protect I/O or high speed data lines from the damaging effects of ESD
or EFT. This product has a surge capability of 250 Watts P
PP
per line for an 8/20µs wave form and offers ESD protection > 40kV.
DIFFERENTIAL-MODE CONFIGURATION (Figure 1)
The PLC497 is designed to protect one unidirectional line. Figure 1 shows a typical differential-mode (line to line) I/O port protection circuit application.
To achieve bidirectional protection, two PLC497 units are placed in parallel with opposing polarities within the circuit layout.
Circuit connectivity is as follows:
✔
Pins 1 and 2 of each device connected to datalines
✔
Pin 3 is not connected
COMMON-MODE CONFIGURATION (Figure 2)
The PLC497 can provide protection for sensor circuit applications. Figure 2 is a typical common-mode (line to ground) sensor circuit application. To
achieve bidirectional protection in this application, a second pair of TVS devices is added in parallel with opposing polarities where pins 2 are
connected to the line, pins 1 connected to ground and pins 3 unconnected.
Circuit connectivity is as follows:
✔
Pins 1 each device connected to datalines
✔
Pins 2 each device connected to ground
✔
Pin 3 is not connected
Figure 1. Typical Differential-Mode i/o Port Protection Circuit
LINE 1 IN
LINE 1 OUT
CIRCUIT BOARD LAYOUT RECOMMENDATIONS
1
2
Circuit board layout is critical for Electromagnetic
Compatibility (EMC) protection. The following guidelines
are recommended:
✔
The protection device should be placed near the
input terminals or connectors, the device will divert
the transient current immediately before it can be
SPECIFICATIONS: ProTek reserves the right to change the electrical and or mechanical characteristics described herein without notice (except JEDEC).
DESIGN CHANGES: ProTek reserves the right to discontinue product lines without notice, and that the final judgement concerning selection and specifications is
the buyer’s and that in furnishing engineering and technical assistance, ProTek assumes no responsibility with respect to the selection or specifications of such