Touch Screen Controller

Circuit Protection of Keypad / Touch Screen Controller



Design Notes:

Protection Application:
The periphery of the touch panel could be an entry way for ESD.
Solution Description:
The example shown at the left contains four lines for demonstration purposes. The actual number will vary by application. Discrete multilayer varistors are used to provide board layout flexibility.
Companion Solutions:
Other solutions within the LF portfolio exist in addition to these recommendations. For example, Diode arrays with different channel counts (2 – 14 lines) can be used to match the actual conditions.
Regulatory Issues:
The IEC 61000-4-2 will be the most appropriate standard that applies for these circuits. It supplies a test method for verifying that the end product is not susceptible to ESD events.
Unique Features:
Does not apply.
Application Warnings:
Does not apply.

Solutions

Solutions