Mlv Design Guide Page 9 Application Examples

CASE 1-AUTOMOTIVE TOUCH PANEL AND KEY/BUTTON PROTECTION PROTECTION NOTES To help protect displays and push buttons against ESD threats due to human contacts, overvoltage protection devices should be used to provide clamping, thereby limiting the ESD voltage and preventing control circuitry failure. In general, multilayer varistor (MLA) devices can be used. In this case, an MLA Automotive Series device may be selected. TVS Diode Arrays are another potential alternative. CASE 2 - AUTOMOTIVE CAN BUS PROTECTION NOTES Load dump event, switching transient from can be power windows, side mirrors and power door lock damaging to control multiple functions. Depending on surge rating, CAN bus or LIN bus DC line or data line. Key Parameters Application Condition Requirement for MLV Continuous Voltage Rating Typical working voltage at 5VDC or 12VDC Varistor voltage higher than 6VDC or 14VDC respectively Device size Customer may need compact design, SMD PCB mounting 0402 or 0603 based on board space limitation Energy and Peak Current IEC 61000-4-2 requirement at 8kV Contact Discharge All Littelfuse MLVs can meet the 8kV contact Discharge Clamping Voltage Application testing may be needed to determine exact clamping voltage needed Suggested Series Datasheet Link Link to MLA Automotive Key Parameters Application Condition Requirement for MLV Continuous Voltage Rating 12 VDC or 24VDC requirement based on system voltage Varistor voltage higher than 14VDC or 26VDC respectively Device size Customer may need compact design, SMD PCB mounting 1206 up to 2220 Energy and Peak Current Load Dump 10 Pulses Load Dump Energy up to 25 joules Clamping Voltage Application testing may be needed Suggested Series Datasheet Link AUML Series datasheet Note: This example is only for ESD threats; please refer to other example for other types of surges. 2016 Littelfuse Multilayer Varistors (MLVs) Design Guide www.littelfuse.com Surface Mount Multilayer Varistors (MLVs) Design Guide Application Examples 9

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