thobie
Newbie level 2
Hi,
I'm looking through the "Programmable Logic Controller (PLC) I/O Module Front-End Controller with Tiva C Series ARM® Cortex™-M4 MCU" (**broken link removed** / page 32) design, and the surge protection / hot plug part having the next schematic:
It has the R126 1MOhm parallel resistor next to the D16 varistor, C94 cap and L8 noise filter. What is the purpose of this (high value) resistor?
1. uncharge the C94 cap?
2. serve as a current path when the power plug is unconnected (left over energy in L8)?
3. some purpose in ESD protection?
4. has only meaning when the varistor is not mounted (DNP-component)?
5. something else..?
I'm looking through the "Programmable Logic Controller (PLC) I/O Module Front-End Controller with Tiva C Series ARM® Cortex™-M4 MCU" (**broken link removed** / page 32) design, and the surge protection / hot plug part having the next schematic:
It has the R126 1MOhm parallel resistor next to the D16 varistor, C94 cap and L8 noise filter. What is the purpose of this (high value) resistor?
1. uncharge the C94 cap?
2. serve as a current path when the power plug is unconnected (left over energy in L8)?
3. some purpose in ESD protection?
4. has only meaning when the varistor is not mounted (DNP-component)?
5. something else..?