• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 493 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM5106: RT resistor is 10M ohm to get large deadtime, is there any risk?

Max Han
Intellectual 2260 points
Part Number: LM5106

Hi,

LM5106 is used in customer's application. customer needs a large deadtime.

now, RT resistor is 10M ohm, and deadtime is about 50us. from test result, this circuit works and can meet customer's requirement.

but the 10M ohm is out of range on below figure.

customer want to know: RT resistor is 10M ohm to get large deadtime, is there any risk?

  • 0
    TI__Mastermind 23215 points
    Hello Max,
    Thank you for supporting the LM5106 for your customer. I am an applications engineer supporting the LM5106 and will look to answer your questions.
    I see the datasheet curve you reference only shows data up to 150k Ohms RDT resistance, and the parameter table has test conditions for 100K Ohms. With a high resistance such as 10M the RDT pin will have very low programming current for the current mirror in the timer circuits. You should take extra care with the placement of RDT right next to the IC pins and on PCB layout avoid any switching signal traces close to the RDT pin or RDT resistor.
    It is also not clear what the tolerance of dead time will be with the larger program time values.
    Can you comment if the LM5106 is driving power devices with high dV/dt on the switching node? Or what the application circuit looks like?

    Regards
    Richard Herring