Burning issue of LTC3600

Hello,

• is there no capacitance at VIn?
• What kind of capacitance is installed at VIN?
• 15V Vin are the max operating, has your customer tried a smaller input voltage for test purpose?
• You have only 1V margin to absmax of 16V
• How is the 15V input supplied? Step function with steep edges or slow ramp up? 
  /www.analog.com/.../an88f.pdf
• How is RUN and VIN voltage supplied and with which timing/delay?
• Is full current of 3A demand at start-up?

Check the circuit with smaller Vin first to see if part still fails

Dear MarkusHP

Thank you for your kind help.

Please refer below answers for your questions.

• is there no capacitance at VIn?
• What kind of capacitance is installed at VIN?

 - VIN is connected to +15VE of system power and connected like picture.

• 15V Vin are the max operating, has your customer tried a smaller input voltage for test purpose?
• You have only 1V margin to absmax of 16V

- They should get variable output power between 0.5V and 13.5V, so VIN should fix +15VE.

• How is the 15V input supplied? Step function with steep edges or slow ramp up? 
  /www.analog.com/.../an88f.pdf
• How is RUN and VIN voltage supplied and with which timing/delay?

- VIN is supplied at the same time  when system power is on.

- RUN is supplied when they are needed, not always. (Not the same time)

• Is full current of 3A demand at start-up

-  Spec. of their system  should supply 3A (Max. current of  LTC3600).

- They need max.3A current.

          Check the circuit with smaller Vin first to see if part still fails

- If output power is varied from 0.5V to 12V, up and down of output power is operated normally without any problem.

-  Issue is when output power is approched at about 13V, LTC3600 is malfunctio and device is burned.

I hope this help.

Regards,

Se-woong

Dear MarkusHP

Please confirm their answers in above messsage  and let me know your opinons.

My customer is still waiting your help.

Regards,

Se-woong

Dear MarkusHP

Would you let me know your statue about this issue?

My customer is still waiting your help.

Regards,

Se-woong

Have you ever simulated the schematic in LTSpice and check the power losses at higher Pout?

What is the temp of the parts with smaller VIN and still operating(related to output power)? have you ever checked that?

And I'm just a regular FAE like you, hence my customer prevent me to serve as full time source in EZ, sorry.

Dear MarkusHP

Thank you for your kind help.

And I understand your status.

Finally , my customer change the device from LTC3600 to LTC3263 with supporting more current.

Regards,

Se-woong

Dear MarkusHP

Thank you for your kind help.

And I understand your status.

Finally , my customer change the device from LTC3600 to LTC3263 with supporting more current.

Regards,

Se-woong