UCC25660: UCC256601 : LO, HO Pulse is not getting generated

Harshit Goel

Prodigy 10 points

Part Number: UCC25660

Tool/software:

Design Specs

Input voltage = 320V DC
Output Voltage= 48V DC, 5A

UCC25660DDBR IC is used and UCC25660X excel calculator has been used. Schematic has been attached.llc design.pdf

Operation
I have applied input voltage of 320V DC. After that i checked, at VCC(Pin 12) 12V is coming on the IC. 5v is generated at 5VP (Pin 8).

But LO (Pin11) and HO (Pin 15) are not generating pulses.

5 months ago

0 Manikanta Pallantla 5 months ago

TI__Genius 16155 points

Hi Harshit,

You shouldnt apply negative voltage at the BW/OTP pin. Depopulate both R21 and R6 resistors. Also, you shouldnt use UCC256601 incase if you are connecting HV pin DC input as this controller activates x-cap discharge function. Please replace the controller with UCC256602.

After you make these modification, measure BLK voltage. It needs to be higher than start threshold inorder to generate gate pulses.

Regards

Manikanta P

0 Harshit Goel 5 months ago in reply to Manikanta Pallantla

Prodigy 10 points

Hi Manikanta,
Thanks for your suggestion.I will implement this in my circuit. Please help me to get the IC UCC256602 as it is in pre-production.Can you please provide me samples ?
Thank You
Regards
Harshit

0 Manikanta Pallantla 5 months ago in reply to Harshit Goel

TI__Genius 16155 points

Hi Harshit,

You need to contact local FAE to get the samples. Let me know if you are not able to find one.

Regards

Manikanta P

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UCC25660: UCC256601 : LO, HO Pulse is not getting generated