Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State
  • Replies 1 reply
  • Subscribers 64 subscribers
  • Views 25 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

UCC27537: EMC issue due to oscillation on the input PWM and gate output (UCC27537DBVR)

Hani Jafari
Prodigy 10 points
Part Number: UCC27537

Tool/software:

Hello all,
In our projects, we plan to use UCC27537DBVR driver IC for the Mosfet BSC123N08. We used 5020YM IC driver before and now we would like to replace your products.
For a better understanding, I will attach the part of schematics which can give you an overview:
But we faced lots of difficulties in the input PWM comes from the MCU and out signal for Gate mosfet.
Input PWM from MCU:
Out from DRV to Gate:

 
While everything is very fine with the MI5020YM, we have lots of issue with the UCC27537DBVR  and it leads to EMC failure.
Can you please let me know if for the UCC27537DBVR  should I add any other parts on the schematics?
Best regards,
  • 0
    TI__Genius 10175 points

    Hey,

    Thank you for reaching out to TI with your questions regarding the UCC27537.

    With regards to the schematic, I have a couple of suggestions.

    1. We recommend placing an RC filter on the input pins placed closed to the gate driver. Typical ranges for the components are 0-100 Ohms and 10-100pF. This will help with the noise that is seen from the MCU on the input.

    2. For the ripple seen on the output, this is largely a result of the noise on the input as the driver is receiving mixed signals due to that input noise.

    3. Please ensure that C408 is placed as close to the driver as possible. You could also add a 100nF in parallel to C408 beside the driver for transient response.

    4. Adjusting the gate resistance R402 will also affect the rising and falling edges of the output by limiting output current.

    5. For EN enable, this could also be connected to the 18V supply rail as well.

    6. Layout is also important for noise. The gate drive path to the MOSFET should be as short as possible and have a wide trace. The high current paths such as VDD and GND should also have wide traces.

    Let me know if there are any further questions.

    Thank you,

    William Moore