TPS63030EVM-658: About PWM dimming

Sabrina-san,

Thank you for your support.
I will inform customers about the app note.

Let me ask about your advice
"the proposed circuitry in the app not is expected to work fine at PWM frequencies in the range of 100Hz to 200Hz."

1.Please tell me about the assumed PWM input range.
   And Is it possible to PWM dimming with the EN pin?
   It says you will not operate stably at 100 Hz to 200 Hz.
   Customer want to know this detailed reason.

2.Is there a problem with the schematic was sent to you?

Best Regards,
Yusuke/Japan Disty

Brigitte-san,

Thank you for you response.

1. You mention "It says you will not operate stably at 100 Hz to 200 Hz." What do you mean by this?

→ I wrote the answer of Sabrina-san.



    Customer want to know the PWM frequency that can be input to TPS63030.

 2. Why do you have a resistor divider connected to EN?
Sync/PS is differently connected than in the EVM, you should connect it with a 1 MOhm resistor to VIN.
 
→ Thank you for checking the schematic.
     Customer used TPS63030EVM-658 as the design starting point.
     Customer would like to study dimming by PWM from now on.
     For this reason, we have not yet determined the connection destination of the EN pin.
     I will report to the customer to change the connection of the Sync pin.　

VIN and VINA should be shorted.
R6 should be connected to VOUT not VIN.

→ The reason is,
     Customer did not have a zener diode with VZ = 2.5V.
     Therefore, VZ = 3.9 V is used as a substitute.
     Since Zener voltage is higher than VOUT, it is connected to VIN.
     Is this connection a problem?
     Could you give me your advice.

Best Regards,
Yusuke/Japan Disty

    

Brigitte-san,

Thank you for you kind support.
I will report your advice to customer.
And,I look forward to your reply about below.
"I need to clarify if PWM dimming is already tested with this part or not. Please expect my answer soon."

Best Regards,
Yusuke/Japan Disty