LM3450AEV230V30: Design without dimming feature

Miguel Camus

Part Number: LM3450AEV230V30
Other Parts Discussed in Thread: LM3409, LM3450

Hi all!

I am using the "AN-2150 LM3450A Evaluation Board" user guide, I want to implement similar design but without dimming feature. In the guide there is a second optocoupler with some more components for the triac dimming and I wonder if I could get rid of that part and how would be the circuit to run the driver continuously and without dimming feature.

Thanks in advance!

over 7 years ago

0 Irwin Nederbragt over 7 years ago

TI__Mastermind 28655 points

Hello Miguel,

Yes, you can get rid of the second opto that is driving the EN of the LM3409. Just tie the EN pin so it's always enabled. Other parts can be removed as well such as R8, R9, R56, C8, C9, C30 which are components for the damper for triac compatibility. The hold circuit can also be disabled as well

Regards,

0 Miguel Camus over 7 years ago in reply to Irwin Nederbragt

Prodigy 120 points

Hi Irwin,

Many thanks for your quick reply!

Do you mean that I can get rid of Qps, Rhld, Rsen, Chld, Csen as well?

I wanted to use the thermal protection, but I can do it using the Vadj pin I guess. I have done it similar in other designs.

Kind regards,

0 Irwin Nederbragt over 7 years ago in reply to Miguel Camus

TI__Mastermind 28655 points

Hello Miguel,

You cannot get rid of Qps since that is how the LM3450 is powered up at first turn on. Rhld and Chld aren't needed and you can also disable the input current measuring as well.

Regards,

0 Miguel Camus over 7 years ago in reply to Irwin Nederbragt

Prodigy 120 points

Hi Irwin,

Thanks for that! I will leave just the shottky diode for the return.

Regards,

Miguel

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LM3450AEV230V30: Design without dimming feature