LM3445: Dimming range

K.Hamamoto

Part Number: LM3445

How much is the possible range of dimming controlled by this device if the triac dimmer is used?

As it's mentioned at the datasheet , the max duty is 96.5%. So that means the controllable dimming range is 0%~96.5%?

(This operation may be explained at datasheet at page 13 (7.3.9 dim decoder) I don't really understand those details very well.)

Best Regards,

Koji Hamamoto

over 4 years ago

0 Tuan Tran74 over 4 years ago

TI__Mastermind 18890 points

Hi Koji,

Dimming range can go up to 100% the specification you are looking at is for the internal ramp not the dimming range. The low end dimming range will depend on the triac that you use and the hold on current.

Thanks Tuan

0 K.Hamamoto over 4 years ago in reply to Tuan Tran74

Guru 12155 points

Hi Tuan-san,

Thank you for your reply.

>Dimming range can go up to 100% the specification you are looking at is for the internal ramp not the dimming range.

At the datasheet, it is mentioned as below.

Is it possible go up to 100% with triac dimmer? (100% means full brightness.)

Best Regards,

Koji Hamamoto

0 Tuan Tran74 over 4 years ago in reply to K.Hamamoto

TI__Mastermind 18890 points

Hi Koji-san,

Please see section 7.3.9 Dim Decoder. The part will do 0-100% dimming for most dimmer.

Thanks Tuan

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LM3445: Dimming range