about LM3409 spec

masaya hagiwara

Intellectual 740 points

Other Parts Discussed in Thread: LM3409

I have 3 requests

Please answer.

①Please show me LM3409's "Amplitude Dimming Using IADJ Pin" Linear Graph

②LM3409's Analog dimmig A/D input step?

③Please teach me Method of calculation about　Vin Low-frequency Ripple

over 11 years ago

0 Victor Chen_HK over 11 years ago

TI__Expert 5130 points

Hi,

For 1 and 2, you may refer to the figure I attached and pg10 of LM3409's data sheet.

Sorry I didn't quiet understand your 3rd question. What is your application and input/output voltage configuration?

Best regards,

Victor

0 masaya hagiwara over 11 years ago in reply to Victor Chen_HK

Intellectual 740 points

Victor san

Thank you for your reply

I want to Vadj 1V step ver.

③ is "Vin ripple　Method of calculation”

Best Regards

Masaya

0 Victor Chen_HK over 11 years ago in reply to masaya hagiwara

TI__Expert 5130 points

Hi Masaya-san,

To calculate Vin ripple, you may need to know the switching frequency fsw, input voltage Vin, output voltage Vout, inductor value L and the resistance of input source Rs. You can estimate the ripple by

(Vin-Vout)/L * Vout/Vin * 1/fsw

Thanks and best regards,

Victor

0 masaya hagiwara over 11 years ago

Intellectual 740 points

Victor san

Question regarding ②,

Is there a AD Converter between　CSN/CSP Amp. and Logic?

masaya

Power management

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about LM3409 spec