TPS61165: TPS61165 with exyernal PWM Dimming Network.

Mark Chen52

Part Number: TPS61165

Hi Expert,

I would like to know how to calculate or get resistor value of external PWM dimming network, datasheet has no to show the detail. could you help to know that?

thank you,

Mark

over 6 years ago

0 Sean Zhou over 6 years ago

TI__Mastermind 22745 points

Hi Mark,
That's very simple, use the KCL equation as below:
(I*Rset-VFB)/10k=(VFB-VPWM*Duty)/80k -> (I*Rset-0.2)/10k=(0.2-1.8*d)/80k -> I=1.8V*(1-d)/(8*Rset). Have a try.
Regards
Sean

0 Mark Chen52 over 6 years ago in reply to Sean Zhou

TI__Expert 8045 points

Hi Sean,

for the 10k 80k & 100k, are they fix value or not? I just confuse how to define the resistor value of 10k, 80k & 100k.

Mark

0 Sean Zhou over 6 years ago in reply to Mark Chen52

TI__Mastermind 22745 points

Hi Mark,

For 10k and 80k, you can change by yourself and use the equation as above to get the relationship between Duty and Iout. For 100k and 0.1uF this is a RC filter, you can change it depends on your PWM frequency.

Regards
Sean

0 Mark Chen52 over 6 years ago in reply to Sean Zhou

TI__Expert 8045 points

Thanks for quick response and solve my issue. Sean.

Best Regards,
Mark,

Power management

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TPS61165: TPS61165 with exyernal PWM Dimming Network.