hi sir,
my customer use LM3429 to drive a 13.3 inch panel, now customer use a external PWM to Dimming , now customer wants to know what's MAX Frequency of PMW connected the pin 7(ndim),Tks.
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hi sir,
my customer use LM3429 to drive a 13.3 inch panel, now customer use a external PWM to Dimming , now customer wants to know what's MAX Frequency of PMW connected the pin 7(ndim),Tks.
Hi Jerry,
Please read section 7.3.10 for PWM Dimming. The minimum ON time must be maintained and the equation is given as tpulse in equation (26). The frequency can by high but that relationship has to be maintained.
Thansk Tuan
hi sir,
thanks for your timely reply. now customer change the PWM to 23KHZ, duty cycle :6%-25%. but the panel will flash when the panel in the low brightness. could you please help to check what reason will result this issue,tks.
Hi Jerry,
The equation (26) on page 21 of the data sheet for Tpulse has to be met. So Tpulse has to be greater than that time. What is Vin, ILED, Vo, and L that you are using?
Thanks Tuan