hi,
what is the pwm frequency of the TLC59711 board?
http://www.exp-tech.de/Shields/LED-Cont ... 59711.html
point is i would like to connect an arduino uno to the TLC board and connect its pwm outputs to 8 Motien led drivers to control 8 different high power leds (500mA)
Noice on the leds is an issue so i need a high pwm freqency.
i used pwm output 6 of the UNO and set it to max but that 62,5KHz is still way to low, somewhere in the MHz would be nice.
for pdf on motien see:
http://www.stadiumpower.co.uk/media/186 ... 30-600.pdf
Other reasons for using that board would be the many pwm outputs & 12 bit resolution.
thanks
TLC59711 board & max pwm frequency?
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- adafruit_support_rick
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Re: TLC59711 board & max pwm frequency?
I believe the internal PWM reference clock is 10MHz.
- crito
- Posts: 9
- Joined: Sat Mar 29, 2014 1:14 pm
Re: TLC59711 board & max pwm frequency?
hi,
>I believe the internal PWM reference clock is 10MHz.
i can see on the specs of the TLC59711 that the i2c transfer rate is (max) 10MHz but i can't find the pwm frequency.
http://www.ti.com/lit/ds/sbvs181/sbvs181.pdf
Can you let me know where that is mentioned?
Also with 12 bit you have 4096 steps, am i reading it correct that when you have the 10Mhz clock (0,1us) one period of the PWM is 4096 x 0,1us so 409,6us?
So basically not 10Mhz but 10Mhz/4096 = 2441Hz (2,4Khz)
>I believe the internal PWM reference clock is 10MHz.
i can see on the specs of the TLC59711 that the i2c transfer rate is (max) 10MHz but i can't find the pwm frequency.
http://www.ti.com/lit/ds/sbvs181/sbvs181.pdf
Can you let me know where that is mentioned?
Also with 12 bit you have 4096 steps, am i reading it correct that when you have the 10Mhz clock (0,1us) one period of the PWM is 4096 x 0,1us so 409,6us?
So basically not 10Mhz but 10Mhz/4096 = 2441Hz (2,4Khz)
- adafruit_support_bill
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Re: TLC59711 board & max pwm frequency?
The internal oscillator frequency 'Fosc' is 10 MHz. This is divided down by 2^16 to get 16 bit resolution on the PWM period. This gives you a PWM update frequency of ~153Hz.
- crito
- Posts: 9
- Joined: Sat Mar 29, 2014 1:14 pm
Re: TLC59711 board & max pwm frequency?
thanks,
>This gives you a PWM update frequency of ~153Hz.
ok, so if i look at the pwm signal with a scope i get a 153Hz pwm signal correct? (or with update frequency do you mean a change from 1 pwm setting to the next in case you change the duty cycle?)
a 153Hz pwm signal is to low for the application i have in mind.
What do you recomend to change the pwm to analog
or does adafruit have dac boards?
>This gives you a PWM update frequency of ~153Hz.
ok, so if i look at the pwm signal with a scope i get a 153Hz pwm signal correct? (or with update frequency do you mean a change from 1 pwm setting to the next in case you change the duty cycle?)
a 153Hz pwm signal is to low for the application i have in mind.
What do you recomend to change the pwm to analog
or does adafruit have dac boards?
- adafruit_support_bill
- Posts: 88093
- Joined: Sat Feb 07, 2009 10:11 am
Re: TLC59711 board & max pwm frequency?
I believe that is what you would see. Fromthe data sheet, it looke like the internal oscillator provides a 10MHz time base which is divided down into 2^16 increments. The 16 bit PWM setting determines how many of those increments are in the ON state to set the duty cycle.if i look at the pwm signal with a scope i get a 153Hz pwm signal correct?
We have a 12-bit DAC breakout: http://www.adafruit.com/products/935does adafruit have dac boards?
Please be positive and constructive with your questions and comments.