Hi,
I'm terribly sorry - but if you can't understand the above you are in a bit of a pickle.
I have to clarify a bit:
the brightness would increase with the amount of time that you hold low.
1) It´s
not that the brightness increases with time.
--> it´s the average brightness, that increases (from the snippet we don´t know if there is any electric filter involved)
2) it´s
not related to the LOW time (only)
--> it´s related to the duty cycle, thus it also is related to HIGH time.
Duty cycle is defined as : duty_cycle = active_time / (active_time + inactive_time)
Since in this application LOW means ACTIVE... it is valid to say
here: duty_cycle = LOW_time / (LOW_time + HIGH_time) = LOW_time / period_time
So the average brightness of the backlight will be the same for
* 30% duty cycle on 1kHz PWM
* 30% duty cycle on 10kHz PWM
* 30% duty cycle on any valid PWM frequency.
although the LOW_time at 10kHz PWM is
much less than at 1kHz PWM
At least this is true for the most (low_active) PWM applications.
I´m sure the full datasheet will clarify al in more detail.
the brightness will increase as the pwm increases
PWM means pulse width modulation
(it does not mean "duty cycle")
it is defined by
* LOW level (0V according snippet of datasheet)
* HIGH level (3.3V according .. datasheet)
* duty cycle (or HIGH time AND LOW time) (0% to 100% according datasheet)
* frequency (or period time) (1kHz to 10kHz according datasheet)
@EasyPeasy:
This is not meant to by picky. It is meant for the OP to learn the correct use of terminology.
For sure, if I or any other experienced designer reads your post .. we all know what you mean.
But this unexperienced member may be confused by sloppy wording.
Klaus