Screen brightness and PWM

[wibble]

Thanks for the datasheet. The chip isn't being used quite as the datasheet suggests, but the end result should be similar - the pwm signal is low pass filtered and used to control the current in a switch mode current source that's switching at ~1MHz. I don't know the pwm frequency and haven't done the calcs for the filter, but brightness ought to vary a lot less than if it were straight PWM of LEDs.