DN05045/D, based on NSIC2030B 1-10 V PWM Dimming for CCR Lighting Circuits

DN05045/D, Reference Design features a dimmable LED circuit using pulse width modulation (PWM). The dimming circuitry uses two comparators to adjust the brightness of the LEDs. Comparator A (U1-A) generates a Resistor-Capacitor (RC) wave that has a minimum of 1 Vdc and a maximum of 10 Vdc. Comparator B (U1-B) takes the generated RC wave (Vcompare) and compares it with the 1-10 Vdc input (Vdim) of the analog dimmer. When the 1-10 Vdc dimming is set to 1 Vdc or less, then the LEDs are off. When it is set to 10 Vdc, the LEDs will be completely on