PWM pulses and polish

Hello everybody,I try to make PWM controled leds with patch pulses and after every repeat they are smalller smaller and off.I hope to understand me,(like 0% -100%-0%,second 0%-80%-0%,third 0%-70%....etc >brightness control),i already have PIC software but the programmer is programed freq to 90 HZ and i see blinking between every step down I controlled led with transistor .I polish this blinking with big capacitor 1000uF paralell on led -i have looklike sine wave from PWM pulses .everiting is ok.But i think this with big capacitor is not good idea.It's too big.and chematic is not so inteligence I cant create what schematic to use ,to control led and polish pulses brom base of the transistor maybe.or other.I dont have idea what to try.Maybe sombody will have better answer?
p.s Soory for difficult explonation and bad EN.

You don't say the current and voltage. That would help. At the least add a small resistor in series with the cap to limit the charge current.

a schematic would help as well indicating number of LEDs, transistors connections etc.