25kHz PWM signal to analog voltage (DC) using low-pass filter: Weird output

Other Hardware General Electronics
17

Your function generator for PWM control ... is it set to the correct PWM mode so that the signal is 0 to +5V with 0-100% duty? Or is it -5V to 0 for 0-50% duty and 0 to +5V from 50-100% duty?