This Design Idea leverages a LMC555 as a variable duty cycle (1 ms to 2 ms = 5% to 10%), constant frequency (20 ms = 50 Hz) PWM oscillator. Timing is ratiometric and therefore independent of V+ so no external voltage regulator is needed
| Authors | Stephen Woodward |
| Main Document | Article «Cheap and cheerful LMC555 RC PWM pulse generator» |
| Description | Figure 1 |
| File Format / Size | PDF / 14 Kb |
| Document Language | English |
Other Materials from the Main Document
- Article «Cheap and cheerful LMC555 RC PWM pulse generator»
- Figure 1 . This Design Idea leverages a LMC555 as a variable duty cycle (1 ms to 2 ms = 5% to 10%), constant frequency (20 ms = 50 Hz) PWM oscillator. Timing is ratiometric and therefore independent of V+ so no external voltage regulator is needed
- Figure 2 . The PWM oscillation cycle alternates between the Threshold pin for the duration of the 1 ms to 2 ms ON halfcycle is adjusted by R1, and the Trigger pin for the 18 ms to 19 ms OFF halfcycle. C2 > C1 to compensate for D1 forward drop