Design and implementation of architecture of Frequency trigger, Finite State Machine (FSM) for generating the PWM signal ,Pulse Width Modulation.
Input : clk,
Input : [11:0]sin amp
Input : switch0,fmhigh,fmlow.
Output: [1:0] pwm
Depending upon frequency high(fmhigh), frequency low(fmlow),frequency trigger will generate different waveforms. By using fsm we design Pwm model.
Architecture for the design specification
PWM is modulation technique used to encode a message into a pulsing signal. In PWM Ton denotes the one time and Toff denotes the off time of signal. Period is the sum of both on and off times and is calculated as shown below.
Ttotal =Ton +Toff
Duty cycle is calculated as on time to the period and duty is calculated as below
D=Ton /(Ton + Toff)
PWM Signal when used at a different duty cycles gives a varying voltage at the output. This method is used in various applications like:
- Switching regulators
- Led dimmers
- Analog signal generation
- Speed control of Motors
The out voltage is calculated by following equations
Vout = D*Vin
Vout =(Ton /Ttotal)*Vin