inverter using dac output

[yasiralikhan]

i am trying to build an inverter 12 v to 220 v ac (500w). using microcontroller and 4-bit DAC. i got the stair case out put of 3.2 v p-to-p.now i want to make the output smooth. then amplify it.and then step it up to 220 v.
o am facing dificulty in refining the signal as well as amplifing it.
guys kindly help me on this.
regards

 

[betwixt]

If this is a power inverter to provide an AC power source, it will be very inefficient.
Consider using a more efficient high voltage DC generator then using the microcontroller to convert the DC to 'clean' AC.

Your problem with the present design is that with a 4-bit DAC you only get 16 steps in output voltage so the waveform will never be sinusoidal. The best you can do is pass the signal through a low pass filter to limit its slew rate so the sides of the step are less steep. Not a good solution but better than none.

Brian.

 

[FvM]

it will be very inefficient

You didn't tell about the intended "amplifier" type. A PWM power stage as a kind of class D amplifier can be efficient. If it follows
the classical triangle generator modulator approach, it could use a low-pass filtered 4-bit sine. Most designs are generating
the sine PWM in the digital domain from a look-up table, however.