Quote Originally Posted by batee
Has anyone looked into using a DDS IC like the AD9833 for an inverter application? What were the results? How did you achieve PWM from the analog output?

Bryan A. Thompson
[email protected]

I haven't seen the AD9833 datasheet. In analog it is very simple to make
PWM. What U need is to make a reference sinewave oscillator. This U can find
from Opamps Application note of National Semiconductors. Oscillator uses
weign bridge and JFET to stabilise amplitude. Then U need a trinagular wave
of " carrier " frequency i.e. at which frequency U want PWM. U feed the
triangualar wave and sinewave to good comparator and Uget the PWM in output. If U want -ve side PWM also then U use one inverter for sinewave
and feed that to another comparator. And U get the -ve half signal for pwm.
There is interesting article about this on
url:http://www.drbrushless.com/