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GENERATING A HIGH RESOLUTION SINEWAVE USING ST7 PWMART

Figure 2. Output at PWM0 pin and general calculation for finding sinewave frequency

10 PWM cycles each

Number Of Samples = 4

COUNTER=10

duty cycle

= ~50%

time

Vdd

maximum

duty cycle

= ~87%

average

duty cycle

= ~50%

minimum

duty cycle

= ~13%

duty cycle

= ~50%

one sinewave cycle

time

00

255

ARTARR=56

PWMDCR0 = Average Value =

155 (PWM duty cycle = ~50%)

PWMDCR0 = Average Value+75

PWMDCR0 = Average Value-75

Output at PWM0 pin

Output of RC circuit