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Generating High Frquency PWM using PIC16F877A

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sudhinpk

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For my DC-DC Converter I need to generate a 50kHz PWM signal and I am using PIC16F877A. Is there any problem in generating such a high frquency using PIC16F877A's CCP Module? Plz... I need suggestions.
 

TABLE 8-3: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 20 MHz
TABLE 8-4: REGISTERS ASSOCIATED WITH CAPTURE, COMPARE AND TIMER1
PWM Frequency . . . . . 1.22 kHz 4.88 kHz 19.53 kHz 78.12kHz 156.3 kHz 208.3 kHz
Maximum Resolution (bits) 10 . . . . 10 . . . . . 10 . . . . . 8 . . . . . . 7 . . . . . . . 5.5

Previous pages define the Resolution, ratios and clock rates that set PWM.
 

SunnySkyguy said:
TABLE 8-3: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 20 MHz
TABLE 8-4: REGISTERS ASSOCIATED WITH CAPTURE, COMPARE AND TIMER1
PWM Frequency . . . . . 1.22 kHz 4.88 kHz 19.53 kHz 78.12kHz 156.3 kHz 208.3 kHz
Maximum Resolution (bits) 10 . . . . 10 . . . . . 10 . . . . . 8 . . . . . . 7 . . . . . . . 5.5

Previous pages define the Resolution, ratios and clock rates that set PWM.
Click to expand...

Thanks. But I can't understand about PWM resolution. Can you help me? I need to generate signal of 50 kHz and 70% duty cycle.
 

If 20MHz

78.12KHz with 8 bit resolution with PR2 = 0x3Fh =63d then 78.12* 63 = 4921

19.53 kHz with 10 bit resolution with PR2= 0xFFh = 255d then 19.53*255=4980 then

50 kHz assume PR2= 4950/50 = 99d =0x63h
 

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