Mar 18, 2014 #1 S sudhinpk Junior Member level 1 Joined Jan 27, 2014 Messages 18 Helped 0 Reputation 0 Reaction score 0 Trophy points 1 Activity points 105 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.
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.
Mar 18, 2014 #2 D.A.(Tony)Stewart Advanced Member level 7 Joined Sep 26, 2007 Messages 9,018 Helped 1,824 Reputation 3,647 Reaction score 2,205 Trophy points 1,413 Location Richmond Hill, ON, Canada Activity points 59,630 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.
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.
Mar 18, 2014 #3 S sudhinpk Junior Member level 1 Joined Jan 27, 2014 Messages 18 Helped 0 Reputation 0 Reaction score 0 Trophy points 1 Activity points 105 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.
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.
Mar 18, 2014 #4 D.A.(Tony)Stewart Advanced Member level 7 Joined Sep 26, 2007 Messages 9,018 Helped 1,824 Reputation 3,647 Reaction score 2,205 Trophy points 1,413 Location Richmond Hill, ON, Canada Activity points 59,630 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
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