pic24hj16gp304 Microchip Technology Inc., pic24hj16gp304 Datasheet - Page 131

• Manufacturer Part Number: pic24hj16gp304
• Description: High-performance, 16-bit Microcontrollers
• Manufacturer: Microchip Technology Inc.

EXAMPLE 13-1:
TABLE 13-1:
TABLE 13-2:
TABLE 13-3:
© 2007 Microchip Technology Inc.
Timer Prescaler Ratio
Period Register Value
Resolution (bits)
Timer Prescaler Ratio
Period Register Value
Resolution (bits)
Timer Prescaler Ratio
Period Register Value
Resolution (bits)
1.
2.
Find the Timer Period register value for a desired PWM frequency that is 52.08 kHz, where F
prescaler setting of 1:1.
Find the maximum resolution of the duty cycle that can be used with a 52.08 kHz frequency and a 32 MHz device clock rate:
PWM Frequency
PWM Frequency
PWM Frequency
T
PWM Period = 1/PWM Frequency = 1/52.08 kHz = 19.2 ms
PWM Period = (PR2 + 1) • T
19.2 ms
PR2
PWM Resolution
CY
PIC24HJ32GP202/204 and PIC24HJ16GP304
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 4 MIPS (F
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 16 MIPS (F
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MIPS (F
PWM PERIOD AND DUTY CYCLE CALCULATIONS
= 62.5 ns
= (PR2 + 1) • 62.5 ns • 1
= 306
= log
= (log
= 8.3 bits
30.5 Hz
FFFFh
FFFFh
FFFFh
10
7.6 Hz
76 Hz
10
(F
16
16
16
(16 MHz/52.08 kHz)/log
8
8
8
CY
CY
/F
• (Timer2 Prescale Value)
PWM
244 Hz
610 Hz
FFFFh
FFFFh
FFFFh
)/log
61 Hz
16
16
16
1
1
1
10
Preliminary
2) bits
1.22 Hz
122 Hz
488 Hz
7FFFh
7FFFh
7FFFh
10
15
15
15
2) bits
1
1
1
9.77 kHz
3.9 kHz
977 Hz
0FFFh
0FFFh
0FFFh
12
12
12
1
1
1
15.6 kHz
3.9 kHz
39 kHz
03FFh
03FFh
03FFh
10
10
10
1
1
1
CY
= 16 MHz and a Timer2
31.3 kHz
125 kHz
313 kHz
007Fh
007Fh
007Fh
CY
CY
CY
1
7
1
7
1
7
DS70289A-page 129
= 4 MHz)
= 16 MHz)
= 40 MHz)
1.25 MHz
125 kHz
500 kHz
001Fh
001Fh
001Fh
1
5
1
5
1
5