33
ATtiny15L
1187H–AVR–09/07
The frequency of the PWM will be Timer Clock Frequency divided by OCR1B value + 1.
The exact duty-cycle of the non-inverted PWM output is:
Where:
T
T1
is the period of the selected Timer/Counter1 Clock Source.
T
PCK
is the period of the PCK Clock (39.1 ns).
Table 14. Timer/Counter1 Clock Prescale Select
Clock Selection OCR1B PWM Frequency
CK 159 10 kHz
PCK/8 159 20 kHz
PCK/4 213 30 kHz
PCK/4 159 40 kHz
PCK/2 255 50 kHz
PCK/2 213 60 kHz
PCK/2 181 70 kHz
PCK/2 159 80 kHz
PCK/2 141 90 kHz
PCK 255 100 kHz
PCK 231 110 kHz
PCK 213 120 kHz
PCK 195 130 kHz
PCK 181 140 kHz
PCK 169 150 kHz
OCR1A +1()T
T1
× T
PCK
–
OCR1B +1()T
T1
×
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