Datasheet

152
7734Q–AVR–02/12
AT90PWM81/161
The waveform frequency is defined by the following equation:
13.5.2.1 Four Ramp Mode
In Four Ramp mode, each time in a cycle has its own definition.
Figure 13-4. PSCr0 & PSCr1 basic waveforms in Four Ramp mode.
The input clock of PSCR is given by CLKPSC.
PSCOUTr0 and PSCOUTr1 signals are defined by On-Time 0, Dead-Time 0, On-Time 1 and
Dead-Time 1 values with:
On-Time 0 = OCRrRAH/L × 1/Fclkpsc
On-Time 1 = OCRrRBH/L × 1/Fclkpsc
Dead-Time 0 = (OCRrSAH/L + 2) × 1/Fclkpsc
Dead-Time 1 = (OCRrSBH/L + 2) × 1/Fclkpsc
Note: Minimal value for Dead-Time 0 and Dead-Time 1 = 2 × 1/Fclkpsc.
f
PSCn
1
PSCnCycle
------------------------------=
f
CLK_PSCn
OT0 OT1 DT0 DT1+++()
---------------------------------------------------------------------=
On-Time 0 On-Time 1
PSCOUTn0
PSCOUTn1
Dead-Time 1
Dead-Time 0
PSC Cycle
OCRnRB
OCRnSB
OCRnRA
OCRnSA
PSC Counter
00