PIC18F2455_07 Datasheet, PDF (159/430 Pages) Microchip Technology – 28/40/44-Pin, High Performance, Enhanced Flash, USB Microcontrollers with nanoWatt Technology

PIC18F2455/2550/4455/4550
FIGURE 16-8:
PWM DIRECTION CHANGE
SIGNAL
Period⁽¹⁾
Period
P1A (Active-High)
P1B (Active-High)
DC
P1C (Active-High)
P1D (Active-High)
DC
(Note 2)
Note 1: The direction bit in the CCP1 Control register (CCP1CON<7>) is written any time during the PWM cycle.
2: When changing directions, the P1A and P1C signals switch before the end of the current PWM cycle at intervals
of 4 TOSC, 16 TOSC or 64 TOSC, depending on the Timer2 prescaler value. The modulated P1B and P1D signals
are inactive at this time.
FIGURE 16-9:
PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE
Forward Period
t1
Reverse Period
P1A⁽¹⁾
P1B⁽¹⁾
P1C⁽¹⁾
P1D⁽¹⁾
DC
External Switch C⁽¹⁾
External Switch D⁽¹⁾
Potential
Shoot-Through Current⁽¹⁾
Note 1: All signals are shown as active-high.
2: t_ON is the turn-on delay of power switch QC and its driver.
3: t_OFF is the turn-off delay of power switch QD and its driver.
DC
t_ON⁽²⁾
t_OFF⁽³⁾
t = t_OFF – t_ON^{(2, 3)}
© 2007 Microchip Technology Inc.
Preliminary
DS39632D-page 157