DC-DC converter requires 4 PWMs on the
primary side and 2 on the secondary. The first PWM for secondary side is taken from
EPWM6A. For flexibility sake, the second PWM is taken either from EPWM6B or EPWM7A. One
of them will become redundant, but it can give some design options for experimenting
during implementation. The related section on the control mother board is shown in Figure 3-6
Figure 3-6 Secondary PWM Source
A 0E resistor on R65 will select
EPWM6B as the source for 6th PWM (PWM F), whereas a 0E resistor on R63 will select
EPWM7A for the same.
It is not advisable to mount both R63 and R65 together, and better be kept
mutually exclusive to avoid malfunction or electrical damage to the pins if the
other pin were to be used accidentally.
Tip: The unused GPIO
pin between EPWM6B and EPWM7A could be used as a general purpose flag if required
and could be monitored on the open terminal side of R63 or R65.