The ePWM peripheral is used to perform a function that is mathematically equivalent to a digital-to-analog converter (DAC). As shown in Figure 1, the effective resolution for conventionally generated PWM is a function of PWM frequency (or period) and system clock frequency.

Figure 1. Resolution Calculations for Conventionally Generated PWM

If the required PWM operating frequency does not offer sufficient resolution in PWM mode, you may want to consider HRPWM. As an example of improved performance offered by HRPWM, Table 1 shows resolution in bits for various PWM frequencies. Table 1 values assume a MEP step size of 60 ps. See the device-specific datasheet for typical and maximum performance specifications for the MEP.