Pulse-width distortion (PWD) arises from mismatch in the HSS’s ON and OFF delay times and low-high/high-low propagation delay. In Figure 3-2, the various timing parameters that need to be considered when implementing a PWM scheme with a TI high-side switch is illustrated. The timing parameters in this diagram are correlated closely to the parameters specified in the "Switching Characteristics" section of the device data sheet. In Figure 3-3, an example excerpt of the switching characterstics can be seen.

The pulse-width distortion due to propagation-delay effects is defined asIf the high-side switch data sheet specifies t_d(match), using this parameter is preferable to calculate total distortion as it removes any uncertainty of correlation between slew rate and out. When rise and fall times are much smaller than the pulse width, slew-rate effects can be ignored and total pulse-width distortion may be approximated as:In the case the data sheet does not specify t_d(match) we can obtain more precision by using:Where V_vs is the high-side supply voltage, and SR_ON / SR_OFF are the device turn-on/turn-off slew rates. Note that these specifications are worst-case and are specified at a specific supply voltage and load current. The use of the worst-case parameters will allow us to build a robust design that will work under a wide arrange of ambient conditions.