SLVSDV8 July 2017 TPS54424
In RT mode, a resistor (RT resistor) is connected between the RT/CLK pin and AGND. The switching frequency of the device is adjustable from 200 kHz to 1600 kHz by placing a maximum of 250 kΩ and minimum of 30.1 kΩ respectively. To determine the RT resistance for a given switching frequency, use Equation 9. To reduce the solution size one would set the switching frequency as high as possible, but tradeoffs of the supply efficiency and minimum controllable on-time should be considered. Equation 10 can be used to calculate the switching frequency for a given RT resistance.