Part Number:DRV8301
From what I can gather, the buck regulator block in the DRV8301 is the same as the TPS54160; the application notes and reference designs for the TPS54160 can/should be used for designing the buck circuit when using the DRV8301 (the DRV8301 datasheet has very little information on the buck regulator).
I'm attempting to analyze the buck regulator in a customer's DRV9301 design that is exhibiting poor regulation even at light load; approximately 3V droop at <200mA output (nominal input and output voltages are +28V and +15V, respectively). The observed switching frequency is approximately 50kHz (outside the specified range of 100kHz-2.5MHz), but this could be due to pulse skipping or the frequency shift divider. The RT_CLK pull-down resistor value (2k Ohms) also appears to be outside the normal range for this device, and when I replaced it with a 100k Ohm resistor (calculated based on other component in the circuit), the regulator functioned normally (stable regulation, low ripple, with a switching frequency of 1.2Mhz).
The question I am trying to answer is what effect would an RT_CLK resistor value of 2k Ohms have on the internal PLL or other functional blocks within the regulator?