ZHCSFE2A August 2016 – November 2017 LM5161-Q1
PRODUCTION DATA.
The ON-time of the LM5161-Q1 high-side FET is determined by the RON resistor and is inversely proportional to the input voltage (VIN). The inverse relationship with VIN results in a nearly constant frequency as VIN is varied. The ON-time can be calculated from Equation 3 with RON expressed in ohms.
To set a specific continuous conduction mode switching frequency (FSW expressed in Hz), the RON resistor is determined from Equation 4:
RON must be selected for a minimum on-time (at maximum VIN) greater than 150 ns for proper operation. This minimum ON-time requirement limits the maximum switching frequency of applications with relatively high VIN and low VOUT.