JAJSIL9A February 2020 – July 2020 LM76005-Q1
PRODUCTION DATA
The default switching frequency of the LM76005-Q1 device is set at 400 kHz. If the RT is left open, the LM76005-Q1 switches at 400 kHz in CCM mode. Use Equation 13 to calculate the required value for RT to operate the LM76005-Q1 at different frequencies.
The result for 400 kHz is 99.57 kΩ.
The choice of switching frequency is a compromise between conversion efficiency and overall solution size. Lower switching frequency implies reduced switching losses and usually results in higher system efficiency. However, higher switching frequency allows for the use of smaller inductors and output capacitors, hence, a more compact design. When choosing operating frequency, the most important consideration is thermal limitations. This constraint typically dominates frequency selection. For the LM76005, the safe operating area is controlled by the thermal performance (RθJA=18.8 °C/W); see Figure 8-3.