Other Parts Discussed in Thread: LMR38015
Tool/software:
Hello all,
I am working on a design with the LMR38015 but cannot seem to get the switching frequency above 1.6 MHz in WEBench. My settings are as follows:
VIN: 13-60 V
VOUT: 12 V
IOUT: 1 A
Here is the link to the WEBENCH design
webench.ti.com/.../SDP.cgi
According to the datasheet:
fsw < VOUT / (TON_MIN x VIN_MAX) = 12 V / (80 ns x 60 V) = 2.5 MHz
D_MIN = TON_MIN x fsw = 80 ns x 2.1 MHz = 16.8 % (at 2.1 MHz switching frequency)
The WEBENCH simulation calculates a duty cycle of 20.37 %
I do not understand why the WEBENCH simulation cannot go above 1.6 MHz. Is there something I missed in the datasheet? Changing the input voltage range to 50 V increases the maximum switching frequency to 2.2 MHz
