Navigating Capacitor Choices in My Synchronous Buck Converter Design
Hello everyone. I am designing a synchronous buck converter using stm32f103c8t6 chip. I intend to use timer 1, i have setup my registers already and tested my output signals all seems fine with dead time included. I moved on to calculating the required inductance and output capacitance. I got 42uH for the inductance and the capacitance to be 73uF. I observed some designs done, and I did the calculations the capacitance falls in the same range, but they ended up using between 330uf and 470uf. I thought my calculation was wrong, but it seems it is not wrong. Can anyone point me in the right direction as to why almost all the time, the calculated output capacitor value is not used? my switching frequency is 35khz, my output voltage is 14.6, my input voltage is 21v, output current is 15A. The intended application is for an MPPt charge controller.
