I am working on a Buck/Boost converter design which is based on Buck/Boost converter TPS63070RNMT. Below is the schematic design. All the selected components are as per the Section 9 of the datasheet.
USB connection is given priority in the design. If both USB & battery are connected to the board, PCB will be powered on by USB while battery gets charged.
The issue I am facing upon powering up is U6 not working as expected. Output is approx 1.2V and there is a lot of humming sound coming out of inductor. U6 is getting heat up very quickly. It is also affecting Original input waveformsand other sections. For example, USB input = 5V DC is superimposed with square wave. VBATT net on U1 also has some distortion in the form of sawtooth signal.
I am suspecting the inductor saturation issue. Did anyone face similar issue earlier?
Below is the layout of 3.3V supply section. It is as per the recommended layout mentioned in datasheet. Copper pouring added for VIN, Inductor nets and 3.3V. There is a 3.3V copper plane on Layer 3. On TOP layer, whole section is surrounded by Ground copper.
Need some inputs from the expert.
Thanks in advance.