Part Number: TPS54336A
Tool/software:
Dear All,
I built a DC/DC converter using the TPS54336A chip. The circuit design was developed using the WEBENCH tool based on the following specifications: input voltage range of 15-22V, output voltage of 14V, and output current of 1.28A. I simulated the circuit using both TINA and LT-Spice, and the results were promising.
During lab testing, I observed that it performs as expected when the controller operates in DCM. However, when I tried to increase the output current, the controller entered subharmonic oscillations, resulting in significant output voltage ripple, as can be seen in the pictures below.
Schematic:
Layout:
TINA:
AC Analysis:
Scope pictures:
(CH1, Vin, CH2 - Vout with offset, CH3 - SW node, CH4 - I_L)
Vin = 18V, Iout = 1.25A
Vin = 18V, Iout = 0.2A
Vin = 18V, Iout = 0.1A (DCM)
Thank you in advance.
