ZHCSJL9B April 2019 – April 2019 TPS566235
PRODUCTION DATA.
Out-Of-Audio™ (OOA) light-load mode is a unique control feature that keeps the switching frequency above audible frequency with minimum reduction in efficiency. It prevents audio noise generation from the output capacitors and inductor. During Out-of-Audio operation, the OOA control circuit monitors the states of both high-side and low-side MOSFETs and forces them switching if both MOSFETs are off for more than 32 μs. When both high-side and low-side MOSFETs are off for more than 32 μs during a light-load condition, the low side FET will discharge until reverse OC happens or output voltage drops to trigger the high-side FET on.
If the MODE pin is selected to operate in OOA mode, when the device works at light load, the minimum switching frequency is above 25 kHz which avoids the audible noise in the system.