Dear TI,
We have a design with LM26484SQ and using only the switched outputs. For 1.3V and 1.0V it works fine. Using FB resistors according to DS and 0.5uHy output inductor (LPS4414–501ML) also following the DS recommendation.
We also use LM26484SQ for 1.8V and for 3.3V we are also using 0.5uHy output inductor (LPS4414–501ML) and FB resistors according to DS. With no load, the outputs are 1.73V and 3.188V while connecting loads (~40mA for 1.8V and ~330mA for 3.3V) the voltage drops to 1.6V and 3V and I hear monotonic noise form the 3.3V output inductor. Input, Output and feedback capacitors are according to the datasheet as well.
Tomorrow, I'll try to replace the 3.3V inductor to 2.2uHy, as recommended in the datasheet, but still not clear why the voltage on the 1.8V is so low with and without load.
It would be great to debug it with TI support engineer.
Thanks,
IK