I have attached circuit using LT8604C. There is microcontroller-selectable MODE pin, to allow MCU to control when converter is in BURST vs FCM mode (FCM used during ADC operation to ensure fixed frequency, BURST used during lowest power modes).
The question is this, with output load current of ~10mA, the efficiency of the converter is only ~63%, Pout = ~18mW, Ploss = ~10mW.
Is there any modification to the circuit, either switching frequency or perhaps inductor selection that will allow that to be improved? I can drop the maximum designed output current to 20mA without any problems if that is a helpful tradeoff.
The ultimate target is with 5mA output current @ 1.8V, the total converter efficiency is around 80%. I am not sure if this is achievable with LT8604C though, please advise!
