Dear all
I want to design a power supply for a low power portable HF SSB rig with
maximum efficiency from a 12V battery
I will need +1.8V at around 200mA, +5V at low current, and +/-12V, with
the +12V at 1A unregulated. I thought of using a MAX1865 SMPS chip which
has multiple outputs with good efficiency. However I am conscious that
in a quiet analogue environment, the SMPS may be a problem with
switching noise. Is this a feasible idea? Should I use several separate
chips? What precautions should be taken? (I have read the Maxim app
notes on PCB layout and noise reduction, but I am not sure whether this
will be sufficient in this environment)

Thanks

Richard