We are developing custom SDR hardware build around LMS7002M. We only need SISO, and because of board area constraint we would like to power it with single 1.8V power supply with internal LDOs for 1.25V and 1.4V.
I am not really sure how to connect low voltage pins. And there is no reference design with internal LDOs active, so I read LMS7002M_Power_Supply_Connection.pdf
On page 9 of the document:
- Low voltage power pins (1.25V and 1.4V) should be connected to a 1µF capacitor that
is connected to ground for stable internal LDO operation. Note, that for grouped pins,
that require external connection to one another (see Figure 1), only one capacitor is
needed per group;
So pins J5,K6 should be connected together with one capacitor, same goes for L5,K2 and F8,D6. But what about the other pins? Should I connect each one of the other pins to 1uF capacitor but not with the other pins? Or can I connect all the 1.25V pins together with only a few capacitors?