I do not understand the behaviour of the LMX2531LQ1570E RF synthesiser with the Chip Enable (CE) pin low. This seems to be inconsistent between different devices. Holding CE low, then applying VCC on one device we see zero current, indicating the part is powered down as expected. On another part we see about 20mA of current, which we would not expect (with CE low). The programming data has not been sent, in both cases. Why are we seeing this inconsistency between parts?
With the issues using CE we have tried another way of powering down by programming register R5 once to reset the part and once to set the bits for the circuits in the chip to power down. We are seeing about 2mA of unexplained current in this situation. Is there anything else that we are missing to get the part to fully power down?
