We are attempting to minimize the amount of current drawn by the LM46002 when operating in a standby mode (LM46002 is enabled, but minimal load). Vin = 12V, Vout = 5V.
In this mode, see about 160 uA drawn from 12V input. Feedback resistors were originally set to 100k (top) and 25k (bottom), 1% tolerance. To reduce the current in this path, changed these by a factor of 10 (1M/250K, 1% tol). Current draw on 12V input only changed 10 uA. This should change output load current by 36 uA and expected this to change the input current by at least 15 uA, and maybe as high as 20 uA depending on efficiency).
Also tried increasing resistors on the EN input. These were 330k each (dividing 12V input in half). Changed to 1M each, but the output became unstable, so settled on 800k each. But see no change in 12V current draw. Note that there is also a 2N7002 nFET connected to the EN pin to pull the node down when the system needs to disable the LM46002.
Any explanation why the input current is not changing as expected?
