Why when I measure the Idrive current during operational mode do I get higher
than the 20uA
as quoted in the maximum rating in the data sheet?
The conditions for Idrive current measurements in the data sheet are for a Vin
= 0V. This means that the output codes are all 0s. If the output codes are
toggling the current required to change the state of the SDO pin is increased
and the Idrive current is increased. The worst case current will be when the
conversion result is 101010… Cftl CN0247 can be viewed at the following
This gives the current draw on Idrive when a 10kHz input signal is applied and
a 1 MSPS sampling rate. The typical Idrive current is 409uA in this example.
The current drawn in a particular application will also depend on the
capacitive load on the SDO line.