Dynamic current measurement principle
UM2243
24/41
UM2243 Rev 2
10
Dynamic current measurement principle
The dynamic measurement mode allows measurement of fluctuating currents from 100 nA
to 50 mA with an accuracy in the range of 2%.
Measurement acquisitions are performed using three 12-bit ADCs working in parallel at
3.2 Msamples/s each and with 100 kHz bandwidth on the analog circuit path. This high
sampling rate allows fast current variations (transient current, peak current activities on
target board side) to be caught.
The dynamic current measurement principle is based on the shunt method as for the static
measurement. Nevertheless, a specific and complex architecture performs dynamic
measurement with a 100 kHz bandwidth covering the wide current measurement range of
about 110 dB (from 100 nA to 50 mA) by keeping the output voltage stable.
The dynamic current circuitry has built-in overcurrent protection that operates from 59 mA.
Therefore some transient current spikes of up to 75 mA and less than few milliseconds are
allowed.
Figure 17. Dynamic current block diagram
(a)
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a. Patent pending
