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Current sensing wakeup time

Question asked by wallis.mark.001 Employee on May 6, 2013
Latest reply on May 7, 2013 by Boimond.Anthony
Hi, I have an application where I am trying to measure accurately the inductor current in a buck converter using a TSC103 current sense amplifier. Unfortunately when the converter is in pulse frequency modulation mode, the current through the inductor falls to zero, and with ringing it can even go negative. In the Spice simulation I see a delay in the output of the amplifier when the converter switch is closed again (see attached file showing the sense resistor current and the sense amplifier output voltage).
Is this the result of a so-called waking-up effect? Is it real or an artefact of the simulation model?
Assuming it is real, can anything be done to avoid it? Do any of the current sense amplifiers support negative Vsense?