HMC624ALP4E : Settling time of 200ms, power-up

Document created by analog-archivist Employee on Feb 23, 2016
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The data-sheet of HMC624ALP4E states: "If the LE is set to logic HIGH at
power-up, the logic state of D0-D5 determines the power-up state of the part
per truth table. The attenuator latches in the desired power-up state
approximately 200 ms after power-up." But I am not sure what happens during the
time interval 0 to 200 ms after power-up if LE is high? I guess that HMC624
switch to the attenuation per truth table (for D0 - D5) within a few hundreds
of nano seconds and can be latched to a new state first after 200 ms. But I am
not sure what the 200 ms in the data-sheet means?


The controller circuitry requires some time to power up completely. The 200msec
spec is built in with some margin to ensure that the controller of all devices
are fully power up. During the time interval, the Dattn is in undefined state
as we do not know what is in the register.