Pin Configuration : Serial Control Mode Operation HMC624ALP4E

Document created by analog-archivist Employee on Feb 23, 2016
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If we choose serial mode for HMC624ALP4E, Should D0-D5 and PUP1-2, SEROUT  be
N/C or  connect ground?


Kindly find the following configurations for serial control mode operation of

1. D0-D5
The floating digital inputs may cause leakage currents to flow from Vdd to Gnd.
In order to avoid from large leakage current, we recommend connecting all
parallel input pins (D0-D5) to either logic high (i.e. Vdd) or logic low (i.e.
Gnd) with pull up or down resistors (i.e. 100k) when the part HMC624ALP4E is
operated in serial control mode.

2. PUP1/2
If LE is set to logic low at power-up, the logic state of PUP1 and PUP2
determines the power-up state of the
part. We recommend connecting both PUP1 and PUP2 to logic low with pull down
resistor and keeping LE at logic low at power-up so that the part is powered up
at maximum attenuation setting (31.5 dB). The part will remain in maximum
attenuation setting until it is programmed for a defined state.

SEROUT port could be left floating or terminated with a high impedance load
(i.e. 100k) to Gnd.

Please also refer to the EZ discussion on: