QIf we choose serial mode for HMC624ALP4E, Should D0-D5 and PUP1-2, SEROUT be
N/C or connect ground?
AKindly find the following configurations for serial control mode operation of
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.
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: