RF Switches power-up sequencing


I am looking for an RF switch for my application and I have noticed that many of the switches with positive control voltages require power-up and power-down sequencing. This seems to be mentioned in the newer Analog Devices datasheets, but not in the older Hittite-style datasheets. Is this something that still needs to be updated in the Hittite datasheets, or is it safe to assume that if sequencing isn't mentioned, it is not required?

For example, I am considering HMC435AMS8GE, HMC241AQS16E and HMC345ALP3E. Can you confirm that they do not require sequencing?


  • +1
    •  Analog Employees 
    on Aug 5, 2019 5:21 PM

    For our RF switches including the parts mentioned above, the positive supply voltage must be powered up before control voltages. Otherwise, internal ESD protection diodes connected between control inputs to supply line could be forward biased and damaged. In such case, 1 kohm resistor in series with each control input can be used to limit forward bias current.