Hi All,

I am using ADL5240 as a variable gain amplifier in DSA_IN/AMP_OUT configuration. I wanted to know what would happen if i dont put the 50 ohm load resistance at the load. (My output trace is very short) and I am driving a cap load of 32pF at 500Mhz

1. Will be circuit still be functional?

2. What is the reliability, i.e, how will it effect the life time of the IC. (What will be the lifetime of the IC if i use it in this configuration?)

Thanks and Regards,

Nishanth A B

  • +1
    •  Analog Employees 
    on Dec 4, 2019 6:39 PM


    The load impedance of a 32 pf capacitor at 500 Mhz is quite low, and not desirable for the amp to drive into.  If you need to drive such a load, it's probably best to first place a 6 dB resistive attenuator PAD in series with the load.