ADL5902 - Aging question: 0.8dB drift within 4 months.

Hi,

We observe in our system about 0.8 dB (30mV) drift in power within 4 months.

We suspect that the failure is due to ADL5902.

At the input of the ADL5902 is a 15dB attenuator and at the output, ADC AD7791 is connected with reference of 2.5V from ADR431 to the ADC.

We built a look up table (calibration) per unit and is burn it to an internal EEPROM. 

The environment conditions are stable, the system temperature is between 25 to 35 deg C.

We use this setup for reading LTE signals with average power at input of our circuit of +10dBm and peak to Avg, up to 10dB .

(the power input of our circuit is about of avg. +10dBm max which means an avg. of -5dBm at the input of the ADL5902 due to 15dB attenuator).

Can Analog Devices supply aging data for ADL5902?

Can Analog Devices advise anything that we can do in our side to avoid or compensate for the aging issue?

Please advise.


Thanks,

Ilan


  • 0
    •  Analog Employees 
    on Feb 8, 2016 7:37 PM

    A shift of 0.8 dB seems much higher than anything we have observed. We have tested the long-term stability of ADL5902 up to 1000 hours and have seen movement of the order of 0.1 dB with most of that shift happening between 0 and 100 hours. The two plots below show how a batch of 8 devices moved over time. It's notable that the shift seems to be independent of input power level.

    Six devices form a cluster between +0.05 dna 0.1 dB, one device changes very little and one device moves by around 0.05 dB. So you cannot bank on every device shifting in the same direction. The data does however suggest that calibration (or maybe we should call it re-calibration) after 100 hours should give you more accurate results over the long term.

  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:22 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin