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AD8367 - Maximum Output P1dB Point in 50Ohm configuration

Question asked by sugu89 on Mar 13, 2015
Latest reply on Nov 5, 2015 by jdobler



      We are planning to use AD8367 at our frequency 70+/-10MHz range for single ended I/P and O/P configuration in 50OHm impedance.


Our requirement is minimum gain of 40dB at our frequency and programmable gain range from 15dB to 40dB.


We discussed with your support team and they recommended to use 4:1 Rf Transformer part TC4-1W for single ended configuration with additional 2dB loss as stated in datasheet.


1) Can we use the same transformer part for input and output matching? We are unable to find the recommended output port impedance in you datasheet.


2) If we can use the same transformer at I/P and O/P for single ended 50Ohm configuration. Whether the Transformer center tap should be Dc coupled or AC coupled? Do you have any application circuit for Transformer matching for 50Ohm Impedance?


3) We have checked the OP1dB point for the Part : AD8367 (by using +5V supply) is +9dBm at 70MHz which is measured by 200Ohm Load impedance. After transformer matching as per the above, What will be the OP1dB point at 50Ohm load?


We have checked that Maximum Output Voltage Swing 3.5 Vp-p at RL= 200 Ω as per you datasheet specification. (If you have constant current source than reducing the O/P impedance will lower the O/P power to +3dBm)


Kindly confirm the same to proceed our design.



Sugumar K