LMH2832: Propagation delay or Group Delay information

Hello Alberto,

Could you elaborate more on your circuit needs and considerations?  While group delay would require your full circuit information and bench measurements, you can explore propagation delay in simulation:

1. Set up your circuit for a specific frequency

2. Do a phase response measurement/simulation

3. Knowing the operating frequency, evaluate the phase shift and convert to units of time

Best,

Alec

Hello Alec, 

thanks for your answer

the VGA is intended to be used in a baseband interface running at 350M, driving a quadrature modulator and a demodulator

All 4 devices have enough dynamics for our application, but a key parameter for the selection is the group delay (or propagation delay through the device) 

I'll try with the simulation, but any further data is more than welcome

Regarding the Group delay graph for LMH6517, I was wondering how to read it, considering that for frequencies below 350M and some attenuations, the group delay is negative 

thanks

Hello Alberto,

Thank you for expanding upon your design needs.  I can check with my team on any existing methods for measuring group delay, and provide an estimate of time required to do so.

Best,

Alec

Hi Alec, 

I manage to make an estimation using Tina Reference circuit

I'll try to to the same for the other devices 

If the simulations are reliable for this parameter this may be enough and your team can save the testing time :) 

Thanks

Alberto 

Hello Alberto,

I am glad to hear you were able to find value in the simulation.  Keep me updated on if you do not find the results to be useful or if you want to share your results for my team's opinion.

Best,

Alec

Hi Alec

here are some quick snapshot of the results

LMH2832

From Simulations: approx 210 ps  (Delta Vout-Vin)

 

 

LMH6881

From Simulations: approx 70 ps ? (Delta Vout-Vin)

 

LMH6521

From Simulations:  ?

LMH6517

No Model, from datasheet, approx 70 ps ?

Hello Alberto,

I will take a look at these results tomorrow.  Thank you for sharing them.

Best,

Alec