SPICE Model for AD8610 does not work

I'm using the AD8610 in a simple buffer application. AD8627 and ADA4622 are working as expected but in the prototype i am bound to the AD8610. See the part of the simulation below.

Followup: I tried also to eliminate R1, R2, C1 and C2, same result

AGND is just a virtual GND for the single supplied circuit and should have a voltage of 2.5V. The right side is a square voltage generator with the AGND as offset. The pp-voltage is 400mV and the AD8610 acts as buffer. Here is what the waves should look like (simulated with AD8627):

v(generator) and v(generator_out) are congruent... v(agnd) is 2.5V

Now the waves with original AD8610 spice model:

v(generator_out) is wrong.

I compared both models and found a way to make the circuit run, but I have no idea what the changed parameter does actually or where I can find it in the datasheet. Hope anyone can help me.

Left: AD8627 / right: AD8610

If I change V3 to 5 or something the circuit works correct. What is V2 and V3 for? Are the values correct?

Thanks in advance and best regards

Fabian

Parents
  • 0
    •  Analog Employees 
    on Jun 1, 2018 4:50 AM over 2 years ago

    Hi Fabian,

    V2 and V3 are part of the voltage limiting or clamping function of the model together with D1 and D2. Looking at the spice models of AD8627 and AD8610, there is some difference between the two in terms of how V2/V3/D1/D2 (clamping) are connected on the second stage and pole.

    I assumed you are putting 5V supply to your AVDD, is that correct? But I wonder why you need to put 100 ohms in series with AVDD? I tried to remove this resistor and AD8610 works fine without modifying the model. 

    Let me know if you have further questions.

    Regards,

    Arthur

Reply
  • 0
    •  Analog Employees 
    on Jun 1, 2018 4:50 AM over 2 years ago

    Hi Fabian,

    V2 and V3 are part of the voltage limiting or clamping function of the model together with D1 and D2. Looking at the spice models of AD8627 and AD8610, there is some difference between the two in terms of how V2/V3/D1/D2 (clamping) are connected on the second stage and pole.

    I assumed you are putting 5V supply to your AVDD, is that correct? But I wonder why you need to put 100 ohms in series with AVDD? I tried to remove this resistor and AD8610 works fine without modifying the model. 

    Let me know if you have further questions.

    Regards,

    Arthur

Children
No Data