I'm trying to simulate the ADL5536 Gain Block in LTspice. A link to the datasheet can be shown below:


Analog Devices doesn't have a SPICE model for it, only the S-model parameters, but I think I found a rough workaround, and I wanted to ask here whether it was feasible or not.

The gain was presented as roughly 20.1 dB, round it to 20 dB, and I was thinking of using an ideal op-amp to simulate the gain ideally as shown below:


simulate this circuit – Schematic created using CircuitLab

For a rough gain estimate, assuming same impedances, modeling it as an ideal non-inverting op-amp should lead to the 20 dB gain based on calculating the voltage gain in decibels. Does this seem correct based on my understanding, or am I missing something?

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    \$\begingroup\$ If your concern is the gain, only (and, maybe, a rough approximation to its gain-bandwidth), then yes. You may even be able to set the output resistance (impedance) to come close to the device. Otherwise, ideal does not equal practice. \$\endgroup\$ – a concerned citizen Dec 19 '17 at 7:11

The opamp model in lt spice is an ideal model which has the following properties:

  1. Infinite voltage gain
  2. Infinite input impedance
  3. Zero output impedance
  4. Zero input offset voltage.

which you have to be careful because the op amp can source infinite amounts of current or voltage. The model also has 1 pole 'filter' on the output to limit the bandwidth, and open loop gain.

These can be set by changing the Aol (open loop gain) parameter and GBW (bandwidth) parameter.


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