# hspice to ltspice subcircuit

I am a novice with LTSpice, and I am attempting to use an HSpice model from Analog Devices. The component is a comparator (ADCMP601).

Unfortunately it appears that there is only an HSpice model, which I assumed had almost identical syntax to LTSpice.

My issue is that there are multiple instances of: "max=value min=value" (see example below) throughout the .SUBCKT file, which doesn't seem to be legal in LTSpice.

e0 18 0 17 0 4 max=0.3 min=-0.3
e1 20 0 19 0 1 max=0.3 min=-0.3


Is there a way to force max/min values using LTSpice syntax, in a similar manner to the original HSpice form? Or is it pointless trying to do this in LTSpice due to other potential syntax errors?

Thanks in advance!

I've attached the images of the circuit and error log.

Sine to square wave

Error log

## 1 Answer

Your model seems to consist of 2 voltage-controlled voltage sources. The e in e0 and e1 gives that away (in a spice netlist, e is a vcvs) I'm guessing that the max=0.3 min=-0.3 set the minimum and maximum output voltage.

Now let's see if there is a way to do the same but in a syntax that LTspice understands. Find a manual here it is, the interesting bit starts at page 113:

E. Voltage Dependent Voltage Source

yes that is what we need, now check if it will accept options to limit the minimum and maximum voltage. Hmm unfortunately there's nu such option. Bummer, this also explains why your model does not work !

Now there is also a BV (Arbitrary behavioral voltage source) source, see page 101. There are also some examples here. I think it is possible to replicate the model using the BV.

• Great, thanks for the help. I was considering changing everything to BV source and adding in value limits. Thanks again! – notsospicey Jun 20 '15 at 11:03
• My pleasure :-) Happy to help. – Bimpelrekkie Jun 20 '15 at 21:00