VCVS in LTSPICE as a 1 bit Comparator

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I am using a VCVS in LTSPICE.

I am confused about the command in the Spiceline for using a Table.

I want to use the VCVS as a 1 bit Comparator instead of making a transistor based one.

What will adding the following spiceline for a VCVS in LTSpice do ?

table=(-0.5 0, 0 0, 1.0e-6 1, 0.5 1)

Will it set the output to 0 when the VCVS is input with -0.5, 0 output when it gets 0, 1 output when it gets 1u and one output when it gets 1?

Is this correct ?

Thanks.
 

Hi,

Why a VCVS? Why not some logic gate (s)?

Well, you have not explained what you want to compare but you have said one bit so I think you're referring to binary.

LTSPICE has a folder of components called DIGITAL. Inside the folder you have an XOR gate. Connecting a NOT gate at the output of the XOR gate gives an XNOR gate. You can successfully use this combination as a comparator for a one-bit input signal alongside a one-bit reference signal.
 

I believe the purpose and working of the table statement is well explained in SPICE and Ltspice manuals. See below the built-in help for Voltage Dependent Voltage Source


Yes, it's working as described in your question.
 

Some simulators added limit-values to the controlled sources
which could be handy, eliminating "blowups" from kV-range
voltages on devices fitted for only few-volt fidelity and sanity.
However this adds "sharp corners" where the transfer transitions
from controlled to clipped, which can itself be problematic
(usually want bounded and continuous derivatives; this is why
you often see tanh() used for things that "ought to be simpler".

But if it isn't a feature here then ....
 

Hello,

Thank you for your replies.

It is for an MDAC for a Pipeline ADC simulation. I need a 1 bit comparator for the 1.5 bit Pipeline ADC stage.
 

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