LTSPICE CIRCUIT SIMULATION FOR CALCULATION OF DELAY

G

Ghayathri

New Member

• Oct 12, 2020

• #1

As I was going through the forum about how to calculate delay in ltspice I came across this answer which said how to calculate delay for an inverter circuit. Could u please explain me how the spice directive commands work here and also what does {RE} refer to here.

 

Attachments

• Delay.JPG

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alec_t

Well-Known Member

Most Helpful Member

• Oct 13, 2020

• #2

Welcome to ETO!
{RE} is a parameter (aka a variable) whose value is specified by the .param directive.
The LTspice 'Help' describes the .meas directive, which provides a measurement of a property under defined circumstances.

 

G

Ghayathri

New Member

• Oct 13, 2020

• #3

How is the variable {RE} used here in delay calculation?

 

alec_t

Well-Known Member

Most Helpful Member

• Oct 13, 2020

• #4

Its value is 1, so it is being used to tell LTS to measure the time of occurrence of the first rising edge of V(in).

 

G

Ghayathri

New Member

• Oct 14, 2020

• #5

I have used the same .meas statements to calculate the propagation delay of my xor circuit but the value is high(0.04s but we are supposed to get in ps . Iam attaching the asc file for reference

 

Attachments

• fig1a_XOR.asc

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alec_t

Well-Known Member

Most Helpful Member

• Oct 14, 2020

• #6

Why do you have VIN connected to P3 source and to V1?

 

G

Ghayathri

New Member

• Oct 15, 2020

• #7

Sorry about the mistake in connection. Now i have corrected it and VIN is connected only to source of P3 as input and not connected to V1. I have attached the file for reference. Thank you

 

Attachments

• fig1a_XOR.asc

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G

Ghayathri

New Member

• Oct 21, 2020

• #8

Could anyone please help with how to calculate PDP (power delay product) using .meas statements in LTSPICEXV11