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Design Languages >> Verilog-AMS >> How to write a time amplifier?
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Message started by 5gougou on Apr 18^th, 2010, 7:44pm

Title: How to write a time amplifier?
Post by 5gougou on Apr 18^th, 2010, 7:44pm

How to write a 2x time amplifier with Verilog-A?
This is a model with two input signals with a time interval of T1, and two outputs with time interval 2*T1.

Does anyone knows?
Thanks very much~ :)

Title: Re: How to write a time amplifier?
Post by Marq Kole on Apr 19^th, 2010, 2:01am

What do you mean with a time interval? Is there a delay between the two signals or a phase difference? It is unclear to me what the circuit is supposed to do. Would it be possible to explain or to point to a site where such a function is explained.

Marq

Title: Re: How to write a time amplifier?
Post by 5gougou on Apr 19^th, 2010, 3:51am

The time interval means a time delay between the two signals.
This circuit is going to amplify that delay.
Sorry for the unclear statement.

Please contact if any further confusion. Or you may like to see that circuit in this file:
http://www.staff.ncl.ac.uk/david.kinniment/Research/papers/ElectLett2002.PDF

Thanks very much :)

Title: Re: How to write a time amplifier?
Post by Marq Kole on Apr 19^th, 2010, 7:47am

I would do something like this:

Code:

module time_diff_amp (z, y, a, b);
input a, b;
output z, y;
electrical z, y, a, b;

parameter real thresh = 0.5;
parameter real tgain = 3.0;
parameter real td = 10p;
parameter real tr = 20p;

real out, last_cross_a, last_cross_b, delta_t;
integer sign_t;

analog begin

last_cross_a = last_crossing(V(a) - thresh, +1);
last_cross_b = last_crossing(V(b) - thresh, +1);

@(cross(V(a) - thresh, -1) or
cross(V(b) - thresh, -1)) begin
last_cross_a = 0;
last_cross_b = 0;
out = 0;
end

@(cross(V(a) - thresh, +1))
if (last_cross_a > 0 && last_cross_b > 0) begin
delta_t = tgain * abs(last_cross_a - last_cross_b)
sign_t = (last_cross_a >= last_cross_b);
out = 1;
end

@(cross(V(b) - thresh, +1))
if (last_cross_a > 0 && last_cross_b > 0) begin
delta_t = tgain * abs(last_cross_a - last_cross_b);
sign_t = (last_cross_a >= last_cross_b);
out = 1;
end

V(z) <+ transition(out, td + sign_t *delta_t, tr);
V(y) <+ transition(out, td + (1 - sign_t) *delta_t, tr);

end

endmodule // time_diff_amp

Title: Re: How to write a time amplifier?
Post by 5gougou on Apr 22^nd, 2010, 12:23am

This is the very code I want.
Thank you very much!

Ruili :)