Question

(20%) For the RC-tree network shown below, where rw and cw are unit-length wi resistance and capacitance, respectively, and li (i=1, 2, 3) is the length of wire, (a) Use the Elmore delay model to find the propagation delay Tdo from the input to the output vo. (b) Find the Elmore delay tal from the input Vin to another output v. (rw), Cwl, l1) RS (Tw2, Cw2, 1)) W Ro VO Vin I I Co (Tw3, Cw3, 13) WV

Answer 1

Elmore dealy model suggests finding propogation delay by considering resistance from source and equivalent capacitance from input node to output node, and delay equation given by Td = R Ceq

We can draw equivalent Ro model based upon capacitances and resistances per unit length as given, rwe le Mw2 l MA NW Rs Cazla I Cue-he I I Ro Vo Co Vin mina la I (w3lz Ilmone delay model from input I to input ousput vo, vo Tarla I Co Coil I I razlz I crizle • Ve Tdo = رن و ول: از Tdo = r W3 l3 C CH3 l3 + CW, l + CWr la fco) ed, from input Vin to ourput vi (b) Elmore delay CWzdz co Rs CW, & I I LOVE Ť (Wals Tdi = RS LE ci) เS :) Id, RS ( Cwil,+ (W2 l2 + (W3l3+ (o)