assignment5

assignment5 - Ccbx Rbb ECE145C/218C PS5 Above is a device...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1 cbi C bb R be C ' ' e b m V g be R ex R + - ' ' e b V cbx C ECE145C/218C PS5 Above is a device model . Recall that f m depl be be g C C τ + = , . Let us take Cje=32 fF, beta=50, Ccbi=2.2 fF, Ccbx=6.0 fF, Rbb=38 Ohms, Rex=2.8Ohms, and tau_f=0.28 ps. Lets use this device model in circuit calculations below. The transistor, incidentally, has Ae=0.6 um x 4.3 um emitter area, has a peak 450 GHz ft and 490 GHz fmax, operates at a maximum of 12 mA/um^2 at Vce=0.7 volts. Unlike previous problem sets, do not move all the collector-base capacitance inside Rbb. This is the hand analysis model; please use the HBT_gen5 scalable HBT model in ADS for circuit simulations. More details --though not needed for this problem set-- regarding this transistor can be found at http://www.ece.ucsb.edu/Faculty/rodwell/Downloads/Publications/Griffith_DRC2005_digest.pdf R L L R ef R ee -V ee R ef B A C B A C Problem 1: Please find the A-level propagation delay of a CML XOR gate. The circuit diagram is the lower figure: the pull up resistors are 50 Ohm, while the
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 08/06/2008 for the course ECE 145 taught by Professor Rodwell during the Fall '07 term at UCSB.

Page1 / 2

assignment5 - Ccbx Rbb ECE145C/218C PS5 Above is a device...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online