{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

07_Lecutre - L e c tu r e 7 E x t r in s ic C a p a c it a...

Info icon This preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
R. Dutton, B. Murmann 1 Lecture 7 Extrinsic Capacitance R. Dutton, B. Murmann Stanford University
Image of page 1

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

View Full Document Right Arrow Icon
R. Dutton, B. Murmann 2 Extrinsic Capacitance Overlap capacitance Gate to source and gate to drain Junction capacitance Source to bulk and drain to bulk C jdb C jsb C ov C ov
Image of page 2
R. Dutton, B. Murmann 3 Overlap Capacitance Two components Direct overlap ~ C ox WL overlap Additional component due to fringing field Non-negligible in modern technology (gate thickness is large compared to other feature sizes) Simple model equation C ov = C ov ' · W EE114 technology: – C ov '= 0.5fF/ μ m for both NMOS and PMOS Spice model parameters: CGSO=0.5n, CGDO=0.5n
Image of page 3

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

View Full Document Right Arrow Icon
R. Dutton, B. Murmann 4 Junction Capacitance (1) Two components: Area (AS, AD) and Perimeter (PS, PD) capacitance L L diff L diff G S D W AS = W L diff PS = W + 2L diff AD = W L diff PD = W + 2L diff EE114 technology: L diff = 3 μ m
Image of page 4
R. Dutton, B. Murmann 5 Junction Capacitance (2) MJSW DB MJ DB jdb PB V CJSW PD PB V CJ AD C ! " # $ % & + + ! " # $ % & + = 1 1 EE114 Technology CJ CJSW MJ MJSW PB NMOS 0.1 fF/ μ m 2 0.5 fF/ μ m 0.5 0.33 0.95V PMOS 0.3 fF/ μ m 2 0.35 fF/ μ m 0.5 0.33 0.95V MJSW SB MJ SB jsb PB V CJSW PS PB V CJ AS C ! " # $ % & + + ! " # $ % & + = 1 1
Image of page 5

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

View Full Document Right Arrow Icon
R. Dutton, B. Murmann 6 Junction Capacitance in Spice (1) There are two ways to handle junction capacitance in Spice The first one is to compute AS, AD, PS, PD manually for each MOSFET (tedious…) *** netlist *... *... *** model .model my_nmos nmos kp=50u vto=0.5 lambda=0.1 cox=2.3e-3 capop=1 + cgdo=0.5n cgso=0.5n cj=0.1m cjsw=0.5n pb=0.95 mj=0.5 mjsw=0.33 pbsw=0.95
Image of page 6
R. Dutton, B. Murmann 7
Image of page 7

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

View Full Document Right Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern