ECE584 HW #1 Spring 2018

PROBLEM #1

Design a 1.6K RPOLYH resistor.

Rp2h 1200Ω:= R1 1.6kΩ:=

SR1

Rp2h

R10.75=:=

Select a width of 4 um.

W1 4μm:= L1

W1

SR15.333 μm=:=

Design a 300 Ohm poly 2 resistor.

Rp2 50Ω:= R2 300Ω:= SR2

Rp2

R20.167=:=

W2 4μm:= L2

W2

SR224 μm=:=

Design a 800 Ohm ZTC resistor.

R3 800Ω:=

Put two resistors in series. The A resistor will by POLY2 and the B resistor will be POLYH.

RA 0.56 R3 448Ω=:= RB 0.44 R3 352Ω=:= RA RB+ 800Ω=

SRA

Rp2

RA0.112=:=

WA 4μm:= LA

WA

SRA35.84 μm=:=

SRB

Rp2h

RB3.409=:=

WB 15μm:= LB

WB

SRB4.4 μm=:=

PROBLEM #2

Design a 0.2 pF double poly capacitor. fF 1015-

F:=

Cpp 0.86fF

μm2

:= Square caps match best! WC LC=

Cu 200fF:= WC

Cu

Cpp15.2 μm=:=

Design a 1.2 pF unit capacitor.

Cu 1200fF:= WC

Cu

Cpp37.354 μm=:=

PROBLEM #3

Design a 100K NMOS resistor.

RNFET 100KΩ:=

VDD 3.3V:= VS 1.65V:=

KPN 170μA

V2

:= VGS VDD VS-:=

From the handout graph VTN 0.8V:=

VEFF VGS VTN- 0.85V=:=

SN1

RNFET KPN VEFF0.069=:=

Choose WN 1μm:= LN

WN

SN14.45 μm=:=

VEFF

50.17V= so keep drain-sourve voltage less than 170 mV

Repeat for a PFET

RPFET 100kΩ:=

VDD 3.3V:= VS 1.65V:= VG 0V:=

VSG VS VG- 1.65V=:= VTP 0.95- V:= BODY EFFECT

KPP 60μA

V2

:= VEFF VSG VTP- 0.7 V=:=

SP1

RPFET KPP VEFF0.238=:=

Choose WP 2μm:= then LP

WP

SP8.4μm=:=

VEFF

50.14V=

Keep source-drain voltage less than 114 mV.

PROBLEM #4

θIDS

2 n S KPN UT2

=

UT 25.9mV:= n 1.3:= KPN 170μA

V2

:= IDS 10μA:= LN 2μm:=

Width as a function of the inversion coefficient.

WN θ( )LN IDS

2 n θ KPN UT2

:=

WN 0.1( ) 674.541 μm=

WN 3( ) 22.485 μm=

WN 30( ) 2.248 μm=

PROBLEM #5

Determine the transconductance for the transistors from PROBLEM 4.

gm θ( )1 e

θ--

θ

IDS

n UT:=

gm 0.1( ) 2.546 104-

1

Ω=

gm 3( ) 1.411 104-

1

Ω=

gm 30( ) 5.4 105-

1

Ω=

PROBLEM #6

Determine the output resistance for the transistors from PROBLEM 4

From the handout, find the early voltage per unit length.

LN 2μm:= IDS 10μA:=

VEN 21.1V

μm:= VE VEN LN 42.2V=:=

ron

VE

IDS4.22 MΩ=:=

Determine the effective voltage when theta is 30.

gm VEFF 2 IDS=

VEFF 2IDS

gm 30( ) 0.37V=:=

Determine the effective voltage when theta is 3.

VEFF 2IDS

gm 3( ) 0.142V=:=