Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Introduction

This project is composed of 2 parts

• Cascode amplifier

• Single – stage differential amplifier

Deadline : Submit hardcopy

until 18:00 PM on April. 26, 2018 @ C531

Late penalty : -10 point per day

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

AC Simulation

1kHz to

1MHz

Sweep

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Marker Setup

If you want to place VDB marker, just simulate it first (AC sweep).

and then, you can see dB marker is activated (If you don’t simulate it before, it might be deactivated.)

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 1 : Cascode Amplifier

Parameter Value

Av > 30 dB

Output

Impedance> 30 kΩ

Power < 1.25 mW

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 1: Cascode Amplifier

• Gain Simulation Setup

Use VDB marker

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 1: Cascode Amplifier

• Gain Plot

gain > 30 dB

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 1: Cascode Amplifier

Part Name : IAC

Use V marker (Not VDB marker)

• Output Impedance Simulation Setup

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 1: Cascode Amplifier

• Output Impedance Plot

( )( )

( )

V jZ j

I j

( ) 1I j

( ) ( )Z j V j

Output Impedance > 30kΩ

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 2 : Single-Stage Differential Amplifier

Parameter Value

Av > 40 dB

CMRR > 70 dB

ICMR > 1.4 V

Power < 1.25 mW

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 2 : Single-Stage Differential Amplifier

Part name : E

(works as VCVS)

Input Common

Mode Voltage

Set ACMAG to 1

Set E’s gain to 0.5 & -0.5 each

• Differential Input Pair

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 2 : Single-Stage Differential Amplifier

• Differential Input Pair

V 0.5CM

V V

0.5CM

V V

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 2 : Single-Stage Differential Amplifier

• Differential Mode Gain (Adm)

Differential mode gain > 40 dB

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 2 : Single-Stage Differential Amplifier

• Common Input Pair

Set All E’s gain to 1

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 2 : Single-Stage Differential Amplifier

• Common Mode Gain (Acm)

Common mode gain

CMRR = |Adm/Acm|

But out gains are dB scale,

CMRR (dB) = Adm (dB) – Acm (dB)

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Design 2 : Single-Stage Differential Amplifier

Step 1 : Parametric sweep of Vcm from 0 V to 2.5 V (Main sweep is AC sweep)

Step 2 : Check the Vcm which shows a gain lower than the gain when Vcm is 1.25 V.

Step 3 : Find the maximum & minimum voltage that satisfies above condition.

Step 4 : Vmax – Vmin = ICMR

• Input Common Mode Range

Electronic Circuits 2 (18/1) W.-Y. Choi

Lect. 12: Project 1 Design Guide

Grading Policy

• Cascode Amplifier [25], Single-Stage Differential Amplifier [25], Design Report [50]

• 5 extra point will be given for up to three designs for each part that satisfy all the specification and

produce the highest gain per power (Gain/Power)

• Best designs will be selected from Part I and II each and their designers will be given opportunities

to present their results for 5 extra point (optional)

• All plots I showed you in this lecture must be in your design report. And your design report must have

the method of design each circuit to satisfy specification and the comparison between the simulation

result and analytical solution you learned in class. Report must be written in English.

• Late penalty is -10 point per day.