TECHNICAL WORKSHOP MARATHON 2012
SIMULATION OF AMPLIFIERS USING NGSPICE
VISHNU V
2 nd Year M.Tech VLSI and Embedded Systems
Govt. Model Engineering College, Thrikkakara

ANALYSIS OF AMPLIFIERS USING NGSPICE
CONSIDER THE AMPLIFIER SHOWN IN FIGURE
2

MODEL DESCRIPTION OF TRANSISTOR
MODEL NAME MODEL TYPE
.MODEL GENERIC NPN
Q1 C B E GENERIC

NEED OF COUPLING CAPACITORS
C
OUTPUT NODE
B
E

NEED OF COUPLING CAPACITORS
C
OUTPUT NODE
B
E

NEED OF COUPLING CAPACITORS
WAVEFORM AT BASE NODE AND COLLECTOR NODE
OUTPUT
(COLLECTOR)
INPUT
(BASE)

NEED OF COUPLING CAPACITORS
WAVEFORM AT BASE NODE AND OUTPUT NODE
INPUT
(BASE)
OUTPUT

AFTER ADDING INPUT COUPLING CAPACITOR
C
OUTPUT NODE
B
E

INPUT VOLTAGE

VOLTAGE AT BASE NODE

VOLTAGE AT COLLECTOR NODE

OUTPUT NODE VOLTAGE

EFFECT OF BYPASS CAPACITOR
BYPASS
CAPACITOR

FREQUENCY RESPONSE PLOT WITH BYPASS CAPACITOR

FREQUENCY RESPONSE PLOT WITHOUT BYPASS CAPACITOR

ANALYSE BOTH FREQUENCY
RESPONSE PLOTS AND
MAKE CONCLUSIONS

ANALYSIS OF BJT AMPLIFIERS
ANALYSE THE FOLLOWING CIRCUIT USING NGSPICE

PLOT THE FREQUENCY RESPONSE
PLOTS FOR THE CIRCUIT WITH AND
WITHOUT Rce RESISTANCE

DESIGN A COMMON EMITTER AMPLIFIER FOR
THE GIVEN SPECIFICATIONS AND PLOT ITS
TRANSIENT AND AC RESPONSE USING
NGSPICE ??
(Use Circuit in ELECTRONIC CIRCUITS Lab)

DESIGN COMMON BASE AMPLIFIER AND
COMMON COLLECTOR AMPLIFIER FOR
THE GIVEN CONFIGURATIONS AND PLOT
ITS TRANSIENT AND AC RESPONSE
USING NGSPICE AND COMPARE THE
OUTPUTS
(Use Circuit in ELECTRONIC CIRCUITS
Lab)

MOS AMPLIFIERS
DIFFERENT TYPES OF MOS AMPLIFIERS
COMMON SOURCE AMPLIFIER
COMMON GATE AMPLIFIER
COMMON DRAIN AMPLIFIER

MODEL DESCRIPTION OF MOSFET
MODEL NAME MODEL TYPE
.MODEL MOS1 NMOS
M1 D G S B MOS1 W=22.0U L=0.6U
SCALING PARAMETERS

MODEL DESCRIPTION OF MOSFET CONSIDERING ALL THE
PARAMETERS
.MODEL MOS1 NMOS VTO=0.7 GAMMA=0.5
LAMBDA=0.1 PHI=0.8 CGBO=0.38E-9 CGDO=0.4E-9
CGSO=0.4E-9 CJ=0.57E-3 CJSW=0.12E-9 TOX=9.5E-9
UO=460 LD=0.08E-6 JS=10E-9 MJ=0.5 MJSW=0.4
PB = 0.9

COMMON SOURCE AMPLIFIER
PLOT THE TRANSIENT RESPONSE AND FREQUENCY RESPONSE OF THE
FOLLOWING AMPLIFIER USING NGSPICE

OUTPUT WAVEFORMS – TRANSIENT RESPONSE

FREQUENCY RESPONSE

FREQUENCY RESPONSE WITHOUT BYPASS(CS) CAPACITOR

DC ANALYSIS CONTROL LINE O/P CHARACTERISTICS OF MOSFET
DC VDS 0 5 0.2 VGS 1 4 1
PLOT -vds#branch vs V(2)

TRANSFER CHARACTERISTICS

LAB
SESSION
EXPERIMENTS
LOW PASS AND HIGH PASS FREQUENCY RESPONSE
DC ANALYSIS OF CE, CB and CC CONFIGURATIONS
PLOT TRANSIENT AND FREQUENCY RESPONE OF
CE, CB and CC AMPLIFIERS
CS, CG and CD AMPLIFIERS
EXPERIMENTS IN ELECTRONIC CIRCUITS LAB RECORD

33