Pol Jfet

POLARIZACIONES DEL JFET

YENI PAOLA PÁEZ

ELECTRÓNICA I

2012

POLARIZACIÓN FIJA
Id=Idss(1-VGSVGs Off) 2
Vds=Vdd-ID*Rd= -12-640μA*10K
=5.6V D.C
5.6>Vp--1
5.6>5--1=5.6>4Id=1mA(1--5)2=
VGS | ID |
0 | 1,00E-03 |
-0,5 | 8,10E-04 |
-1 | 6,40E-04 |
-1,5 | 4,90E-04 |
-2 | 3,80E-04 |
-2,5 | 2,50E-04 |
-3 | 1,60E-04 |
-3,5 | 9,00E-05 |
-4 | 4,00E-05 |-4,5 | 1,00E-05 |
-5 | 0,00E+00 |

AUTOPOLARIZACIÓN

ID=1-2*Rs*IDss-1VGSoff ∓1-4*Rs*IDssVGS off2*Rs2 *IDssVGSoff2=
ID=1-21.5K*3mA-14±1-41.5K*3mA421.5K2 *3mA42=
ID+=6.63mA
ID-=1.07mAVds=Vdd-Id*Rd=24v-1.07mA*6.2K=15.7
1.07mA*1.5K=-1.60
15.7>Vp—1.60
15.7>4—1.60=15.7>2.4
Id=Idss(1-VGSVGs Off) 2
Id=3mA(1--4)2=
VGS | ID |
0 | 3,00E-03 |
-0,5 | 2,29E-03 |
-1 | 1,68E-03 |-1,5 | 1,17E-03 |
-2 | 7,50E-04 |
-2,5 | 4,20E-04 |
-3 | 1,80E-04 |
-3,5 | 4,60E-05 |
-4 | 0,00E+00 |

POLARIZACION UNIVERSAL

Vth=Vdd*RG1Rg1+Rg2= 16v*280K2M+280K=1.96vRth=RG1RG2=2M280K=245.6K

Vp=4
IDss=8mA

ID=VGGRs=1.96v1.5K=1.30mA

Id=Idss(1-VGSVGs Off) 2
Id=8mA(1--4)2=

VGS | ID |
0 | 8,00E-03 |
-0,5 | 6,10E-03 |
-1 | 4,50E-03 |
-1,5 | 3,10E-03 |
-2 |2,00E-03 |
-2,5 | 1,10E-03 |
-3 | 5,00E-04 |
-3,5 | 1,20E-04 |
-4 | 0,00E+00 |

AUTOPOLARIZACION CH-P

0=VDD+ID*RS+VGS
-VDD=ID*R2+VGS
--10=ID*2K+VGS
1) Si VGS=0 →102K=ID=5mA
2)VSG=VSG off=10—22K=6mA
Id=Idss(1-VGSVGs Off) 2
Id=10mA(1--2)2=
VGS | ID |
0 | 1,00E-02 |
-0,5 | 5,60E-03 |
-1 | 2,50E-03 |
-1,5 | 6,20E-04 |
-2 | 0,00E+00 |

POLARIZACION UNIVERSALCH-P

VGG=Vdd*RG2RG1*RG2=-15*1M4M*1M=3V
Rth=4M1M=800K
VGS off=-2
IDss=20mA
Id=Idss(1-VGSVGs Off) 2
VSG=2*Rs*IDss-1VSG off±(1-2*Rs*IDssVSG off)2-4*Rs*IDssVSGoff)2*(Rs*IDss-Vgg)2*Rs*IDssVSGoff2
VSG+=-0.65
VSG-=-3.85
VSG=-0.65
VDS>Vp-VGSQ
-16>2-0.65
-16>1.35
Id=Idss(1-VGSVGs Off) 2
Id=20mA(1--2)2=
VGS | ID |
0 | 2,00E-02 |
-0,5 | 1,12E-02 |
-1 | 5,00E-03 |...