-
&LUFXLWHFXGLRGHvQFRQGXF LHSHUPDQHQW
Valoarea curentului care trece prin dioda este determinata de
caderea de tensiune pe dioda
-
&XUHQWXOSULQGLRG LWHQVLXQHDSHGLRG VXQWOHJDWHSULQHFXD
LDGHIXQF LRQDUHDGLRGHL RFGHUHGHWHQVLXQHSHGLRG GHWHUPLQ
YDORDUHDFXUHQWXOXLSULQHD RYDORDUHDFXUHQWXOXLSULQGLRG GHWHUPLQ
FGHUHDGHWHQVLXQHSHHD
,QWURGXFHUH
-
&DUDFWHULVWLFDGLRGHL&DUDFWHULVWLFDFXUHQWWHQVLXQH
SHQWUXRGLRGVHPLFRQGXFWRDUHFX6L
-
)1( = TD
nVv
SD eIi IS - curentul de satura ie
qKTVT = tensiunea termica
25=TV la temp ambianta(aprox 20O C)
n=2 pentru diode discrete n=1 pentru diode din CI
SD Ii >>
T
D
nVv
SD eIi
3RODUL]DUH GLUHFW
-
T
D
nVv
SD eIi IS, VT - depind direct de temperaturala curent constant,
la o cretere a temperaturii cu10C , tensiunea pe diodscade cu
2mV
C2mV/=CT
cstIDD DTTCTTvTv
+= )()()( 1212
'HSHQGHQ DGH WHPSHUDWXU
-
ID=? VD=?
(FXD LH WUDQVFHGHQWDO'RX PHWRGHDSUR[LPDWLYHGHUH]ROYDUH
0HWRGDJUDILF 0HWRGDDQDOLWLF DSUR[LPUL VXFFHVLYH
$QDOL]DFLUFXLWHORUFXGLRGH
-
0HWRGDJUDILF
-
0HWRGDJUDILF
-
6H FRQVLGHU R YDORDUH LQL LDO D WHQVLXQLL SH GLRG GH H[9' 9 L VH
GHWHUPLQ FXUHQWXO SULQ GLRG ,' IRORVLQGHFXD LDGUHSWHL GH VDUFLQ
9' ,' VROX LD LQLWLDOD
&XYDORDUHD ,' VH FDOFXOHD] WHQVLXQHD SHGLRG GLQHFXD LDGLRGHL
DSRLFXUHQWXO ,' GLQ HFXD LDGUHSWHL GH VDUFLQ9' ,' VROX LD
GXSDSULPDLWHUD LH
$VWIHO DP SDUFXUV R LWHUD LH'DF HVWH QHFHVDU R SUHFL]LH PDLEXQ
VHPDLHIHFWXHD] DOWHLQWHUD LL
0HWRGDDQDOLWLF
-
VVD 7,0)0(
=
V635,0nA14mA6,4ln025,02ln
)0()1(
===
S
DTD I
InVV
mA73,45,0635,03)1()1(
=
=
=
RVVI DID
6H FRQVLGHUD9, 95 .LDU 'HVWH1[FX,6 Q$LQ
RVVI DID
=
S
DTD I
InVV ln=
6,45,0
7,03)0(=
=DI mA
0HWRGDDQDOLWLF ([HPSOX
V637,0nA14mA73,4ln025,02ln
)1()2(
===
S
DTD I
IVnV
mA726,45,0637,03)2()2(
=
=
=
RVVI DID
-
3DUDPHWULL VWDWLFL VHGHILQHVFLQUHJLPVWDWLFFF 3DUDPHWULLGLIHUHQ
LDOL VH GHILQHVF LQ UHJLPYDULDELOSDUDPHWULLGHVHPQDOPLF
3DUDPHWULLGLRGHL3DUDPHWULLVHGHILQHVFLQSXQFWXOVWWLFGHIXQFWLRQDUH
-
3DUDPHWULLVWDWLFL
UH]LVWHQ DVWDWLF DGLRGHLD
DD I
Vr =
D
D
DD V
Ir
g == 1
Exemplu:
Q1(0,7V; 16,8mA)
Q2(0,65V; 2,3mA)
== 428,16
7,01Dr
== 2833,2
65,02Dr
gD1=24mS
gD2=3,5mS
FRQGXFWDQ D VWDWLF DGLRGHL
-
$SUR[LPDUHDGHVHPQDOPLFUHJLXQHOLQLDU LQMXUXOOXL4
3DUDPHWULLGLIHUHQ LDOL GHVHPQDOPLFvD(t)=
VD+vd(t)iD(t)=ID+id(t)
8QVHPQDOYDULDELOPLFHVWHVXSUDSXVSHVWHPDULPLOHGHFF
Qd
dd i
vr =
D
Td I
nVr =
Rezistenta diferentiala:
-
Interpretarea rD i rd
0RGHODUHD GLRGHL LQ36)semnal mic (variatii)curent continuu
-
'LRGD =HQHU
Z
Z
Z
Z
Z
Ii
Vv
F
=
Z
zZ
r
rF =
)DFWRUXOUHODWLYGHVWDELOL]DUHDO'=
-
3HQWUXWUHL GLRGHGH:OD DFHODLFXUHQW QRPLQDOIZ = 5 mA avem :1) DZ
3V6 VZ = 3,6V; rzmax = 95; rZ = 0,72 K2) DZ 5V1 VZ = 5,1V; rzmax =
60; rZ = 1,02 K3) DZ 10 VZ = 10V; rzmax = 15; rZ = 2 K
132,072095
1 ==ZF
059,01020
602 ==ZF
0075,0200015
3 ==ZF
([HPSOX
-
Z
dZ V
PI maxmax =
'RPHQLXO GH VWDELOL]DUH DO'=
-
'LRGHOH =HQHU DXXQ FRHILFLHQW GH WHPSHUDWXU &7 FDUH
GHSLQGHDWkW GH WHQVLXQHFkWL GH FXUHQWXO ODFDUH OXFUHD] 'LRGHOH FX
HIHFW=HQHU 9DXXQ FRHILFLHQW GH WHPSHUDWXUQHJDWLY OD
FUHWHUHDWHPSHUDWXULLVFDGH 9= 'LRGHOH FX PXOWLSOLFDUH vQDYDODQ DX
FRHILFLHQW GH WHPSHUDWXUSR]LWLY Q SDUWLFXODU GLRGHOH =HQHU FX 9= 9
DX &7aP9& ODFXUHQWPLF 3H GH DOW SDUWHSHQWUX '=GH9DX&7
aP9&
'HSHQGHQ D GH WHPSHUDWXU
(FKLYDOHQWXOXQHL GLRGH =HQHU GH9FX FRHILFLHQWXO GH
WHPSHUDWXUIRDUWHVF]XW
-
6WDELOL]DWRU SDUDPHWULFGH WHQVLXQH 5HIHULQWD GH WHQVLXQH
/LPLWDWRDUHGXEOH GH WHQVLXQH $MXVWDUHDQLYHOXOXL GH FXUHQWFRQWLQXX
DO XQXLVHPQDOYDULDELO
$SOLFD LL DOH'=
-
8Q VWDELOL]DWRU GH WHQVLXQH HVWH XQFLUFXLWHOHFWURQLFFDUH
SVWUHD]DDSURDSH FRQVWDQWWHQVLXQHD GH LHVLUH OD YDULD
LDLQWUHDQXPLWHOLPLWHD WHQVLXQLL GH LQWUDUH FXUHQWXOXL GH LHVLUH
WHPSHUDWXULLHWF6WDELOL]DWRUXO SDUDPHWULF IRORVHVWH FDSULQFLSLX GH
IXQFWLRQDUHFDUDFWHULVWLFDQHOLQLDUFXUHQWWHQVLXQH D GLRGHL=HQHU
6WDELOL]DWRU SDUDPHWULFGH WHQVLXQH
VO = vI vstabilizator
-
6WDELOL]DWRU SDUDPHWULFGHWHQVLXQH
-
OZI
Z IRVv
i
=
maxmin
Immax
OZ
Zin
IIVV
R+
=
minmax
Immin
OZ
Zax
IIVV
R+
=
minmax
L
ZO R
VI =
max
minL
ZO R
VI =
R ( Rmin ; Rmax )
6WDELOL]DWRU SDUDPHWULFGHWHQVLXQH
-
I
I
O
o
V
Vv
Vv
F
=
RRrRr
v
v
Lz
Lz
I
O
+
////
LZ
LZ
O
I
R//rRR//r
VV +
=
RrRr
r
rF
z
Z
Z
zV +
+=
ZLZLZ
zLzLz
rRrRrrRrRr
-
Io
-
/LPLWDWRDUHGXEOH GH WHQVLXQH
-
$MXVWDUHDFRPSRQHQWHL FRQWLQXHD XQXLVHPQDOYDULDELO
