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.
1.
(MOSFET - Metal Oxide Semiconductor Field Effect Transistor). , 1930 , 20 . 50- , , , 70- . - . . , , , .
2.
. , , . , , . , , . , , / . n+ 20-200 , . + p , n - . -, n + - (a) , . , . , , , + n n+ , , p p . - n - - n + . , (b) V- . - - , , n+ n+ p n . RDS(on), p . p-n (b) 2,2mV/°C, . 1 1
0.7%/°C 1%/°C, , , . - , , - , , , , . , . - 30% - . , , . 1. 1970- , . . V- (Trench ). , - , , . , . - . , , DC-DC . , , . , , , . Spice / Saber , , . , , .
DRAIN DRAIN GATE GATE GATE DRAIN
SOURSE
SOURSE SOURSE
(a)
(b)
(c)
. 2 , , . , , . . 2 , , . . 2a , . , . 2
. 2b , . - ( ) - . , . - . . 2c . , . , . . ( 10 60 ) ( 20 200 ), . . 2, , , , , , , . , . , CGS CGD , , CDS . CGS , , . CGS - . , :
C GD
C GD,0 1 + K1 · VDS
CDS , , :
C DS
C DS,0 1 + K 2 · VDS
, , CISS , CRSS COSS : CGD = CRSS CGS = CISS - CRSS CDS = COSS - CRSS , CGD . , - . , :
C GDeqv = (1 + g fs · R L ) · C GD
CGD CDS , , , . ,
3
. : CGD, ave = 2 · C RSS,spec · VDS,spec VDS,off VDS,spec VDS, off
C OSS, ave = 2 · COSS,spec ·
- , RG,I. , , , , . , , , . , RG,I - . , 4, . , , VTH, . , +25° , 250. , . - - VTH, -7/°. (Logic Level MOSFET), VTH . , VTH . F. , , , , , . , gfs, :
g fs =
dI D dVGS
, :
I D = ( VGS - VTH ) · gfs
VGS, :
I VGS, Miller = VTH + D gfs
, (LS) (LD), . , LS LD , . ( ), , , .. , , , , , .
4
3.
, , . , ; . , , . . 3, - . , , ( ).
IDC
RGATE
+ V OUT -
V DRV
. 3
ID V DRV D . 4, CGD CDS RGATE RHI RG,I . G CGS IG 0 VTH. S CGS, CGD ( CGD ). , , . VGS , . VTH VTH , VGS,Miller. - . IG , , CGS CGD , , VDS,off. , . 3. VDS , , . , ID VGS,Miller , , . , , 1 2 3 4 . . , , . 4 CGD -. , IDC. - . VGS,Miller VRDV,
5
CGS CGD. , - , . ID V DRV D , . 5, CGD , , CDS RLO RGATE RG,I . G , CGS IG IDC, S RDC(on). , , CISS . CGS CGD. V GS , (- V TH ). , , - IG ID·RDS(on) , , . CGD, , V DS . , VDRV, . , IDC . 3. ID . VGS,Miller VTH, CGS, CGD 1 2 3 4 . , , . 5 . , "" . , , . ( CGS) . , , , , . . , . , , . , , .
6
. , - . , CISS, , VDRV, -. . 6. - (- , ), . , :
VGS , - (V)
V DRV
V DS QG Q G , (nC)
. 6 VDRV - , fDRV - , . , QG fDRV . . 4 5, , - , . , . 4 5, :
PGATE = VDRV · Q G · f DRV ,
PDRV, ON =
1 R HI · VDRV · QG · f DRV · 2 R HI + R GATE + R G, I 1 R LO · VDRV · Q G · f DRV · 2 R LO + R GATE + R G, I
PDRV, OFF =
PDRV = PDRV,ON + PDRV,OFF , , . , , . , ; , . , , ( ), . , , 2 3 , , VTH VGS,Miller. : ( , ) . ( VDRV) , , . 5, Logic Level - 2,5, , , .
7
, , 2 3. :
I G2 =
VDRV - 0.5 · ( VGS, Miller + VTH ) R HI + R GATE + R G.I
I G3 =
VDRV - VGS, Miller R HI + R GATE + R G.I
, IG2 VTH VGS,Miller, IG3 CRSS VDS(off) , 2 3:
t 2 = C ISS ·
VGS, Miller - VTH IG2
t 3 = C RSS ·
VDS, off I G3
t2 VDS(off), IL, t3 VDS(off) . , ( ):
P2 =
t2 I · VDS, off · L T 2 VDS, off t3 · IL · T 2
P3 =
:
PSW =
VDS( off ) · I L 2
·
t2 + t3 T
, , . , , . , - , , . - , . . . . , , . .
RG
LS CISS
V DRV
. 7
8
, . 4 5, . , , , .. / . , CISS , . 7. , , . , , LS CISS, ( ) , - . RGATE, : R GATE,OPT = 2 · LS - ( R DRV + R G , I ) C ISS
, . , , . . 2 3 . VTH VGS,Miller, , VDRV-VGS. , . , , , . , - . - - . ( , ). , , . LD·di/dt. , . LD, , . , , VDS(off), .
4.
V DRV (VBIAS ) , VCC - , . 8. CDRV , . 8 RGATE OUT . - GND , , ! . , . 8 , - , . - - 1,
-
9
"" . , , , , . ( ), . , . , , 0,1 1. 1. .
. , , , . , . , . , , , , , :
VQ =
I Q, HI · D MAX C DRV · f DRV
- . , , . . , :
VQG = QG C DRV
, CDRV, :
I Q, HI · D MAX + QG f DRV , V
C DRV =
IQ,HI - , DMAX - , fDRV - QG - . 2. , , , . . . 9, n-p-n , . n-p-n . , . . , -
VDRV VCC -
OUT
R GATE
GND
!
. 9
10
, . - , . , , , . VBIAS V DRV R VCC , . 10. , RB R GATE , OUT . , ( ) , GND ! . , . . 10 n-p-n p-n-p . . . RGATE . 10 , RB . . , , , RGATE , VBIAS+VBE GND-VBE . . , , VBIAS V DRV . 11. , R , VCC . , R GATE OUT , . . 11 , GND ! , . , . 11 , , . , . , . , , . , (. . 3), 11
- -
. , , . , , VDRV, ( ) . , . . , . , , . / . , - , , . 1. , - , . 12. , - . (, ) , RGATE. DOFF , . , :
IG > VD, FWD R GATE
VCC
V DRV
R OUT
GATE
D OFF GND
. 12
, (, 1N4148), 150mA, , BAS40 - 300mA. , - . , . - - , . 2. p-n-p , V DRV p-n-p , . 13. QOFF VCC , ; RGATE, DON , , DON R QOFF. GATE OUT Q , DON QOFF OFF . GND - , - . . 13 p-n-p ; , , . QOFF
12
- , , , . , /. (. . 10), n-p-n . GND-0.7V VDRV+0.7V , . - - . 3. n-p-n , . 14, V DRV R GATE DON . n-p-n VCC , . , , OUT Q OFF , . Q INV , - GND , (, QINV ). , . 14 n-p-n , . , QINV , . V DRV , n- VCC , . 15, R GATE OUT . Q OFF OUT . RGATE , GND . , , . 15 COSS CISS . . , , , "" , . 4. dv/dt , . , . :
13
R GS <
VTH dt · CGD dv TURN - ON
dt/dv - . , . , . , . "" - . , , - , . dv/dt . , , -. , .. , :
V - 0.007 · ( TJ - 25) dv = TH dt LIMIT R G, I · C GD
VTH - 25°, -0,007 - , RG,I - CGD - - . , , , . , , :
R MAX =
VTH - 0.007 · (TJ - 25) dv , · C GD dt MAX
RMAX=RLO+RGATE+RG,I. , . , . 25°, . , , , RGATE . , p-n-p (. . 13) . p-n-p , dv/dt:
VTH - 0.007 · (TJ - 25) dv = dt + R LO R R G, I + GATE · C GD
dv/dt , . , , .
14
5.
, , Q FW , Q SR . n- , IL V , . - , CDS CGD . . 16 , - . , . . 16 - QSR. , , - QFW. , . - . , . , , . , . - 20 80 - , . , . , , , . , CGD CDS ; - . , CGD CDS VDRV. :
CGD,SR = 2 · C RSS.SPEC · VDS,SPEC 0.5 · VDRV
, :
Q Q,SR = (C GS + C GD,SR ) · VDRV
, . , , , . , . , - . . , , . , CGD , . . 17 . , .
15
. 17 . , . Q FW QSR Q SR QFW. V IL QFW , QFW R LO,SR . CRSS . QFW . , , QSR Q FW . Q SR V IL . R LO,SR . , QFW. QFW , QSR . 17 . CRSS . , . , , (, , ). , dv/dt . : VDRV - VGS, PLATEAU ( FW ) dv = dt TURN - ON ( FW ) ( R HI( FW ) + R GATE( FW) + R G , I ( FW ) ) · C RSS( FW )
VTH (SR ) dv = dt MAX (SR ) ( R LO(SR ) + R GATE(SR ) + R G , I(SR ) ) · C RSS(SR )
dv dv < dt TURN - ON ( FW ) dt MAX (SR ) , , , , :
R LO(SR ) R HI ( FW ) VTH (SR ) VDRV - VGS, PLATEAU ( FW )
, , 10V, 0,417, . , , VDRV, , . 16
6.
, (n- p-), - , (bootstrap). , , , : · · · · · dv/dt · · · · p- p- . , . , p- , . , . 1. p- p- - , . 18 - , - . - DC-DC 12. , - , , , p- . n . , . , , , . p- , , . , , . 19. , . . . ROFF RGATE , 2.
V DRV =V IN VCC
-
R OUT
GATE
GND
. 18 p-
VCC
VDRV
V IN
R R OUT
GATE
OFF
GND
. 19 17
. , (, , ). dv/dt . , , . . 20 , V BIAS V IN , VCC R1 . QINV, , - R GATE R2 . OUT RB R2 RGATE, , Q INV , . , GND , . , , . 20 . , , (- ) (- ):
V · D MAX PDRIVE = Q G · VDRV · f DRV + IN R1 + R 2
-
, VDRV - R1R2, . QINV, . , , R2 QINV. , . R1 - , , . , , , . , QINV , R1 . - dv/dt . , , . , , . n- n- - , . , . n- . 1. n- "" ( ), . : VDRV < VGS,MAX VIN < VDRV - VGS,Miller 18
p-nV DRV V IN p . 21. VCC , . R GATE OUT , , . GND -. , . 21 n- , . , - p-n . . CGD . - , , . , , . n2 1 - . . 22 L S . V IN 3 - . L D , , . , , . , - , - . V DRV CGD . 1 0,7, . , V IN+V GS,Miller , 1 , , . V IN 1 - , . V GS= 1 + 1 , . 21. : , . 22 n- ,
-
19
. , , . , . 21. p-n-p , VBE, . , , , 0,7. , VTH, . - , . , n- . , . , . , , . 2. V DRV D V IN BST . 23. C BST - , VCC , R GATE . Q LS VOUT QBST, R1, R2 QLS. OUT , CBST, GND RGATE. . 23 12 24 , , . , . , n , . . . , QLS , R1 , . CBST. , , DBST QLS . , QLS. R1 R2, . , , . CBST , , DBST, CBST VDRV.
-
20
3. V DRV V IN , 24- 48- - , - , VCC . 24. D BST , 600, VBST R GATE OUT ( ), , C BST SRC , . GND , - . 24 0,5 . V BST " " (pulsed latch), . 25. R Q , - OUTH S Q , , . , SRC , , . 25 Pulsed Latch . , . - . 600- 120; . - + . ( 100) , .
4. n- . 26. n- , . . , , , , CISS RGATE. - , "" ( SRC VS), .
21
V DRV
D
BST
V IN
VCC
-
VCC C DRV IN
VB C BST R OUT
GATE
OUT
GND GND
VS
. 26 , . "" CBST , "" - VDRV, VDRV, . , , , , , , . , . 27. SRC , SRC . RGATE V DRV V IN - - -, , , -, VCC D BST . VBST OUT . C R BST GATE SRC , GND . - CBST RGATE, CBST , . 27 SRC .
22
5.
-
V BIAS V DRV D V IN
BST
VCC
-
C IN C BST R
GATE
C BIAS
C DRV
VCC
VB
OUT
IN
OUT
V OUT
GND GND
VS
C OUT
. 28 . 28 . - CBST, . : (QG), (QRR) (ILK,D) DBST, (IQ,LS), (IQ,DRV) (IGS) ( , ). , - . UBST . Q G + Q RR + I BST · U BST D MAX f DRV ,
C BST =
IBST=ILK,D+IQ,LS+IQ,DRV+IGS
CBST . , CBST . , . (t ON,MAX) . CBST : C BST, MIN = Q G + Q RR + I BST · t ON , MAX , VBST - VUVLO
VBST - , VUVLO - . , , . , , . CBST , . : C BST, MIN = Q G + ( I LK , D + I Q, LS + I Q, DRV ) · t OFF, MAX VBST - VUVLO
23
V BIAS
V DRV
D
BST
V IN
D START VCC
-
R START C IN
C BIAS
C DRV
VCC
VB
C BST
DZ R
GATE
V OUT
OUT
IN
OUT
GND GND
VS
C OUT
. 29 , , . CBST , , . . RSTART, DSTART DZ, . 29. DZ , RSTART - . 6. n- . (. 28) . . , , . - , "" , RGATE, . . CGS "" , RGATE , . CGD : RGATE, "" , , , CIN.
V BIAS V IN
VCC
-
VCC
VB
R OUT
OUT
IN
GATE
GND GND
VS
V BIAS
V IN
VCC
VCC
VB
R HO
-
OUT2
HI
GATE
VS
OUT1
LI
LO
GND GND
COM
. 30 24
. - . , , VS ( ). CBST DBST CDRV, . "" "" . , , CDRV , CBST. . "" , , . . 30 . , , , . - . / , ( GND) (COM). - COM "" . - . , (CBIAS . 28), . , , - CDRV CBST.
7. ,
V DRV - VCC . 31 , +V DRV V DRV -V CL -VCL VDRV-VCL, 0V -V CL VDRV. OUT VCL C C , I C,AVE =0 -V R CC. CL SG - GND . , . 31 - . - CC RGS. RGS - , . , - CC . RGS. . ( CC ), RGS , . , CC , :
V - VC D QC,ON = QG + DRV · R GS f DRV
-
25
, CC :
Q C, OFF = Q G +
VC 1 - D · R GS f DRV
DC (VCL / VDRV ) C
, , VC:
VC = VDRV · D
1
0.8
, . . 32 , , . , , RGS. . 32. , . .
0.6 V CL V DRV
0.4
0.2
0
0.2 0.4 0.6 0.8
1
. 32
, , , VC . , . CC :
VC =
QG ( VDRV - VC ) · D + CC C C · R GS · f DRV
, VC = D · VDRV CC, :
CC =
QG V · (1 - D ) · D + DRV VC VC · R GS · f DRV
, D=0.5. , 10% VDRV . C CC , RGS. . . , VC , VC CC RDS. , , . :
CC =
QG V · (1 - D ) · D + DRV VC VC · R GS · f DRV
CC
26
= R GS · C C R GS =
RGS , D=0.5 VC=0.1·VDRV, :
C C, MIN =
20 · Q G · · f DRV VDRV · ( 2 · · f DRV - 5)
CC,MIN, RGS. , RGS , - .
8.
"" , , . , , . , , . . , , (, , ). , . · , , . , - . , . · . "flyback" . , - . . . , , . · , . , , - . · , , . . · (, ) , B - H . . , . (. 33) - . CC, , - , . CC , , :
VC = D · VDRV
27
-
, LC , CC. RC, . :
LM RC 2 · CC
V DRV VCC +V DRV V DRV -V C
0V VC OUT R
C
-V C -
+ C
C
R
GS
GND
, RC - . , RC , . , LC , . , VC - , RGS ( ). , :
. 33
VOUT VT IM
=
2 · · f DRV · L M · R GS · CC 2 · · f DRV · L M + R GS
IR
IG . . 34 IOUT . . , I OUT . - , (, . 34 ) . , . . , , . 33 , . , , - . .
28
-
. 35 , . CC2 DC2. , . 31. 1.
V DRV VCC +V DRV V DRV -V C V DRV -V D
0V VC OUT RC + C C1
-V C VC -VD
-V D
C C2 D R
C2 GS GND . 35 . CC2 - : , RGS .
C C2 =
- VDC2, FW ) · D MAX (V QG + DRV VC2 VC2 · R GS · f DRV
CC2 , .. . , CC1 :
C C1 =
( VDRV - VDC2, FW ) · D QG VDRV · ( D 2 - D 3 ) + + 2 VC1 VC1 · R GS · f DRV 4 · VC1 · L M · f DRV
, . , , . , 0,6 0,8. , VC1+VC2. , , . 2. - "" . , , . , . , , - . , . , , , . - . , , , , . , . , RM, P , . - , . , ; , .
29
, , :
V TR * t V DRV * T DRV
V ·t , N P = TR B · A e
1
0.8
VTR - , B - 0.6 t, Ae - . 0.4 . . 36 0.2 - . 0,5. 0 0.2 0.4 0.6 0.8 1 , - , . 36 . , , . , , . , , . . . , , , . . - (P, RM ), , "" ( ) , , "" . . , "" - .
3.
, , . 37 38 . . 37 , . . . , . , - . CC2 DC2 , . DC2 . . , . , . , , .
30
V DRV VCC +V DRV
-
V DRV -V C
V DRV -2 * V D
0V VC OUT RC + CC1
-V C VC -VD
C C2
GND
. 37 - 1
V DRV VCC V DRV -2 * V D
PWM AM
OSC
GND
. 38 - 2 (. 38) , , . . 38 , . , - , . - , . (. 39). . , , . . . . .
V DRV VCC R GATE V IN
-
OUTA
R GATE OUTB
GND
. 39 31
, , . (DA DB) :
I DC =
VDRV · (DA - DB ) 2 · R EQV
DA=0.33 DB=0.31 ( 6%!), VDRV=12V REQV=5 . 24mA 3mW. . VDRV , . , .
9.
. : · · , , . - , , - . , . , , , , , , .. - , , . . , . , , , . ( ) . , . . , , . , - , . .
·
· · · · · · · · · · · · · ·
32
, , . , , . , , A - E, . F . , , , .
33
A
. ( CGS, CGD, CDS, , , , , ) IRFP450. .
V DRV
VDS,off ID D CGD IRFP450
RHI R GATE G RG,I CDS
RLO CGS S
: VDS,OFF = 380V ID = 5A TJ = 100°C VDRV = 13V RGATE = 5 RLO = LHI = 5 -
A1
IRFP450 : CISS COSS CRSS Input Capacitance Output Capacitance Reverse Transfer Capacitance 2600 720 340 pF VGS = 0V VDS = 25V f = 1.0MHz
:
C RSS,AVE = 2 · C RSS,SPEC ·
VDS,SPEC VDS,off VDS,SPEC VDS,off
C RSS,AVE = 2 · 340pF ·
25V = 174pF 380V 25V = 369pF 380V
COSS,AVE = 2 · COSS,SPEC ·
C RSS,AVE = 2 · 720pF ·
1
: CGD = CRSS,AVE CGS = CISS - CRSS CDS = COSS,AVE - CRSS,AVE CGD = 174pF CGS = 2600pF - 340pF = 2260pF CDS = 369pF - 174pF = 195pF
, CGS . , . , CGS , , CGD CDS . , .
A2
, - . IRFP450: QG QGS QGD Total Gate Charge Gate-to-Source Charge Gate-to-Drain ("Miller") Charge 150 20 80 nC
ID = 14A VDS = 400V VGS = 10V
20 - VDS = 400V I D = 14A , VDS = 400V 16 VDS = 400V ( ). 13V - (13V) 12 ( , - 8 ), . 4 , 0 . - 0 20 40 60 80 100 120 140 Q G, Total Gate Charge (nC) 122nC , . , A1 CRSS,AVE. , , - -.
3.
, , . - VTH gfs. IRFP450 : VGS(th) gfs Gate Threshold Voltage Forward Transconductance 2.0 9.3 4.0 V S VDS=VGS, ID=250µA VDS = 50V, ID=8.4A
, , . .
VGS , Gate-to-Sourse Voltage (volts)
2
-. , , -. . , - - , - . , VGS1 VGS2 . 150° :
I D2
I D , Drain Current (amps)
10
1
150 C
0
0
25 C I D1
0
10
VDS = 50V 20us PULSE WIDTH 4 V GS1 5 V GS2 6 7 8 9 10
ID1 = 3A VGS1 = 4.13V ID2 = 20A VGS2 = 5.76V
V GS Gate-to-Sourse Voltage (volts)
:
I D1 = K · ( VGS1 - VTH ) 2
I D 2 = K · ( VGS2 - VTH ) 2
VTH =
VGS1 · I D2 - VGS2 · I D1 I D 2 - I D1
VTH =
4.13V · 20A - 5.76V · 3A = 3.175V 20A - 3A
K=
I D1 ( VGS1 - VTH ) 2
K=
3A (4.13V - 3.175V) 2
= 3.169
VGS, Miller = VTH +
I LOAD K
VGS, Miller = 3.157V +
5A = 4.413V 3.169
150° - . 100° : VADJ = (TJ - 150°C) · TC V VADJ = (100°C - 150°C) · - 0.007 = +0.35V °C
A4.
, - RG,I. . , , . , . RG,I . -, ESR . , , Rs-Cs (, , Rs-Cs-Ls). RG,I, CISS . IRFP450 HP4194 RG,I=1.6. 12.9nH, - 5.85nF.
3
A5.
-. - , , -. , . . , CGD CGS. , -:
IRFP450
VGS = VDS ·
CGD C GS + CGD
RG,I G
D CGD
VGSVTH dv = dt N - LIMIT R G, I · CGD
CDS
dv/dt
CGS S
IRFP450
D CGD
RG,I G
CDS
dv/dt
CGS S
, - , , . , , . - :
VTH = dt LIMIT ( R G, I + R GATE + R LO ) · C GD dv
RGATE G
IRFP450
D CGD
RG,I
CDS
dv/dt
. -. 100° .
RLO CGS S
4
1: , dv/dt: C + CGD VDS, MAX = ( VTH + VADJ ) · GS CGD 2: dv/dt :
V + VADJ dv = TH dt N - LIMIT R G, I · C GD dv 3.175V + 0.35V kV = 6.4 = dt N - LIMIT 1.6 · 340pF µs
VDS, MAX = (3.157 V + 0.35V) ·
2600pF = 26.82V 340pF
3: dv/dt :
VTH + VADJ dv = dt LIMIT ( R G, I + R GATE + R LO ) · C GD dv 3.175 + 0.35 V = = 889 dt LIMIT (1.6 + 5 + 5) · 340pF µs
5
B
. , , . . : · V IN , . V DRV V BIAS - VCC R GATE OUT . ! , GND - ! , . · - , - . . , CGD. IRFP450 MIC4423. 2.5mA, . 100, 0.7. 12, 300. 115nC. 5% 12 0.6. :
-
C BYPASS =
I Q, HI ·
D MAX + QG f DRV V 0.7 + 115nC 100kHz = 221nF 0.6V
(nF)
500
C BYPASS =
2.5mA ·
400
. , . . , , D=0.7.
300
200
10
100 (kHz)
1000
1
IRF1310N IR2125 48. .
V BIAS
V DRV
D
BST
V IN
VCC
-
C IN C BST RGATE QM V OUT RGS
C BIAS
C DRV
VCC
VB
OUT
IN
OUT
GND GND
VS
C OUT
: VIN,MAX = 65V VDRV = 12V VBST = 0.5V VBST,MAX = 3V fDRV = 100kHz DMAX = 0.9 CBST CBST - -
TOFF,TR = 400µs TON,TR = 200µs
: QG = 85nC RGS = 5.1K IR = 10µA VF = 0.6V ILK = 0.13mA IQBS = 1mA IRF1310 VDRV = 12V VDS = 65V RGS DBST TJ = 80°C DBST 0.1A TJ = 80°C TJ = 100°C ,
2
:
V - VF D MAX I R + I LK + I QBS + DRV · + QG f R GS DRV C BST ,1 = VBST
, :
12 V - 0.6V 0.9 + 85nC 10µA + 0.13mA + 1mA + · 5.1K 100kHz C BST,1 = = 231nF 0.5V
( ) . , , . , . , . , , :
V - VF I R + I LK + I QBS + DRV · t OFF, TR + Q G R GS C BST,2 = VBST, MAX
:
12 V - 0.6V 10µA + 0.13mA + 1mA + · 400µs + 85nC 5.1K C BST,1 = = 478nF 3V
, 200µs . , :
V - VF I R + I LK + I QBS + DRV · t ON, TR R GS C BST,3 = VBST , MAX
:
12 V - 0.6V 10µA + 0.13mA + 1mA + · 200µs 5.1K C BST,3 = = 225nF 3V
, 470nF. , CDRV . . CDRV>>CBST, VDRV, . : . :
C DRV 10 · C BST,1 = 2.2µF
3
D
- . 3 .
V DRV VCC +V DRV
-
V IN
V DRV -V CL
CDRV 0V OUT + C VC -V CL
C
-V
CL
R
SG
GND
: dVIN/dt = 200V/ms CGD,0 = 1nF VTH = 2.7V VDRV = 15V fDRV = 100kHz DMAX = 0.8 VCL = 3V VC = 1.5V QG = 80nC = 100µs , - , -, , VC
- RGS, . - CGD , , dVIN/dt, RGS. , RGS . , :
R GS =
VTH dV CGD,0 · IN dt
R GS =
2.7V 1nF · 200000 V s
= 13.5k
4
. : = ·RGS
CC =
Q G · · f DRV VC · · f DRV - VDRV · D + VC ( D) · D
VC(D) . . , VC(D) = D·VDRV, , D=0.5, . 3V . D>0.2 , VC=3V. , , D=0.5. , CC, . , . :
MIN =
D · ( VDRV - VC ( D )) VC · f DRV
D=0.5 , D=DMAX . . , :
MIN =
D MAX · ( VDRV - VCL ) VC · f DRV
MIN =
0.8 · (15V - 3V ) = 64µs 1.5V · 100kHz
CC =
Q G · · f DRV VC · · f DRV - D MAX ( VDRV - VCL ) CC
CC =
80nC · 100µs · 100kHz = 148nF 1.5V · 100µs · 100kHz - 0.8(15V - 3V ) 100µs = 675 148nF
R GS =
R GS =
, MIN< RGD,MAX>RGS. , D=0.8, RGS 173mW. , , . , . 1V (VDRV=1V), CDRV :
C DRV =
QG VDRV - VCL + · D MAX VDRV VDRV · R GS · f DRV
C DRV =
80nC 15V - 3V + · 0.8 = 222nF 1V 1V · 675 · 100kHz
5
.
V DRV VCC T DRV OUTA
-
VIN
T DRV
OUTB
OUTC
OUTD
GND
- . : fCLOCK = 400kHz fDRV = 200kHz DMAX = 0.5 VDRV = 15V ,
. . . RM5/I, , Ferroxcube, 3C94 200kHz. : Ae = 24.8mm2 Ve = 574mm3 BSAT = 0.35T AL = 2µH/turns2 BPEAK = 0.1T 394 . , , .
B = 0.2T
, 394: PV = 200kW/m3 394 200kHz 0.1. 0.2mW/mm3.
PCORE = PV · Ve
PCORE = 0.2
mW · 574mm3 = 115mW mm3
6
115mW RM5/I . .
NP =
VDRV · D MAX B · A e · f DRV
NP =
15V · 0.5 = 7.56turns 0.2T · 24.8mm 2 · 200kHz
8 . , 8 . . : WW = 4.7mm MLT = 24.9mm
, : dW = WW NP + 1 dW = 4.7 mm = 0.52mm 9
0.45mm : dW = 0.51mm W = 0.1062 m/mm
:
R W , DC = N P · MLT · W
R W ,DC = 8 · 24.9mm · 0.1062
m = 21.2m mm
:
D PEN =
7.6 f DRV
D PEN =
7.6 = 0.017cm 200000
Q=
0.83 · d W D PEN
Q=
0.83 · 0.506mm = 2.47 0.17mm
Q=2.5 RAC/RDC = 3, RAC = 3·21.2m = 63.6m, . .
LM = A L · N 2 I M ,P = I M 1 VDRV · D MAX = · 2 2 L M · f DRV D MAX 3
LM = 2 I M ,P =
µH · 82 = 128µH turns 2
1 15V · 0.5 · = 146mA 2 128µH · 200kHz 0.5 = 60mA 3
I M ,RMS = I M ,P ·
I M ,RMS = 146mA ·
:
PW = I 2 ,RMS · R AC M
PW = (60mA ) 2 · 63.6m = 0.2 mW
7
. , . , . , . , , , . . «» .
G A S G B S
8
F
. , . .
V IN = 156VDC V clamp = 129VDC I D2
Cclamp + Q2 IRF740 Lr 14uH 0.1uF D2 MUR860 Vo =130VDC
OUT2 6
UCC3580-4
Rload 85 Ohms
I D1
A
OUT1
4
PGND
D1 MUR860 Q1 IRFP350
5
: VDS1,off = VDS2,off = 285V ID1 = 2.7A TJ = 100° LR = 14uH - Q1 Q2 . (0V) VIN+VCLAMP Q1
UCC3580-4: OUT1 VDRV = 15V DMAX1 = 0.7 fDRV = 250kHz RHI1 = 20 RLO1= 10 OUT2 VDRV = 15V DMAX2 = 0.95 fDRV = 250kHz RHI2 = 33 RLO2= 33
9
, . IRFP350 QG1 = 135nC CGD1 = 148pF COSS1 = 391pF RG1,I = 1.2 VTH1= 3.2V VGS1,Miller = 4.2V IRF740 QG2 = 60nC CGD2 = 71pF COSS2 = 195pF RG2,I = 1.63 VTH2= 3.5V VGS2,Miller = 4.8V
. LR . , . : CR = COSS1+COSS2
dv I D1 dt RES C R
CR = 391pF+195pF = 586pF
dv 2 .7 A kV = 4 .6 dt RES 586pF µs
- ( RGATE = 0): VDRV - VGS, Miller dv = dt ON ( R G , I + R HI ) · CGD dv dt Q1,ON = 15V - 4.2 V kV = 3.4 (1.2 + 20) · 148pF µs
dv 15V - 4.8V kV = = 4.15 dt Q 2,ON (1.63 + 33) · 71pF µs
dv VTH = dt LIMIT ( R G ,I + R LO ) · CGD
dv 3.2 V kV = = 1.93 dt Q1, LIMIT (1.2 + 10) · 148pF µs dv 3.5V kV = = 1.42 dt Q 2, LIMIT (1.63 + 33) · 71pF µs
dv/dtLIMIT , , . .
Q2 IRF740 OUT2 6
UCC3580-4
OUT2 A
UCC3580-4
1:1 6 C1 C2
D
D R GATE1 4 Q1 IRFP350
RB 150 10K 1N5819 OUT1 4 R GATE2 5 D Q OFF A
OUT1
PGND
5
1N5819
Q OFF
10K
PGND
10
dv/dtLIMIT . 0.7V p-n QOFF. dv 3.2V - 0.7 V kV = 14 = dt Q1, LIMIT 1.2 · 148pF µs dv 3.5V - 0.7V kV = 24 = dt Q 2, LIMIT 1.63 · 71pF µs
RGATE. , dv/dtLIMIT. . 2.3kV/µs. . : VDRV - VGS, Miller dv , = dt ON ( R G ,I + R GATE + R HI ) · C GD :
R GATE =
VDRV - VGS , Miller - ( R HI + R G , I ) dv · CGD dt ON 15V - 4.8V - ( 33 + 1.6 ) = 27 kV 2.3 · 71pF µs
R GATE 1 =
15V - 4.2V - (20 + 1.2 ) = 10.5 kV 2.3 · 148pF µs
R GATE 1 =
. . . : LM = 100µH IM,P = 75mA D=0.5
, . VC1=0.65V VC2=0.65V. Q2 (VGATE=1.3V).
CC 2 =
QG 2 ( VDRV - VD , FW ) · D MAX + VC 2 · R GS · f DRV VC 2
CC2 =
60nC (15 - 0.7 V ) · 0.95 = 100nF + 0.65V 0.65 · 10k · 250kHz
C C1 =
Q G 2 ( VDRV - VD,FW ) · D VDRV · ( D 2 - D 3 ) , + + 2 VC1 VC1 · R GS · f DRV VC1 · 4 · L M · f DRV
D=0.68, 1 . :
=
2 · · f DRV · L M · R GS · CC1 2 · · f DRV · L M + R GS
=
2 · · 250kHz · 100µH · 10k · 235nF = 36µs 2 · · 250kHz · 100µH + 10k
UCC3850: PGATE = VDRV·(QG1+QG2) ·fDRV PGATE = 15V·(135nC+60nC) ·250kHz = 731mW 0.5 · 20 · 135nC · 15V · 250kHz = 162mW 20 + 10 + 1.2
POUT1 =
1 R HI 1 · · QG1 · VDRV · f DRV 2 R HI 1 + R GATE1 + R G!, I
POUT1 =
POUT 2 =
I2 R HI 2 1 · · Q G 2 · VDRV · f DRV + M , P · R HI 2 2 R HI 2 + R GATE 2 + R G 2 ,I 3
11
POUT 2 =
0.5 · 33 · 60nC · 15V · 250kHz (75mA) 2 + · 33 = 122mW 33 + 27 + 1.2 3
731mW , 284mW UCC3580. , . , RGS1 RGS2, . :
C DRV
( V - VD , FW ) · D MAX1 VDRV · ( D 2 1 - D 3 1 ) Q G1 + Q G 2 VDRV · D MAX 1 MAX MAX + + DRV + 2 VDRV · 4 · L M · f DRV VDRV · R GS 2 · f DRV VDRV · R GS1 · f DRV VDRV 135nC + 60nC 15V · 0.7 (15V - 0.7 V ) · 0.7 15V · ( 0.7 2 - 0.7 3 ) + + + = 291nF 1V 1V · 10k · 250kHz 1V · 10k · 250kHz 1V · 4 · 100µH · ( 250kHz ) 2
C DRV
12