???????(POL)

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???????(POL)

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Title: ???????(POL)

1
?????????

??????
????,?????????
???????(POL)
??
? ???,???????,????
? ???
? ????????????PWM?????????

2
?????????

??????
? ????
? ???????PWM??IC
? ??????? PWM??IC
? ??????? PWM??IC
? ?????
? Buck???Buck????? PWM??IC

3
?????????

2?????

?????? ??????
??? ?? ??,??????????
?? ? ??
???? ??,??,??? ?
????? ????,??????? ???,??????
??????? ?,?????????? ??,??????????
??? ? ??
???? ? ??
?? ? ??
4
Step-Down/Buck?????
??Buck??? 1 ?????????(???gt?????????????) 2 ???
L
Vin
Vo
R
C
5
Step-Down/Buck?????
????????
6
CCM??????

???????
IAVE gt ½ IRipple
?????????????
??????0
PWM??,????????
?????????

L
rc
Vin
Vo
d
R
C
PWM
????????,??????,???????,?????????????????????????
7
DCM???????

???????
IAVE lt ½ IRipple
?????(??)?????0
?????0??,????????????,???????0
????????????
??????????????

L
rc
???????
Vo
d
R
Vin
C
PWM
8
?????????

?????????????
Forced Continuous Mode
Pulse Skip Mode(??DCM)
Burst Mode

9
Forced Continuous Mode

?????????????????????????
?????????????????????????

????????????
?????????????????????,??????
????????????????

10
Pulse Skipping Mode

???????????????,????????????
??????????????????????????????????
?????????????????????????
????????????????
???????????Iq?????
??????????,?????????????

????????????,?????????????

11
Burst Mode Operation

?????????,???????????
???????Iq????
?disable???,?????????????????
????
?????????????????????????????

?????????

?????????????????????????
????????????????????
????????,??????????????????????

12
Burst Mode vs. Pulse Skip mode (Vout and IL)
Burst mode
Pulse skip mode

?????????????
?????????

????????????
????????

13
????????

Burst Mode?????????,??? Pulse Skip Mode,Forced
Continuous Mode??????

Forced Continuous Mode?????????,?? Pulse Skip
Mode, Burst Mode???????

14
??
Forced Continuous Pulse Skipping Burst
???? Okay Good Best
????? Best Good Okay
?? Best Good Okay
15
??????BUCK???
L
rc
Vo
d
R
Vin
C
PWM
R2
d
VFB
slope
Comp.
R1
dkVc
vc
Comparator
Vref
????????
???????A(s)
16
??????BUCK???

??
????????????
??
????????????,????????
?????????ESR???,??????????
????/?????????
???????????????,????????????

17
??????BUCK???
Rsense
L
rc
vo
Vo
d
R
Ki
Vin
C
PWM
d
R2
slope comp
C2
iL feedback
Kref(s)
EAIN
gm
R1
C1
veain
igm
Comparator
ITH
vc
Rth
Ro

???????????
??????????
????????
????????????????C

Cthp
Vref
Cth
Error Op-Amp
Compensation Network
18
??????BUCK???

??
??/??????
??????????
????????/?????????????????
??/???????
????
??
???????????,???????

???????????

?????????????????IC VC??????RC??,?????????????????
??????????????,??????????????? ?
??????????????????????????????????????????????????
??,?????????????????????????,?????????????????????
???,?????????????,????????????????????????????????
??????????
20
????????BUCK???
L
rc
vo
Vo
d
R
C
PWM
d
iL x Rds(on)
R2
C1
Kref(s)
EAIN
gm
R1
veain
igm
Comparator
ITH
vIth
Rth
Ro
Cthp
Vref
Cth
Error Op-Amp
Compensation Network
21
????????BUCK???
iL
Io
iL X Rds(on)
VIth
VIth iL X Rds(on)
????????
????????
??????
??????????????VO
22
?????????????
iL
Io
??????????
??????????
?????? ???0A??5A
?????? ???0A??5A
23