HV301/HV311
Design Information, cont’d.
Programming Inrush and ICB, continued:
Timing
Method 2: Inrush = 1/2 ICB
cti ec
btuicO
100mꢀ
1. ChttsOVICB
=
,VO.g.V2AV ⇒ VRSENSE = 50mΩ
RSENSE
GND
VIN
ꢀꢁUT
ꢀUꢀL
VOUT
50mv
50mꢀ
2. IipushV= V
,VO.g.V
=1A
ꢀIN
-48ꢀ
RSENSE
50mΩ
ꢀGATE
3. AddVctmꢂOisa atiVctmꢂtiOi sVfptmVga OV tVdpaaiVaf
iOcOssapyV tVpOducOVꢂOakaig.
START
ꢀRAMP
VRAMP
VGATE
ꢀGS(lam)
ꢀGATE
ꢀGS( h)
ꢀEE
TH
ILIM
PꢁR
90%
IIN
RISE
PWRGD
LIM
ec avO
PWRGD
aiec avO
Iia aelaze ati
FullVꢁi
a) s ep Vwa hV2iFVfptmVge OV tVstupcO
Lama aig
aa) aicpOesOV tV10iFVafViOOdOd
ThOV amaigVfuic atisVepOVdOfaiOdVbyV hOVftlltwaigVOque atis:
aaa) eddV1kVSOpaOsVpOsas tpVfptmVge OV tVceꢂeca tpVafViOOdOd
CRAMP
tSTART = 2.4
IRAMP
CRAMP
tTH = VGS(th)
IRAMP
tPOR = tSTART + tTH
CRAMP
tRISE
≈
⎛
gfs ⎜
⎝
⎞
IRAMP
0.9I
RSENSE
RFB
−
⎟
⎠
LIMIT
CLOAD
tLIMIT ≈ VIN
ILIMIT
CRAMP
tPWRGD = V − VGS(LIMIT) −1.2
(
)
INT
IRAMP
A092605
7
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