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V
交流
V
USB
V
输出
V
BAT
dppm 模式
usb declared 不 呈现
交流 是 应用 (usb 模式)
交流 hits usb (iset2) 限制
V
交流
V
USB
V
输出
V
BAT
charging (步伐) followed 用 承担 完毕
BAt 管脚 电容 discharging 至 refresh 门槛
bq24030,bq24031,bq24032,
bq24032a,bq24035,bq24038,bq24039
SLUS618C–AUGUST2004–REVISEDJUNE2005
5.4v;channel2(ch2)v
(usb)
=5v;channel3(ch3)v
输出
;outputcurrent,i
输出
=0.25a;channel4(ch4)v
BAT
=3.5v;andi
(pgm-chg)
=1a.theusbsourceisremoved(2
nd
div)andtheoutputdropstothebatteryvoltage
(declaresusbbad,4
th
div)andswitchestoac(inusbmode)andrecoverssimilartothefigurethatisswitching
tousbpower.thispowertransferoccurredwithpsellow,whichmeansthattheacinputisregulatedasifit
wereausb.
figure10.removeusb–pwrxferfromusbtoac
Figure11illustrateswhenthebatteryisabsent,powertransferstousb;psel=h;channel1(ch1)vac=5.4
v;channel2(ch2)v
(usb)
=5v;channel3(ch3)v
输出
;outputcurrent,i
输出
=0.25a;channel4(ch4)v
BAT
;
I
(pgm-chg)
=1a.notethesaw-toothwaveformduetocyclingbetweenchargedoneandrefresh(newcharge).
figure11.batteryabsent–pwrxfertousb
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