www.德州仪器.com
APPLICATIONINFORMATION
adjustingtheoutputvoltageofthepth08080wwide-outputadjustpowermodules
R = 10 k x
设置
0
.
8
9
1
V
V - 0.9 v
输出
- 1.82 k
V
I
地
地
V
O
R
设置
0.05 w
1%
PTH08080W
2
4
3
1
5
V
Adj
O
地
Inhibit
V
I
V
O
C
I
C
O
d1 (看 便条 3)
PTH08080W
SLTS235A–FEBRUARY2005–REVISEDMARCH2005
这
V
O
调整
控制(pin4)setstheoutputvoltageofthepth08080wproduct.theadjustmentrangeisfrom
0.9vto5.5v.theadjustmentmethodrequirestheadditionofasingleexternalresistor,r
设置
,thatmustbe
connecteddirectlybetweenthe
V
O
调整
和
地
(pin2).table1givesthestandardexternalresistorfora
numberofcommonbusvoltages,alongwiththeactualvoltagetheresistanceproduces.
forotheroutputvoltages,thevalueoftherequiredresistorcaneitherbecalculatedusingthefollowingformula,
orsimplyselectedfromtherangeofvaluesgivenintable2.figure10showstheplacementoftherequired
电阻.
table1.standardvaluesofr
设置
forCommonOutput
电压
V
O
R
设置
V
O
(必需的)(standardvalue)(真实的)
5V348
Ω
5.010v
3.3v
(1)
1.87k
Ω
3.315v
2.5v
(1)
3.74k
Ω
2.503v
2v6.19k
Ω
2.012v
1.8v8.06k
Ω
1.802v
1.5v13.0k
Ω
1.501v
1.2v27.4k
Ω
1.205v
1v86.6k
Ω
1.001v
0.9vopen0.9v
(1)theminimuminputvoltageis4.5vor(v
O
+2)v,whicheveris
更好.themaximuminputvoltageis18vor(v
O
*10)v,
whicheverislesser.
(1)a0.05-wratedresistormaybeused.thetoleranceshouldbe1%,withatemperaturestabilityof100ppm/
°
c(或者
更好的).placetheresistorasclosetotheregulatoraspossible.connecttheresistordirectlybetweenpins4and2
usingdedicatedpcbtraces.
(2)neverconnectcapacitorsfrom
V
O
调整
toeither
地
或者
V
O
.anycapacitanceaddedtothe
V
O
调整
pinaffectsthe
stabilityoftheregulator.
(3)theprotectiondiode,d1,isrequiredwhenevertheoutputvoltagesetpointisadjustedto5.25v(orhigher)andv
I
是
16vorgreater.
figure10.v
O
AdjustResistorPlacement
7
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