- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄10202 > SP3226EEY-L (Exar Corporation)IC TXRX RS232 ESD SD 16TSSOP PDF資料下載
參數(shù)資料
| 型號(hào)： | SP3226EEY-L |
| 廠商： | Exar Corporation |
| 文件頁(yè)數(shù)： | 4/23頁(yè) |
| 文件大?。?/td> | 0K |
| 描述： | IC TXRX RS232 ESD SD 16TSSOP |
| 標(biāo)準(zhǔn)包裝： | 95 |
| 類型： | 收發(fā)器 |
| 驅(qū)動(dòng)器/接收器數(shù)： | 1/1 |
| 規(guī)程： | RS232 |
| 電源電壓： | 3 V ~ 5.5 V |
| 安裝類型： | 表面貼裝 |
| 封裝/外殼： | 16-TSSOP（0.173"，4.40mm 寬） |
| 供應(yīng)商設(shè)備封裝： | 16-TSSOP |
| 包裝： | 管件 |
第1頁(yè)第2頁(yè)第3頁(yè)當(dāng)前第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)
2
Exar Corporation 48720 Kato Road, Fremont CA, 94538 50-668-707 www.exar.com
SP3224E,3225E,3226E,3227E_0_087
THEORy OF OPERATION
of5.5V,thechargepumpisenabled.Ifthe
output voltages exceed a magnitude of
5.5V,thechargepumpisdisabled.Thisos-
cillatorcontrolsthefourphasesofthevolt-
age shifting.A description of each phase
follows.
Highly Efficient Charge Pump
Thechargepumpisusedtogenerateposi-
tive and negative signal voltages for the
RS-232drivers.Thisenablesfullycompli-
antRS-232andV.28signalsfromasingle
3.0or5.5Vpowersupply.
Thechargepumpsusefourexternalcapac-
itorstoholdandtransferelectricalcharge.
The Exar patented design (US Patent
#5,306,954)usesauniqueapproachcom-
pared to older less efficient designs. The
pumps use a four–phase voltage shifting
techniquetoattainsymmetricalV+andV-
powersupplies.Anintelligentcontroloscil-
latorregulatestheoperationofthecharge
pump to maintain the proper voltages at
maximumefficiency.
Phase 1
Vss charge store and double: The posi-
tiveterminalsofcapacitorsC1andC2are
chargedfromVccwiththeirnegativetermi-
nals initially connected to ground. C1+ is
then connected to ground and the stored
charge from C1– is superimposed onto
C2–.SinceC2+isstillconnectedtoVcc
thevoltagepotentialacrosscapacitorC2is
now2xVcc.
Phase 2
Vss transfer and invert: Phase two con-
nectsthenegativeterminalofC2totheVss
storagecapacitorandthepositiveterminal
ofC2toground.Thistransfersthedoubled
andinverted(V–)voltageontoC4.Mean-
while, capacitor C1 charged from Vcc to
prepareitforitsnextphase.
Phase 3
Vddchargestoreanddouble:Phasethree
is identical to the first phase. The posi-
tiveterminalsofcapacitorsC1andC2are
chargedfromVccwiththeirnegativetermi-
nals initially connected to ground. C1+ is
then connected to ground and the stored
charge from C1– is superimposed onto
C2–. Since C2+ is still connected to Vcc
thevoltagepotentialacrosscapacitorC2is
now2xVcc.
Phase 4
Vdd transfer: The fourth phase connects
thenegativeterminalofC2togroundand
thepositiveterminalofC2totheVddstor-
age capacitor. This transfers the doubled
(V+)voltageontoC3.Meanwhile,capaci-
torC1chargedfromVcctoprepareitfor
itsnextphase.
TheExarchargepumpgeneratesV+and
V–independentlyfromVcc.Henceinano-
loadconditionV+andV-willbesymmetri-
cal. Older charge pump approaches gen-
erateV+andthenusepartofthatstored
chargetogenerateV-.Becauseofinherent
lossesthemagnitudeofV-willbesmaller
thanV+ontheseolderdesigns.
Under lightly loaded conditions the intelli-
gentpumposcillatormaximizesefficiency
byrunningonlyasneededtomaintainV+
andV–.Sinceinterfacetransceiversoften
spendmuchoftheirtimeatidlethispower-
efficientinnovationcangreatlyreducetotal
power consumption. This improvement is
madepossiblebytheindependentphase
sequenceoftheExarchargepump
design.
The clock rate for the charge pump typi-
callyoperatesatgreaterthan70kHzallow-
ing the pump to run efficiently with small
0.1μF capacitors. Efficient operation de-
pendsonrapidlycharginganddischarging
C1andC2,thereforecapacitorsshouldbe
mountedclosetotheICandhavelowESR
(equivalentseriesresistance).Inexpensive
surfacemountceramiccapacitors(suchas
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| VE-234-MX-F2 | CONVERTER MOD DC/DC 48V 75W |
| EN3P14F26X | CONN RCPT 14POS FEMALE PANEL #26 |
| VE-234-MX-F1 | CONVERTER MOD DC/DC 48V 75W |
| VE-262-CU-F4 | CONVERTER MOD DC/DC 15V 200W |
| CXS3106A1811P | CONN PLUG 5POS STRGHT PIN |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| SP3226EEY-L/TR | 功能描述:RS-232接口集成電路 INTELLIGENT +3-+5.5V RS-232 AUTO ONLINE RoHS:否 制造商:Exar 數(shù)據(jù)速率:52 Mbps 工作電源電壓:5 V 電源電流:300 mA 工作溫度范圍:- 40 C to + 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| SP3227ECA-L | 功能描述:RS-232接口集成電路 1MBPS +3V-5.5V RS232 W/AUTO ON-LINE RoHS:否 制造商:Exar 數(shù)據(jù)速率:52 Mbps 工作電源電壓:5 V 電源電流:300 mA 工作溫度范圍:- 40 C to + 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| SP3227ECA-L/TR | 功能描述:RS-232接口集成電路 1MBPS+3-+5.5V RS-232 AUTO ONLINE PLUS RoHS:否 制造商:Exar 數(shù)據(jù)速率:52 Mbps 工作電源電壓:5 V 電源電流:300 mA 工作溫度范圍:- 40 C to + 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| SP3227ECY-L | 功能描述:RS-232接口集成電路 1MBPS+3-+5.5V RS-232 AUTO ONLINE PLUS RoHS:否 制造商:Exar 數(shù)據(jù)速率:52 Mbps 工作電源電壓:5 V 電源電流:300 mA 工作溫度范圍:- 40 C to + 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| SP3227ECY-L/TR | 功能描述:RS-232接口集成電路 1MBPS+3-+5.5V RS-232 AUTO ONLINE PLUS RoHS:否 制造商:Exar 數(shù)據(jù)速率:52 Mbps 工作電源電壓:5 V 電源電流:300 mA 工作溫度范圍:- 40 C to + 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。