2576 ,5-AmpAdjustableRegulatorsElectrical CharacteristicsSymbol Parameter Conditions LM338 UnitsMin Typ MaxV Reference Voltage 3V ..
25AA256I/SN , 256K SPI Bus Serial EEPROM
25AA256-I/SN , 256K SPI Bus Serial EEPROM
25AA256T-I/SN , 256K SPI Bus Serial EEPROM
25C02 , 1K/2K/4K/8K/16K SPI Serial CMOS E2PROM
25C04 , 1K/2K/4K/8K/16K SPI Serial CMOS E2PROM
2SA1461-T2B ,Silicon transistorELECTRICAL CHARACTERISTICS (Ta = 2
CHARACTERISTIC SYMBOL
Collector Cutoff Current ICBO.
Emit ..
2SA1462 ,HIGH SPEED SWITCHING PNP SILICON EPITAXIAL TRANSISTOR MINI MOLDELECTRICAL CHARACTERISTICS (Ta = 25 °C)
CHARACTERISTIC SYMBOL _ . . . TEST CONDITIONS
(q Collec ..
2SA1462-T1B ,HIGH SPEED SWITCHING PNP SILICON EPITAXIAL TRANSISTOR MINI MOLDFEATURES
E
E 0 High Speed Switching : ton =9.0 ns TYP.
+0.1 E . I toff=19.0 ns TYP.
E .. . . ..
2SA1462-T2B ,Silicon transistor_ HIGH SPEED SWITCHING
PNP SILICON EPITAXIAL TRANSISTOR
MINI MOLD
NEC V f - t-----_- W m SILIE ..
2SA1462-T2B ,Silicon transistorELECTRICAL CHARACTERISTICS (Ta = 25 °C)
CHARACTERISTIC SYMBOL _ . . . TEST CONDITIONS
(q Collec ..
2SA1462-T2B ,Silicon transistorFEATURES
E
E 0 High Speed Switching : ton =9.0 ns TYP.
+0.1 E . I toff=19.0 ns TYP.
E .. . . ..
2576
5-AmpAdjustableRegulators
LM138/LM338
5-Amp Adjustable Regulators
General DescriptionThe LM138 seriesof adjustable 3-terminal positive voltage
regulatorsis capableof supplyingin excessof5A overa
1.2Vto 32V output range. Theyare exceptionally easyto
useand require only2 resistorstosetthe output voltage.
Careful circuit designhas resultedin outstanding loadand
line regulation— comparableto many commercial power
supplies.The LM138 familyis suppliedina standard 3-lead
transistor package. unique featureofthe LM138 familyis time-dependentcur-
rent limiting.The current limit circuitry allows peak currentsupto12Atobe drawn fromthe regulatorfor short periods time. This allowsthe LM138tobe used with heavy tran-
sient loadsand speeds start-up under full-load conditions.
Under sustained loading conditions,the current limitde-
creasestoa safe value protectingthe regulator. Alsoin-
cludedonthe chipare thermal overload protectionand safe
area protectionforthe power transistor. Overload protection
remains functional evenifthe adjustmentpinis accidentally
disconnected.
Normally,no capacitorsare needed unless thedeviceis situ-
ated more than6 inches fromthe input filter capacitorsin
which casean input bypassis needed.An output capacitor
canbe addedto improve transient response, while bypass-
ingthe adjustmentpinwill increasethe regulator’s ripplere-
jection.
Besides replacing fixed regulatorsor discrete designs,the
LM138is usefulina wide varietyof other applications. Since
the regulatoris “floating”and sees onlythe input-to-output
differential voltage, suppliesof several hundred voltscanbe
regulatedas longasthe maximum input tooutput differentialnot exceeded, i.e.,donot short-circuit outputto ground.
Thepart numbers inthe LM138series which havea Ksuffix
are packagedina standard SteelTO-3 package, while those
withaT suffixare packagedina TO-220 plastic package.
The LM138is ratedfor −55˚C≤TJ ≤+150˚C,and theLM338 ratedfor0˚C≤TJ≤ +125˚C.
Features Guaranteed7A peak output current Guaranteed5A output current Adjustable output downto 1.2V Guaranteed thermal regulation Current limit constant with temperatureP+ Product Enhancement tested Outputis short-circuit protected
Applications Adjustable power supplies Constant current regulators Battery chargers
Connection Diagrams (See Physical Dimension sectionfor further information)
(TO-3 STEEL)
Metal Can PackageDS009060-30
Bottom View
Order Number LM138K STEELor LM338K STEEL
SeeNS Package Number K02A
(TO-220)
Plastic PackageDS009060-31
Front View
Order Number LM338T
SeeNS Package Number T03BMay 1998
LM138/LM338
5-Amp
Adjustable
Regulators 1999 National Semiconductor Corporation DS009060
