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KA278R33
Low Dropout Voltage Regulator
Features
•••••
2A / 3.3V Output low dropout voltage regulatorTO220 Full-Mold package (4PIN)
Overcurrent protection, Thermal shutdown
Overvoltage protection, Short-Circuit protectionWith output disable function
Description
The KA278R33 is a low-dropout voltage regulator suitable for various electronic equipments. It provides constant volt-age power source with TO-220 4 lead full mold package. Dropout voltage of KA278R33 is below 0.5V in full rated current(2A). This regulator has various function such as peak current protection, thermal shut down, overvoltage pro-tection and output disable function.
TO-220F-4L
1
1. Vin 2. Vo 3. GND 4. Vdis
Internal Block DiagramQ1Vin12VoTHERMAL SHUTDOWNOVERVOLTAGEPROTECTIONBANDGAP REFERENCE-+R1SOA PROTECTIONHIGH / LOWVdis4-+OUTPUTON / OFF1.4VSHORT-CIRCUITSHORTCIRCUIT PROTECTIONR23GNDRev.1.0.1
©2001 Fairchild Semiconductor Corporation
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KA278R33
Absolute Maximum Ratings
ParameterInput VoltageDisable Voltage Output Current Power Dissipation 1Power Dissipation 2 Junction TemperatureOperating Temperature
SymbolVinVdisIoPd1Pd2TjTopr
Value35352.01.515150-20 ~ +80
UnitVVAWW°C°C
Remark
---No HeatsinkWith Heatsink
--
Electrical Characteristics
(Vin=5V, Io=1.0A, Ta=25 °C, unless otherwise specified)
Parameter
Output VoltageLoad RegulationLine RegulationRipple Rejection RatioDropout VoltageDisable Voltage HighDisable Voltage LowDisable Bias Current HighDisable Bias Current LowQuiescent Current
SymbolVoRloadRlineRRVdropVdisHVdisLIdisHIdisLIq
5mA < Io < 2A4V < Vin < 10Vnote1Io = 2AOutput ActiveOutput DisabledVdis = 2.7VVdis = 0.4VIo = 0A
Conditions
-Min.3.22--45-2.0----Typ.3.30.10.555------Max.3.382.02.5-0.5-0.820-0.410
UnitV%%dBVVVµAmAmA
Note:
1.These parameters, although guaranteed, are not 100% tested in production.
2
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KA278R33
Typical Perfomance Characteristics
5.2550Output voltage Vo(V)4.503.753.002.251.500.7500 2 4 6 8 10RL=3.3ΩRL=8Quiescent current Iq(mA)4030200810RL=051015Input voltage Vin (V)Input voltage Vin (V)Figure 1.Output Voltage vs. Input VoltageFigure 2.Quiescent Current vs. Input Voltage
5.253.363.343.323.303.283.263.2400.511.522.533.22-25Output voltage Vo(V)4.503.753.002.251.500.750Output voltage Vo(V)0255075100125Disable voltage Vdis (V)TEMPERATURE Tj(oC)Figure 3.Output Voltage vs. Disable VoltageFigure 4.Output Voltage vs. Temperature(Tj)
Quiescent current Iq(mA)Dropout voltage Vdrop(V)10 80.60.50.4Io=2A0.31.5A0.20.10.5A0-251.0A 6 4 20-2502550751001250255075100125Junction temperature Tj(oC)Junction temperature Tj(oC)Figure 5.Quiescent Current vs. Temperature(Tj)Figure 6.Dropout Voltage vs. Junction Temperature
3
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KA278R33
Typical Perfomance Characteristics (continued)
20100Relative output voltage(%)Power dissipation PDD(W)80604015105200-2500255075100125TEMPERATURE Tj(aoC)01.02.03.04.05.06.0Output Current(A)Figure 7.Power Dissipation vs. Temperature(Ta)
Figure 8. Overcurrent Protection Characteristics
(Typical Value)
4
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KA278R33
Typical Application
Vin1+Vo2+3GND4VdisDisable SignalFigure 1.Application Circuit
•Ci is required if regulator is located an appreciable distance from power supply filter.•Co improves stability and transient response.(Co > 47µF)
5
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KA278R33
Mechanical Dimensions
Package
Dimensions in millimeters
TO-220F-4L
6
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KA278R33
Ordering Information
Product Number
KA278R33
PackageTO-220F-4L
Operating Temperature
-20°C to + 80°C
7
元器件交易网www.cecb2b.com
KA278R33
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein:
1.Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the user.
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2.A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.
