RT9171

2A Adjustable Low Dropout Positive Voltage RegulatorsGeneral DescriptionThe RT9171 is a high performance positive voltageregulator designed for applications requiring lowdropout at fully rated current. Additionally, theRT9171 provides excellent regulation over variationsin line and load. Outstanding features include lowdropout performance at rated current, fast transientresponse, internal current-limiting, and thermal-shutdown protection of the output device. TheRT9171 three-terminal regulator offers fixed 2.5Vand 3.3V output voltages, and adjustable voltageoptions available in TO-252 and TO-263 packages.Featuresz z z z z z Low Dropout, 1.6V Max.Full Current Rating Over Line and TemperatureFast Transient Response±1 % Output Voltage AccuracyAdjustable and Fixed Output VoltageTO- 252 and TO- 263 PackagesPin ConfigurationsPart NumberRT9171-󰂅󰂅CL(Plastic TO-252)123Pin Configurations1. ADJ/GND2. VOUT3. VINApplicationsz z z Active SCSI TerminationLow Voltage MicrocontrollersSwitching Power Supply Post-RegulatorRT9171-󰂅󰂅CM(Plastic TO-263)MARKOrdering InformationRT9171-󰂅󰂅 󰂅 󰂅Package typeL : TO-252M : TO-263Operating temperature rangeC: Commercial standardOutput voltageDefault : Adjustable25 : 2.5V output voltage33 : 3.3V output voltage1231. ADJ/GND2. VOUT3.VINTypical Application CircuitAdjustable Voltage RegulatorVIN = 5V RT9171VOUTVINADJVOUT = 3.3VVREFIADJR11201%R21951%+C110µFF+C222µFTANTR2VOUT = VREF (1+ ) + IADJ R2R1(1) C1 needed if device is far from filter capacitors.(2) C2 required for stability.DS9171-01 Feb. 2001www.richtek-ic.com.tw

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RT9171

Pin Description

Pin NameADJ / GNDVOUTVIN

Pin Function

Adjust Output or Ground PinOutput

Positive Power Input

Absolute Maximum Ratings

z z z z z

Input Voltage (VIN)

Operating Junction Temperature Range (TJ)Storage Temperature Range (TSTG)

Lead Temperature (Soldering) 10 seconds (TLEAD)Package Thermal ResistanceTO-252 (θJC)TO-263 (θJC)

9V

−40°C to 125°C−65°C to 150°C260°C15°C/W2°C/W

Electrical Characteristics

(TA=25°C, unless otherwise specified)

Parameter

Symbol

TJ = 25°C10mA < IOUT < 2A,1.6V < VIN - VOUT < 9V

Output Voltage

(1)(1)

Test Conditions

IOUT = 10mA, (VIN - VOUT) = 2V

MinTypMaxUnits

1.2381.2501.262

V

1.2251.2501.2702.4752.53.2673.3--------2.2------0.10.21.11.43572650.2

10--12052.5253.3330.30.41.21.6

V%%VAmAdBµAµA

Reference Voltage

(1)

RT9171

REF

RT9171-25RT9171-33

VOUT∆VOUT∆VOUTVIN-VOUTILIMIT

VIN = VOUT +2V, IOUT = 10mAIOUT = 10mA

1.6V ≤ VIN - VOUT to VIN = 9V(VIN − VOUT) = 2V, 0mA ≤ IOUT ≤ 2AIOUT = 100mAIOUT = 2AVIN = 5V(VIN - VOUT) = 2V

fRIPPLE = 120HZ , (VIN - VOUT) = 2V,VRIPPLE = 1VP-P

Line Regulation

Load Regulation Dropout Voltage Current Limit

(2)

Minimum Load CurrentRT9171Ripple RejectionAdjust Pin CurrentAdjust Pin Current Change

IADJ

10mA ≤ IOUT ≤ 1A, VIN = 5V

--

Notes: (1) Low duty cycle pulse testing with Kelvin connections.

(2) ΔVOUT and ΔVREF = 1%.

www.richtek-ic.com.tw DS9171-01 Feb. 2001

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RT9171

Package Information E L K B AF12 M3 I J H GC D SymbolsABCDEFGHIJKLMDimensions In MillimetersMin0.402.200.900.356.405.402.202.100.650.404.801.300.50Typ0.502.301.200.506.505.502.502.300.850.605.001.500.80Max0.602.401.500.656.655.652.802.501.050.805.201.701.10MinDimensions In InchesTyp0.19700.09060.04720.01970.25590.21650.09740.09060.03350.02360.19690.05900.0315Max0.02360.09450.05910.02560.26180.22240.11020.09840.04130.03150.20470.06690.04330.01570.08660.03540.01380.25200.21260.08660.08270.02560.01570.18900.05120.01973-Lead TO- 252 Plastic Surface Mount PackageDS9171-01 Feb. 2001 www.richtek-ic.com.tw

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RT9171

DBACUVEMARKL1b1L21e23bb232

1Symbols

DBEACUVL1L2bb1b2e

Dimensions In MillimetersMin9.6521.1438.1284.0641.143

6.223 Ref.7.620 Ref.

14.6052.2860.6601.1430.3052.286

15.8752.7940.9141.3970.5842.794Max10.6681.6769.6524.8261.397

Dimensions In InchesMin0.3800.0450.3200.1600.045

0.245 Ref.0.300 Ref.

0.5750.0900.0260.0450.0120.090

0.6250.1100.0360.0550.0230.110Max0.4200.0660.3800.1900.055

3-Lead TO- 263 Surface Mount

www.richtek-ic.com.tw DS9171-01 Feb. 2001

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RT9171

DS9171-01 Feb. 2001 www.richtek-ic.com.tw

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RT9171

RichTek Technology Corp.

Headquarter

6F, No. 35, Hsintai Road, Chupei CityHsinchu, Taiwan, R.O.C.

Tel: (8863)5510047 Fax: (8863)5537749

RichTek Technology Corp.

Taipei Office (Marketing)

4F-1, No. 127, Lane 235, Paochiao Road, Hsintien CityTaipei County, Taipei, R.O.C.

Tel: (8862)89191466 Fax: (8862)89191465Email: marketing@richtek-ic.com.tw

www.richtek-ic.com.tw DS9171-01 Feb. 2001

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