www.fairchildsemi.com A Adjustable/Fixed Low Dropout Linear Regulator Features Low dropout voltage Load regulation:.5% typical Trimmed current limit On-chip thermal limiting Standard SOT-223, TO-263, and TO-252 packages Three-terminal adjustable or fixed 2.5V, 2.85V, 3.3V, 5V Applications Active SCSI terminators High efficiency linear regulators Post regulators for switching supplies Battery chargers 5V to 3.3V linear regulators Motherboard clock supplies Description The and -2.5, -2.85, -3.3 and -5 are low dropout three-terminal regulators with A output current capability. These devices have been optimized for low voltage where transient response and minimum input voltage are critical. The 2.85V version is designed specifically to be used in Active Terminators for SCSI bus. Current limit is trimmed to ensure specified output current and controlled short-circuit current. On-chip thermal limiting provides protection against any combination of overload and ambient temperatures that would create excessive junction temperatures. Unlike PNP type regulators where up to % of the output current is wasted as quiescent current, the quiescent current of the flows into the load, increasing efficiency. The series regulators are available in the industrystandard SOT-223, TO-263 (D2PAK), and TO-252 (DPAK) power packages. Typical Applications V IN = 3.3V + V IN V OUT.5V at A + µf 22µF R ADJ 24Ω V OUT = V REF ( + R2/R) + I Adj R2 R2 24.9Ω -2.85 V IN = 5V V IN V + OUT + µf 22µF GND 2.85V at A REV..3.2 /6/3
Pin Assignments Front View Tab is V OUT Tab is V OUT Tab is V OUT 3 2 IN OUT ADJ/GND 2 3 2 3 4-Lead Plastic SOT-223 Θ JC = 5 C/W* ADJ/ GND IN 3-Lead Plastic TO-252 Θ JC = 3 C/W* ADJ/ GND OUT IN 3-Lead Plastic TO-263 Θ JC = 3 C/W* *With package soldered to.5 square inch copper area over backside ground plane or internal power plane., Θ JA can vary from 3 C/W to more than 5 C/W. Other mounting techniques may provide better thermal resistance than 3 C/W. Absolute Maximum Ratings Parameter Min. Max. Unit V IN 7.5 V Operating Junction Temperature Range 25 C Storage Temperature Range -65 5 C Lead Temperature (Soldering, sec.) 3 C 2 REV..3.2 /6/3
Electrical Characteristics Operating Conditions: V IN 7V, T J = 25 C unless otherwise specified. The denotes specifications which apply over the specified operating temperature range. Parameter Conditions Min. Typ. Max. Units Reference Voltage, V 3 REF.5V (V IN - V OUT ) 5.75V,.225.25.275 V ma I OUT A (-2%) (+2%) Output Voltage ma I OUT A -2.5, 4V V IN 7V -2.85, 4.35V V IN 7V -3.3, 4.8V V IN 7V -5, 6.5V V IN 7V Notes:. See thermal regulation specifications for changes in output voltage due to heating effects. Load and line regulation are measured at a constant junction temperature by low duty cycle pulse testing. 2. Line and load regulation are guaranteed up to the maximum power dissipation (8W). Power dissipation is determined by input/output differential and the output current. Guaranteed maximum output power will not be available over the full input/ output voltage range. 3. only. 2.45 2.793 3.234 4.9 2.5 2.85 3.3 5. 2.55 2.97 3.366 5. Line Regulation,2 (V OUT +.5V) V IN 7V, I OUT = ma.5.2 % Load Regulation,2 (V IN V OUT ) = 2V, ma I OUT A.5.5 % Dropout Voltage V REF = %, I OUT = A..2 V Current Limit (V IN V OUT ) = 2V..5 A Adjust Pin Current, I 3 Adj 35 2 µa Adjust Pin Current Change 3.5V (V IN V OUT ) 5.75,.2 5 µa ma I OUT A Minimum Load Current.5V (V IN V OUT ) 5.75 ma Quiescent Current V IN = V OUT +.25V 4 3 ma Ripple Rejection f = 2Hz, C OUT = 22µF Tantalum, (V IN V OUT ) = 3V, I OUT = A 6 72 db Thermal Regulation T A = 25 C, 3ms pulse.4.2 %/W Temperature Stability.5 % Long-Term Stability T A = 25 C, hrs..3. % RMS Output Noise T A = 25 C, Hz f khz.3 % (% of V OUT ) Thermal Resistance, Junction SOT-223 5 C/W to Case TO-252, TO-263 3 C/W Thermal Shutdown Junction Temperature 55 C Thermal Shutdown Hysteresis C V V V V REV..3.2 /6/3 3
Typical Performance Characteristics DROPOUT VOLTAGE (V).5..4.3.2...9.8.7.6.5 T J = 25 C T J = C T J = 25 C -.2.2.4.6.8. -75-5 -25 25 5 75 25 5 75 OUTPUT CURRENT (A) DROPOUT VOLTAGE DEVIATION (%).5 -.5 -. -.5 I = A Figure. Dropout Voltage vs. Output Current Figure 2. Load Regulation vs. Temperature REFERENCE VOLTAGE (V).25 3.7.245 3.65 V OUT SET WITH % RESISTORS V OUT = 3.6V.24.235.23.225.22.25.2.25.2 3.6 3.55 3.5 3.45 3.4 3.35 3.3 3.25 3.2 V OUT = 3.3V Note:. Only -75-5 -25 25 5 75 25 5 75-75 -5-25 25 5 75 25 5 75 Figure 3. Reference Voltage vs. Temperature REFERENCE VOLTAGE (V) Figure 4. Output Voltage vs. Temperature MINIMUM LOAD CURRENT (ma) 5 4 3 2-75 -5-25 25 5 75 25 5 75 Figure 5. Minimum Load Current vs. Temperature ADJUST PIN CURRENT (µa) 9 Note:. Only 8 7 6 5 4 3 2-75 -5-25 25 5 75 25 5 75 Figure 6. Adjust Pin Current vs. Temperature 4 REV..3.2 /6/3
Typical Performance Characteristics (continued) 2. 9 SHORT-CIRCUIT CURRENT (A).75.5.25. -75-5 -25 25 5 75 25 5 75 RIPPLE REJECTION (db) 8 7 6 5 4 3 2 (V IN - V OUT ) = 3V.5 < V RIPPLE < 2V I OUT = A K K K FREQUENCY (Hz) Figure 7. Short-Circuit Current vs. Temperature Figure 8. Ripple Rejection vs. Frequency 7.5 POWER (W) 5 TO-252 & TO-263 2.5 SOT-223 25 45 65 85 5 25 CASE TEMPERATURE ( C) Figure 9. Maximum Power Dissipation REV..3.2 /6/3 5
Mechanical Dimensions 4-Lead SOT-223 Package Symbol Inches Millimeters Min. Max. Min. Max. Notes A.7 A.8 B.25.33 c.9 D.248.264 E.3.48.8 4.8.64.84 2.29 6.3 6.7 3.3 3.7 e.5.24 2.95 3.5 F.33.4.84.4 H.264.287 6.7 7.29 I.2.3 J K 6 6 L.8.4.23.8 M 6 6 N..4.25.36 D e K H E A J M N B I L A c F 6 REV..3.2 /6/3
Mechanical Dimensions 3-Lead TO-252 Package 6.73 6.35 5.46 5.2 A 6. MIN L3 4 6.5 MIN D.2.84 6.25 C 2 3 3 3. MIN (.59).89.54.25 M A M C 4.57.4.78 2.29.4 MIN 2.3 4.8 LAND PATTERN RECOMMENDATION B SEE NOTE D E 4 2.38 2.8.58.48 D SEE DETAIL A.4 9.4 3 2. B.6.48 GAGE PLANE.78.4 2.9 DETAIL A (ROTATED 9 SCALE 2X.27 MAX.5 SEATING PLANE (.54) NOTES: UNLESS OTHERWISE SPECIFIED A) ALL DIMENSIONS ARE IN MILLIMETERS. B) THIS PACKAGE CONFORMS TO JEDEC, TO-252, ISSUE C. VARIATION AA & AB, DATED NOV. 999. C) DIMENSIONING AND TOLERANCING PER ASME Y4.5 994. D) HEAT SINK TOP EDGE COULD BE IN CHAMFERED CORNERS OR EDGE PROTRUSION. E) DIMENSIONS L3, D, E & D TABLE: L3 D E D OPTION AA OPTION AB.89.27.52 2.3 5.97 6.22 5.33 5.59 4.32 MIN 3.8 MIN 5.2 MIN 4.57 MIN REV..3.2 /6/3 7
Mechanical Dimensions 3-Lead TO-263 Package Symbol Inches Millimeters Min. Max. Min. Max. A.6.9 4.6 4.83 b.2.36.5.9 b2.49.5.25.3 c2.45.55.4.4 D.34.38 8.64 9.65 E.38.45 9.65.29 e. BSC 2.54 BSC L.575.625 4.6 5.88 L.9. 2.29 2.79 L2.55.4 R.7.9.43.78 α 8 8 Notes Notes:. Dimensions are exclusive of mold flash and metal burrs. 2. Standoff-height is measured from lead tip with ref. to Datum -B-. 3. Foot length is measured with ref. to Datum -A- with lead surface (at inner R). 4. Dimensiuon exclusive of dambar protrusion or intrusion. 5. Formed leads to be planar with respect to one another at seating place -C-. E @PKG/ @HEATSINK L2 c2 L D E-PIN b2 R (2 PLCS) L e b -A- -B- -C- A 8 REV..3.2 /6/3
Ordering Information Product Number Output Package DT Adjustable TO-252 in tape and reel M Adjustable TO-263 MT Adjustable TO-263 in tape and reel ST Adjustable SOT-223 in tape and reel D25T 2.5 volt TO-252 in tape and reel M25 2.5 volt TO-263 M25T 2.5 volt TO-263 in tape and reel S25T 2.5 volt SOT-223 in tape and reel M285 2.85 volt TO-263 M285T 2.85 volt TO-263 in tape and reel S285T 2.85 volt SOT-223 in tape and reel D33T 3.3 volt TO-252 in tape and reel M33 3.3 volt TO-263 M33T 3.3 volt TO-263 in tape and reel S33T 3.3 volt SOT-223 in tape and reel D5T 5 volt TO-252 in tape and reel M5 5 volt TO-263 M5T 5 volt TO-263 in tape and reel S5T 5 volt SOT-223 in tape and reel 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:. 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. 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. www.fairchildsemi.com /6/3.m 5 Stock#DS37 2 Fairchild Semiconductor Corporation