LT1585A/LT1585A-3.3 5A Low Dropout Fast Response Positive Regulators Adjustable and Fixed FEATURES DESCRIPTIO Fast Transient Response The LT 1585A/LT1585A-3.3 are low dropout 3-terminal Guaranteed Dropout Voltage at Multiple Currents regulators with 5A output current capability. Design has Load Regulation: 0.05% Typ been optimized for low voltage applications where tran- Trimmed Current Limit sient response and minimum input voltage are critical. On-Chip Thermal Limiting Similar to the LT1084 family, these regulators feature Standard 3-Pin TO-220 Power Package lower dropout voltage and faster transient response. These improvements make them ideal for low voltage U microprocessor applications requiring a regulated 2.5V to APPLICATIO S 3.6V output with an input supply below 7V. Pentium Processor Supplies TM Current limit is trimmed to ensure specified output current PowerPC Supplies and controlled short-circuit current. On-chip thermal lim- Other 2.5V to 3.6V Microprocessor Supplies iting provides protection against any combination of over- Low Voltage Logic Supplies load that would create excessive junction temperatures. Battery-Powered Circuitry Post Regulator for Switching Supply The LT1585A/LT1585A-3.3 are available in the industry standard 3-pin TO-220 power package. LT1585ACT Adjustable , LTC and LT are registered trademarks of Linear Technology Corporation. LT1585ACT-3.3 3.3V Fixed Pentium is a registered trademark of Intel Corporation. PowerPC is a trademark of IBM Corporation. TYPICAL APPLICATIO 3.3V, 5A Regulator Dropout Voltage vs Output Current 1.5 1.4 3.3V LT1585A-3.3 V 4.75V IN 5A 1.3 + + C1 C2* 1.2 10F 100F 1.1 1585A TA01 1.0 * REQUIRED FOR STABILITY 0.9 NOTE: MICROPROCESSOR APPLICATIONS WITH LOAD TRANSIENTS OF 3.8A REQUIRE 0.8 OUTPUT DECOUPLING CAPACITANCE >1300F ON FIXED VOLTAGE PARTS TO ACHIEVE 0.7 < 50mV OF DEVIATION FROM NOMINAL OUTPUT. CONSULT FACTORY FOR DETAILS 0.6 0.5 0 I FULL LOAD OUTPUT CURRENT (A) LT1585A TA02 1585afa 1 INPUT/OUTPUT DIFFERENTIAL (V) U ULT1585A/LT1585A-3.3 ABSOLUTE MAXIMUM RATINGS Storage Temperature Range ................. 65C to 150C V ............................................................................. 7V IN Lead Temperature (Soldering, 10 sec).................. 300C Operating Junction Temperature Range Control Section ................................... 0C to 125C PRECONDITIONI G Power Transistor ................................. 0C to 150C 100% Thermal Limit Functional Test PACKAGE/ORDER INFORMATION FRONT VIEW FRONT VIEW ORDER PART ORDER PART NUMBER NUMBER 3 V 3 V IN IN TAB IS TAB IS LT1585ACT LT1585ACT-3.3 2 V 2 V OUT OUT V V OUT OUT 1 ADJ 1 GND T PACKAGE T PACKAGE 3-LEAD PLASTIC TO-220 3-LEAD PLASTIC TO-220 = 50C/W, = 3C/W = 50C/W, = 3C/W JA JC JA JC Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The denotes specificatons which apply over the specified temperature range, otherwise specifications are at T = 25C. A PARAMETER CONDITIONS MIN TYP MAX UNITS Reference Voltage LT1585A (V V ) = 3V, T = 25C, I = 10mA 1.238 (1%) 1.250 1.262 (+1%) V IN OUT J OUT 1.5V (V V ) 5.75V, 10mA I 5A 1.225 (2%) 1.250 1.275 (+2%) V IN OUT OUT Output Voltage LT1585A-3.3 V = 5V, T = 25C, I = 0mA 3.267 (1%) 3.300 3.333 (+1%) V IN J OUT 4.75V V 7V, 0mA I 5A 3.235 ( 2%) 3.300 3.365 (+2%) V IN OUT Line Regulation LT1585A 2.75V V 7V, I = 10mA IN OUT (Notes 1, 2) LT1585A-3.3 4.75V V 7V, I = 0mA IN OUT 0.005 0.2 % Load Regulation LT1585A (V V ) = 3V, T = 25C, 10mA I I N OUT J OUT FULL LOAD (Notes 1, 2, 3) LT1585A-3.3 V = 5V, T = 25C, 0mA I I 0.05 0.3 % IN J OUT FULL LOAD 0.05 0.5 % Dropout Voltage LT1585A V = 1%, I = 3A REF OUT LT1585A-3.3 V = 1%, I = 3A OUT OUT 1.150 1.300 V LT1585A V = 1%, I = 5A REF OUT LT1585A-3.3 V = 1%, I = 5A OUT OUT 1.200 1.400 V Current Limit LT1585A (V V ) = 5.5V IN OUT (Note 3) LT1585A-3.3 (V V ) = 5.5V IN OUT 5.0 6.0 A Adjust Pin Current LT1585A 55 120 A Adjust Pin Current LT1585A 1.5V (V V ) 5.75V, 10mA I I 0.2 5 A IN OUT OUT FULL LOAD Change (Note 3) Minimum LT1585A 1.5V (V V ) 5.75V 210 mA IN OUT Load Current Quiescent Current LT1585A-3.3 V = 5V 813 mA IN 1585afa 2 U W U U U U U WWW