LT1585-1.5/LT1585A-1.5 Fixed 1.5V, 4.6A and 5A Low Dropout, Fast Response + GTL Regulators FEATURES DESCRIPTIO n Fast Transient Response The LT 1585-1.5/LT1585A-1.5 are low dropout, 3-termi- n Guaranteed Dropout Voltage at Multiple Currents nal regulators with 4.6A and 5A output current capability n Load Regulation: 0.05% Typ respectively, and a fixed 1.5V output voltage. The designs n Trimmed Current Limit are optimized for low voltage applications where transient n On-Chip Thermal Limiting response and minimum input voltage are critical. Similar to the LT1084, they have lower dropout and faster transient U response. These improvements make them ideal for low APPLICATIO S voltage microprocessor applications, especially as the n + GTL Power Supply + regulator in an Intel processor GTL supply. n Low Voltage Logic Supplies Current limit is trimmed to ensure specified output current n Battery-Powered Circuitry and controlled short-circuit current. On-chip thermal lim- iting provides protection against any combination of over- load that creates excessive junction temperatures. The LT1585-1.5/LT1585A-1.5 are available in the through- hole 3-pin TO-220 power package and 3-pin plastic DD. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIO + Intel Processor GTL Supply V = 1.5V TT LT1585A-1.5 5A 3.3V V V IN OUT C7 TO R1 GND C12 R5 R7 R8 R6 R3 75 1F V V REF 100 100 100 100 REF 75 + C1, C2 + C3 TO C6 100F 100F C13 C14 R4 R2 10V 10V 0.1F 0.1F 150 150 RX RX TX Q1 TX Q2 RX RX NOTE: LTC RECOMMENDS CENTRALLY LOCATING THE LT1585A-1.5 TO MINIMIZE TX TX Q3 Q4 V DISTRIBUTION DROPS AND USING TT SEPARATE V GENERATORS AT EACH REF BUS END 1585-1.5 TA01 142 TOTAL SIGNAL LINES 1 U ULT1585-1.5/LT1585A-1.5 ABSOLUTE MAXIMUM RATINGS (Note 1) V ............................................................................ 7V Storage Temperature Range ................ 65 C to 150 C IN Operating Junction Temperature Range Lead Temperature (Soldering, 10 sec)................. 300 C Control Section .................................. 0 C to 125 C Power Transistor ................................ 0 C to 150 C PRECONDITIONI G 100% Thermal Limit Functional Test PACKAGE/ORDER INFORMATION ORDER PART FRONT VIEW ORDER PART FRONT VIEW *WITH PACKAGE NUMBER NUMBER SOLDERED TO 0.5 3 V 3 V IN IN SQUARE INCH COPPER TAB TAB IS AREA OVER BACKSIDE 2 V IS 2 V OUT OUT LT1585CM-1.5 OUTPUT LT1585CT-1.5 GROUND PLANE OR OUTPUT 1 GND 1 GND INTERNAL POWER PLANE. LT1585ACM-1.5 LT1585ACT-1.5 q CAN VARY FROM JA 20 C/W TO > 40 C/W T PACKAGE M PACKAGE WITH OTHER MOUNTING 3-LEAD PLASTIC TO-220 3-LEAD PLASTIC DD TECHNIQUES q = 30 C/W* q = 50 C/W JA JA Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the specified operating temperature range, otherwise specifications are at T = 25 C. A PARAMETER CONDITIONS MIN TYP MAX UNITS Output Voltage (Note 4) V = 5V, T = 25 C, I = 0mA 1.485 (1%) 1.5 1.515 (+1%) V IN J OUT 3V V 7V, 0mA I I l 1.470 (2%) 1.5 1.530 (+2%) V IN OUT FULL LOAD Line Regulation (Notes 2, 3) 3V V 7V, I = 0mA 0.005 0.2 % IN OUT Load Regulation V = 5V, T = 25 C, 0mA I I 0.05 0.3 % IN J OUT FULL LOAD (Notes 2, 3, 4) l 0.05 0.5 % Dropout Voltage (Note 4) D V = 1%, I = I l 1.200 1.400 V OUT OUT FULL LOAD Current Limit LT1585-1.5, (V V ) = 5.5V l 4.60 5.25 A IN OUT LT1585A-1.5, (V V ) = 5.5V l 5.00 6.00 A IN OUT Quiescent Current V = 5V l 713 mA IN Ripple Rejection (Note 4) f = 120Hz, C = 25m F Tant., V = 4.5V, I = I l 60 72 dB OUT IN OUT FULL LOAD Thermal Regulation T = 25 C, 30ms Pulse 0.004 0.02 %/W A Temperature Stability l 0.5 % Long-Term Stability T = 125 C, 1000 Hrs. 0.03 1.0 % A RMS Output Noise T = 25 C, 10Hz f 10kHz 0.003 % A (% of V ) OUT Thermal Resistance T Package: Control Circuitry/Power Transistor 0.7/3.0 C/W Junction to Case M Package: Control Circuitry/Power Transistor 0.7/3.0 C/W Note 1: Absolute Maximum Ratings are those values beyond which the life the LT1585A-1.5). Power dissipation is determined by input/output of the device may be impaired. differential and the output current. Guaranteed maximum output power will not be available over the full input/output voltage range. Note 2: See thermal regulation specifications for changes in output voltage due to heating effects. Load and line regulation are measured at a constant Note 4: I is defined as the maximum value of output load current FULL LOAD junction temperature by low duty cycle pulse testing. as a function of input-to-output voltage. I is equal to 4.6A for the FULL LOAD LT1585-1.5 and 5A for the LT1585A-1.5. The LT1585-1.5/LT1585A-1.5 Note 3: Line and load regulation are guaranteed up to the maximum have constant current limit with changes in input-to-output voltage. power dissipation (25W for the LT1585-1.5 in T package and 27.5W for 2 U W U U U U U WWW