LTC1143/LTC1143L LTC1143L-ADJ Dual High Efficiency SO-16 Step-Down Switching Regulator Controllers FEATURES DESCRIPTION n The LTC1143 series is a dual step-down switching regulator Dual Outputs TM controller featuring automatic Burst Mode operation to LTC1143, LTC1143L: 3.3V, 5V maintain high efficiencies at low output currents. This LTC1143L-ADJ: Dual Adjustable n device is composed of two separate regulator blocks, Very High Efficiency: Over 95% Possible each driving an external power MOSFET at switching n Current Mode Operation for Excellent Line and Load frequencies up to 400kHz using a constant off-time current Transient Response mode architecture. Both fixed and adjustable voltages are n High Efficiency Maintained over Three Decades of available. Output Current n Low Standby Current at Light Loads: 160A/Output The operating current level for both regulators is user- n Logic-Controlled Shutdown (LTC1143, LTC1143L) programmable via an external current sense resistor. n Wide V Range: 3.5V to 16V Wide input supply range allows operation from 4V to 14V IN (LTC1143L, LTC1143L-ADJ) (16V maximum). The LTC1143L and LTC1143L-ADJ n extend operation to V = 3.5V. 100% duty cycle provides Very Low Dropout Operation: 100% Duty Cycle IN n low dropout regulation limited only by the R of the Available in Narrow 16-Pin SO Package DS(ON) external MOSFET and resistance of the inductor and U current sense resistor. APPLICATIONS The LTC1143 series is ideal for applications requiring dual n Personal Digital Assistants output voltages with high conversion efficiencies over a n Notebook and Palmtop Computers wide load current range in a small amount of board space. n Battery-Operated Digital Devices n Portable Instruments , LTC and LT are registered trademarks of Linear Technology Corporation. n Burst Mode is a trademark of Linear Technology Corporation. DC Power Distribution Systems V TYPICAL APPLICATION IN 4V TO 14V C IN2 C + IN1 22F 22F 0.22F 0.22F 25V 25V 2 13 5 2 P1A P1B V V IN1 IN2 4 12 L1 L2 R R SENSE1 SENSE2 P-DRIVE 1 P-DRIVE 2 27H 27H 0.05 0.05 V V OUT1 OUT2 3.3V/2A 1 9 2.5V/2A + + SENSE 1 SENSE 2 1000pF LTC1143L-ADJ 1000pF SENSE 1 SENSE 2 C OUT1 R4 R2 16 8 C D2 OUT2 D1 + 220F 82.5k 49.9k 220F MBRS320T3 MBRS320T3 10V 1% 1% 10V V 2 V FB2 FB1 2 10 2 R1 R3 GND1 C I I C GND2 T2 T1 TH1 TH2 49.9k 100pF 49.9k 100pF 3 14 15 7 611 1% 1% R R C1 C2 1k 1k C C C C T1 C1 C2 T2 3300pF L1, L2: SUMIDA CDRH125-270 300pF 3300pF 300pF P1: SILICONIX Si4953DY/FAIRCHILD NDS8947 R R : DALE WSL-2010-.05 SENSE1, SENSE2 1143 F01 Figure 1. High Efficiency Dual 3.3V/2.5V Regulator 1 + + U ULTC1143/LTC1143L LTC1143L-ADJ ABSOLUTE MAXIMUM RATINGS Input Supply Voltage (Pins 5,13) ............... 16V to 0.3V V Current (LTC1143L-ADJ, Pins 2, 10) ............... 1mA FB Continuous Output Current (Pins 4,12) ................ 50mA Operating Temperature Range Sense Voltages (Pins 1, 8, 9, 16) Ambient .................................................. 0C to 70C V 12.7V .......................................... 13V to 0.3V Extended Commercial (Note 4) ...........40C to 85C IN V < 12.7V .............................. (V + 0.3V) to 0.3V Junction Temperature (Note 1)............................. 125C IN IN Shutdown Voltage Storage Temperature Range .................. 65C to 150C (LTC1143, LTC1143L, Pins 2, 10)...........7V to 0.3V Lead Temperature (Soldering, 10 sec).................. 300C PACKAGE/ORDER INFORMATION TOP VIEW TOP VIEW ORDER PART ORDER PART + + NUMBER SENSE 1 1 16 SENSE 1 SENSE 3 1 16 SENSE 3 NUMBER 15 15 V 2 I SHUTDOWN 3 2 I FB1 TH1 TH3 GND1 3 14 C GND3 3 14 C T1 T3 LTC1143CS LTC1143LCS-ADJ P-DRIVE 1 4 13 V P-DRIVE 3 4 13 V IN3 IN1 LTC1143LCS V 5 12 P-DRIVE 2 V 5 12 P-DRIVE 5 IN2 IN5 C 6 11 C 6 11 GND2 GND5 T2 T5 I 7 10 V I 7 10 SHUTDOWN 5 TH2 TH5 FB2 + + SENSE 2 8 9 SENSE 2 SENSE 5 8 9 SENSE 5 S PACKAGE S PACKAGE 16-LEAD PLASTIC SO 16-LEAD PLASTIC SO T = 125C, = 95C/W T = 125C, = 95C/W JMAX JA JMAX JA Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS T = 25C, V = 10V unless otherwise noted. A IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V , V Feedback Voltage (LTC1143L-ADJ) V = 9V l 1.21 1.25 1.29 V 2 10 IN I , I Feedback Current (LTC1143L-ADJ) l 0.2 1 A 2 10 V Regulated Output Voltage (LTC1143/LTC1143L) V V = 9V, V = V = 0V OUT IN3, IN5 2 10 3.3V Output I = 700mA l 3.23 3.33 3.43 V LOAD = 700mA l 4.90 5.05 5.20 V 5V Output I LOAD V Output Voltage Line Regulation V = 7V to 12V, I = 50mA 40 0 40 mV OUT IN LOAD Output Voltage Load Regulation V = V = 0V 2 10 LTC1143/LTC1143L 3.3V Output 5mA < I < 2.0A l 40 65 mV LOAD 5V Output 5mA < I < 2.0A l 60 100 mV LOAD Output Ripple (Burst Mode) I = 0A 50 mV LOAD P-P I , I Input DC Supply Current (Note 2) 5 13 LTC1143: Normal Mode V = V = 0V, 4V < V < 12V 1.6 2.1 mA 2 10 IN Sleep Mode V = V = 0V, 4V < V < 12V, 6V < V < 12V 160 230 A 2 10 IN3 IN5 Shutdown V = V = 2.1V, 4V < V < 12V 10 20 A 2 10 IN LTC1143L: Normal Mode V = V = 0V, 3.5V < V < 12V 1.6 2.1 mA 2 10 IN Sleep Mode V = V = 0V, 3.5V < V < 12V, 6V < V < 12V 160 230 A 2 10 IN3 IN5 Shutdown V = V = 2.1V, 3.5V < V < 12V 10 20 A 2 10 IN LTC1143L-ADJ: Normal Mode 3.5V < V < 12V 1.6 2.1 mA IN Sleep Mode 3.5V < V < 12V, V 3.3V 160 230 A IN OUT 2 U W U U WWW