LTC3412 2.5A, 4MHz, Monolithic Synchronous Step-Down Regulator FEATURES DESCRIPTION The LTC 3412 is a high efficiency monolithic synchro- High Efficiency: Up to 95% nous, step-down DC/DC converter utilizing a constant 2.5A Output Current frequency, current mode architecture. It operates from Low Quiescent Current: 62A an input voltage range of 2.625V to 5.5V and provides Low R Internal Switches: 85m DS(ON) an adjustable regulated output voltage from 0.8V to 5V Programmable Frequency: 300kHz to 4MHz while delivering up to 2.5A of output current. The inter- No Schottky Diode Required nal synchronous power switch with 85m on-resistance 2% Output Voltage Accuracy increases efficiency and eliminates the need for an external 0.8V Reference Allows Low Output Voltage Schottky diode. Switching frequency is set by an external Selectable Forced Continuous/Burst Mode Operation resistor or can be sychronized to an external clock. 100% with Adjustable Burst Clamp duty cycle provides low dropout operation extending bat- Synchronizable Switching Frequency tery life in portable systems. OPTI-LOOP compensation Low Dropout Operation: 100% Duty Cycle allows the transient response to be optimized over a wide Power Good Output Voltage Monitor range of loads and output capacitors. Overtemperature Protection Available in 16-Lead Thermally Enhanced TSSOP The LTC3412 can be configured for either Burst Mode and QFN Packages operation or forced continuous operation. Forced con- tinuous operation reduces noise and RF interference while Burst Mode operation provides high efficiency by APPLICATIONS reducing gate charge losses at light loads. In Burst Mode Portable Instruments operation, external control of the burst clamp level allows Battery-Powered Equipment the output voltage ripple to be adjusted according to the Notebook Computers requirements of the application. To further maximize bat- Distributed Power Systems tery life, the P-channel MOSFET is turned on continuously Cellular Telephones in dropout (100% duty cycle). Digital Cameras L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Analog Devices, Inc. All other trademarks are the property of their respective owners. TYPICAL APPLICATION Efficiency vs Load Current V IN 100 2.7V TO 5.5V 22F SV PV IN IN R 80 PGOOD T 1H V OUT Burst Mode OPERATION 309k 4.7M SW 2.5V 2.5A LTC3412 100F 60 PGND RUN/SS FORCED CONTINUOUS 470pF SGND 15k 40 I TH SYNC/MODE V FB 1000pF 100pF 20 110k 392k V = 3.3V 3412 F01 IN V = 2.5V OUT 75k 0 0.001 0.01 0.1 1 10 LOAD CURRENT (A) 3412 G01 Figure 1. 2.5V, 2.5A Step-Down Regulator 3412fc 1 For more information www.linear.com/LTC3412 EFFICIENCY (%)LTC3412 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Supply Voltage ....................................0.3V to 6V Operating Temperature Range (Note 2)....40C to 85C I , RUN, V Voltages ............................... 0.3V to V Storage Temperature Range .................. 65C to 150C TH FB IN SYNC/MODE Voltages ................................. 0.3V to V Junction Temperature (Note 5) ............................. 125C IN SW Voltage ................................... 0.3V to (V + 0.3V) Lead Temperature (Soldering, 10 sec) TSSOP ......300C IN Peak SW Sink and Source Current ..........................6.5A PIN CONFIGURATION TOP VIEW TOP VIEW SV 1 16 PV IN IN PGOOD 2 15 SW I 3 14 SW TH 16 15 14 13 V 4 13 PGND RUN/SS 1 12 PGOOD FB 17 R 5 12 PGND SGND 2 11 SV T IN 17 PV PV SYNC/MODE 6 11 SW 3 10 IN IN SW 4 9 SW RUN/SS 7 10 SW 5 6 7 8 SGND 8 9 PV IN FE PACKAGE 16-LEAD PLASTIC TSSOP UF PACKAGE EXPOSED PAD (PIN 17) IS SGND, MUST BE SOLDERED TO PCB 16-LEAD (4mm 4mm) PLASTIC QFN T = 125C, = 37.6C/W, = 10C/W JMAX JA JC EXPOSED PAD (PIN 17) IS SGND, MUST BE SOLDERED TO PCB T = 125C, = 34C/W, = 1C/W JMAX JA JC ORDER INFORMATION