POWER LOSS (mW) LTC3412A 3A, 4MHz, Monolithic Synchronous Step-Down Regulator FEATURES DESCRIPTION n High Efficiency: Up to 95% The LTC 3412A is a high efficiency monolithic synchro- n 3A Output Current nous, step-down DC/DC converter utilizing a constant n Low Quiescent Current: 64A frequency, current mode architecture. It operates from n Low R Internal Switch: 77m an input voltage range of 2.25V to 5.5V and provides a DS(ON) n 2.25V to 5.5V Input Voltage Range regulated output voltage from 0.8V to 5V while deliver- n Programmable Frequency: 300kHz to 4MHz ing up to 3A of output current. The internal synchronous n 2% Output Voltage Accuracy power switch with 77m on-resistance increases efficiency n 0.8V Reference Allows Low Output Voltage and eliminates the need for an external Schottky diode. n Selectable Forced Continuous/Burst Mode Operation Switching frequency is set by an external resistor or can with Adjustable Burst Clamp be synchronized to an external clock. 100% duty cycle n Synchronizable Switching Frequency provides low dropout operation extending battery life in n Low Dropout Operation: 100% Duty Cycle portable systems. OPTI-LOOP compensation allows the n Power Good Output Voltage Monitor transient response to be optimized over a wide range of n Overtemperature Protected loads and output capacitors. n Available in 16-Lead Exposed Pad TSSOP and The LTC3412A can be configured for either Burst Mode QFN Packages operation or forced continuous operation. Forced continu- ous operation reduces noise and RF interference while APPLICATIONS Burst Mode operation provides high efficiency by reducing n Point-of-Load Regulation gate charge losses at light loads. In Burst Mode operation, n Notebook Computers external control of the burst clamp level allows the output n Portable Instruments voltage ripple to be adjusted according to the application n Distributed Power Systems requirements. All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 6724174. TYPICAL APPLICATION 22F V Efficiency and Power Loss IN 3.3V 100 100000 PV SV IN IN EFFICIENCY 95 RT 2.2M PGOOD 90 10000 0.47H LTC3412A 294k V OUT 85 SW 2.5V AT 3A 80 1000 C OUT RUN/SS PGND 100F 75 12.1k 2 1000pF I SGND TH 70 100 SYNC/MODE V FB 65 POWER LOSS 820pF 60 10 69.8k 392k 55 115k 3412A F01a 50 1 0.01 0.1 1 10 LOAD CURRENT (A) 3412A F01b Figure1. 2.5V/3A Step-Down Regulator Rev. G 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTC3412A ABSOLUTE MAXIMUM RATINGS (Note 1) Input Supply Voltage .................................... 0.3V to 6V Operating Junction Temperature Range (Notes 2, 5) I , RUN/SS, V , PGOOD, E-, I-Grades .......................................40C to 125C TH FB SYNC/MODE Voltages ....................................0.3 to V MP-Grade ..........................................55C to 125C IN SW Voltages ..................................0.3V to (V + 0.3V) Storage Temperature Range ....................65C to150C IN Lead Temperature (Soldering, 10 sec) .................. 300C PIN CONFIGURATION TOP VIEW TOP VIEW SV 1 16 PV IN IN PGOOD 2 15 SW 16 15 14 13 I 3 14 SW TH RUN/SS 1 12 PGOOD V 4 13 PGND FB 17 SGND 2 11 SV IN R 5 12 PGND T 17 PV 3 10 PV IN IN SYNC/MODE 6 11 SW SW SW 4 9 RUN/SS 7 10 SW 5 6 7 8 SGND 8 9 PV IN FE PACKAGE 16-LEAD PLASTIC TSSOP UF PACKAGE T = 125C, = 38C/W, = 10C/W 16-LEAD (4mm 4mm) PLASTIC QFN JMAX JA JC EXPOSED PAD (PIN 17) IS SGND, MUST BE SOLDERED TO PCB T = 125C, = 37C/W, = 5C/W JMAX JA JC EXPOSED PAD (PIN 17) IS GND, MUST BE CONNECTED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3412AEFE PBF LTC3412AEFE TRPBF 3412AEFE 16-Lead Plastic TSSOP 40C to 125C LTC3412AIFE PBF LTC3412AIFE TRPBF 3412AIFE 16-Lead Plastic TSSOP 40C to 125C LTC3412AMPFE PBF LTC3412AMPFE TRPBF 3412AMPFE 16-Lead Plastic TSSOP 55C to 125C LTC3412AEUF PBF LTC3412AEUF TRPBF 3412A 16-Lead (4mm 4mm) Plastic QFN 40C to 125C LTC3412AIUF PBF LTC3412AIUF TRPBF 3412A 16-Lead (4mm 4mm) Plastic QFN 40C to 125C LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3412AEFE LTC3412AEFE TR 3412AEFE 16-Lead Plastic TSSOP 40C to 125C LTC3412AIFE LTC3412AIFE TR 3412AIFE 16-Lead Plastic TSSOP 40C to 125C LTC3412AMPFE LTC3412AMPFE TR 3412AMPFE 16-Lead Plastic TSSOP 55C to 125C LTC3412AEUF LTC3412AEUF TR 3412A 16-Lead (4mm 4mm) Plastic QFN 40C to 125C LTC3412AIUF LTC3412AIUF TR 3412A 16-Lead (4mm 4mm) Plastic QFN 40C to 125C Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with TRMPBF suffix. Rev. G 2 For more information www.analog.com SW SYNC/MODE PGND R T PGND V FB SW I TH