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. 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. 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 Figure 1. 2.5V/3A Step-Down Regulator 3412aff 1 FFoorr mmoorree iinnffoorrmmaattiioonn wwwwww..lliinneeaarr..ccoomm//LLTTCC33414122AA 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