POWER LOSS (W) LTM4691 Low V , High Efficiency, Dual 2A IN Step-Down DC/DC Module Regulator FEATURES DESCRIPTION n Tiny Surface Mount, Low Profile 3mm 4mm The LTM 4691 is a complete dual 2A output switch- 1.18mm LGA Package and 3mm 4mm 1.48mm ing mode DC/DC power supply in a tiny 3mm 4mm BGA Package 1.18mm LGA package and a 3mm 4mm 1.48mm n Input Voltage Range: 2.25V to 3.6V BGA package. Included in the package are the switch- n Dual 2A DC Output Current ing controller, power FETs, inductors and all supporting n 1.5% Total Output Voltage Regulation components. Operating over an input voltage range of n Current Mode Control, Fast Transient Response 2.25V to 3.6V, the LTM4691 supports two outputs with n External Frequency Synchronization programmable output voltage range from 0.5V to 2.5V set n 180 Out-of-Phase Operation by external resistors. Its high efficiency design delivers up n Selectable Pulse-Skipping Mode/Burst Mode to 2A continuous current on each output. Only bulk input Operation/Forced Continuous Mode and output capacitors are needed. n Power Good Indicator The LTM4691 operates in forced continuous mode for low n Internal Soft-Start noise pulse-skipping mode or Burst Mode operation for n Internal Compensation high efficiency at lights loads. The typical buck switching n Overvoltage, Overcurrent and Overtemperature frequency is 2MHz and can be synchronized from 1MHz to Protection 3MHz. Its high switching frequency and a current mode architecture enables a very fast transient response to line APPLICATIONS and load changes without sacrificingstability. n Telecom, Networking and Industrial Equipment Other features include precision run thresholds, a PGOOD n Point-of-Load Regulation signal, output overvoltage protection, thermal shutdown n FPGA, ASIC Core Supplies and output short-circuit protection. The LTM4691 is Pb-free and RoHS compliant. All registered trademarks and trademarks are the property of their respective owners. TYPICAL APPLICATION Dual 2A DC/DC Module Regulator Efficiency vs Load Current 0.6 100 V V IN OUT1 V V EFFICIENCY IN OUT1 2.25V TO 3.6V 1.2V, 2A 90 10F 0.5 140k 2.7pF 80 22F FB1 70 0.4 RUN1 Burst Mode OPERATION 100k 60 V = 3.3V, V = 1.8V LTM4691 IN OUT V f = 2MHz IN SW 50 0.3 CH1 OFF V OUT2 10F V OUT2 1.8V, 2A 40 0.2 261k 1.2pF RUN2 30 22F MODE/SYNC FB2 20 0.1 100k PGOOD 10 GND POWER LOSS 4691 TA01a f = 2MHz 0 0 SW 0.001 0.01 0.1 1 10 LOAD CURRENT (A) 4691 TA01b Rev. A 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTM4691 TABLE OF CONTENTS Features ............................................................................................................................ 1 Applications ....................................................................................................................... 1 Typical Application ............................................................................................................... 1 Description......................................................................................................................... 1 Absolute Maximum Ratings ..................................................................................................... 3 Order Information ................................................................................................................. 3 Pin Configuration ................................................................................................................. 3 Electrical Characteristics ........................................................................................................ 4 Typical Performance Characteristics .......................................................................................... 6 Pin Functions ...................................................................................................................... 8 Block Diagram ..................................................................................................................... 9 Decoupling Requirements ....................................................................................................... 9 Operation..........................................................................................................................10 Applications Information .......................................................................................................11 V to V Step-Down Ratios .............................................................................................................................. 11 IN OUT Output Voltage Programming ............................................................................................................................... 11 Input Decoupling Capacitors ................................................................................................................................. 11 Output Decoupling Capacitors .............................................................................................................................. 11 Mode Selection .................................................................................................................................................... 11 Operating Frequency and External Synchronization ............................................................................................. 12 Power GOOD ........................................................................................................................................................ 12 Output Overvoltage Protection .............................................................................................................................. 12 Output Voltage Soft-Start ...................................................................................................................................... 13 Dropout Operation ............................................................................................................................................... 13 Output Short-Circuit Protection and Recovery ...................................................................................................... 13 Load Sharing ........................................................................................................................................................ 13 Using the Precision RUN Threshold ..................................................................................................................... 13 Thermal Considerations and Output Current Derating .......................................................................................... 14 Safety Considerations ........................................................................................................................................... 17 Layout Checklist/Example ..................................................................................................................................... 17 Applications Information .......................................................................................................18 Typical Applications .............................................................................................................19 Pin Configuration Table .........................................................................................................20 LTM4691 Component LGA and BGA Pinout ......................................................................................................... 20 Package Description ............................................................................................................21 Revision History .................................................................................................................23 Package Photo ...................................................................................................................24 Related Parts .....................................................................................................................24 Rev. A 2 For more information www.analog.com