LTC3670 Monolithic 400mA Buck Regulator with Dual 150mA LDOs in 3mm 2mm DFN FEATURES DESCRIPTION n Triple Output Supply from a Single 2.5V to 5.5V Input The LTC 3670 is a triple power supply composed of a n 400mA Buck DC/DC Plus Dual 150mA LDOs in One IC 400mA synchronous buck regulator and two 150mA low n Outputs Regulate Down to 0.8V dropout linear regulators (LDOs). The input supply range n 2.5% Reference Accuracy of 2.5V to 5.5V is especially well-suited for single-cell n Constant-Frequency 2.25MHz Operation Lithium-Ion and Lithium-Ion/Polymer applications, and n Burst Mode Operation for High Ef ciency at Light for powering low voltage ASICs and SoCs from 3V, 3.3V Loads I = 70A, All Outputs Enabled or 5V rails. Regulated output voltages are programmed Q n Independent Enable Pin for Each Output via external resistors. Each output has its own enable pin n Current Mode Operation for Excellent Line and Load for maximum exibility. Transient Response The 400mA buck regulator features constant-frequency n Internal Soft-Start for Each Output 2.25MHz operation, allowing small surface mount induc- n Tiny 12-Lead 3mm 2mm 0.75mm DFN Package tors and capacitors to be used. Burst Mode operation maintains high ef ciency in light-load and no-load con- APPLICATIONS ditions. Internal control-loop compensation simpli es n Handheld Products application design. n Portable Instruments The LTC3670 is available in a 0.75mm pro le, 3mm n Single-Cell Li-Ion/Li-Polymer Powered Devices 2mm 12-lead DFN package. n DMB/DVB-H Multimedia Cell Phones L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. n Multivoltage Power for Digital Logic, I/O, FPGAs, All other trademarks are the property of their respective owners. Patents pending. CPLDs, ASICs, SoCs, CPUs and RF Chipsets TYPICAL APPLICATION Triple Power Supply with Independent Enables Demoboard V IN 3.3V TO 5.5V 2.2F V IN 4.7H V OUT1 1.2V GND SW 400mA 232k 10pF 4.7F BUCKFB 464k 9.3mm LTC3670 V OUT2 ENBUCK LDO1 2.8V DIGITAL ENLDO1 150mA 9.4mm 806k 1F CONTROL ENLDO2 ACTIVE AREA LDO1 FB PGOOD 324k V OUT3 LDO2 3.3V 3670 TA01b 150mA 1.02M 1F LDO2 FB 324k 3670 TA01a 3670f 1LTC3670 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Notes 1, 2, 3) TOP VIEW V , ENBUCK, ENLDO1, ENLDO2, IN PGOOD .................................................... 0.3V to 6V SW 1 12 V IN SW, BUCKFB, LDO1 FB, LDO2 FB, GND 2 11 LDO2 ENLD01 3 LDO1 10 LDO1, LDO2 ...............................0.3V to (V + 0.3V) IN 13 ENLD02 4 9 LDO1 FB I .......................................................................600mA SW ENBUCK 5 8 LDO2 FB I , I ..........................................................250mA LDO1 LDO2 BUCKFB 7 PGOOD 6 I ....................................................................40mA PGOOD DDB PACKAGE Junction Temperature ........................................... 125C 12-LEAD (3mm 2mm) PLASTIC DFN T = 125C, = 76C/W, = 13.5C/W Operating Temperature Range.................. 40C to 85C JMAX JA JC EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB Storage Temperature Range ................... 65C to 125C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3670EDDB PBF LTC3670EDDB TRPBF LDBY 40C to 85C 12-Lead (3mm 2mm) Plastic DFN Consult LTC Marketing for parts speci ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: