LTC3670 Datasheet | Linear Technology

Monolithic 400m A Buck Regulator with Dual 150m A LDOs in 3mm × 2mm DFN Features DESCRIPTION n Triple Output Supply from a Single 2.5V to 5.5V Input n 400m A Buck DC/DC Plus Dual 150m A LDOs in One IC n Outputs Regulate Down to 0.8V n ±2.5% Reference Accuracy n Constant-Frequency 2.25MHz Operation n Burst Mode® Operation for High Efficiency at Light Loads; IQ = 70µA, All Outputs Enabled n Independent Enable Pin for Each Output n Current Mode Operation for Excellent Line and Load Transient Response n Internal Soft-Start for Each Output n Tiny 12-Lead 3mm × 2mm × 0.75mm DFN Package APPLICATIONS n Handheld Products n Portable Instruments n Single-Cell Li-Ion/Li-Polymer Powered Devices n DMB/DVB-H Multimedia Cell Phones n Multivoltage Power for Digital Logic, I/O, FPGAs, CPLDs, ASICs, So Cs, CPUs and RF Chipsets The LTC®3670 is a triple power supply posed of a 400m A synchronous buck regulator and two 150m A low dropout linear regulators (LDOs). The input supply range of 2.5V to 5.5V is especially well-suited for single-cell Lithium-Ion and Lithium-Ion/Polymer applications, and for powering low voltage ASICs and So Cs from 3V, 3.3V or 5V rails. Regulated output voltages are programmed via external resistors. Each output has its own enable pin for maximum flexibility. The 400m A buck regulator Features constant-frequency 2.25MHz operation, allowing small surface mount inductors and capacitors to be used. Burst Mode operation maintains high efficiency in light-load and no-load conditions. Internal control-loop pensation simplifies application design. The LTC3670 is available in a 0.75mm profile, 3mm × 2mm 12-lead DFN package. All registered trademarks and trademarks are the property of their respective owners. TYPICAL APPLICATION Triple Power Supply with Independent Enables VIN 3.3V TO 5.5V 2.2µF DIGITAL CONTROL VIN GND BUCKFB ENBUCK ENLDO1 ENLDO2 PGOOD LDO1 LDO1_FB 4.7µH 232k 464k 806k 324k 10p F LDO2 LDO2_FB 1.02M 324k...