LTC3672B-2 Datasheet | Linear Technology

Monolithic Fixed-Output 400m A Buck Regulator with Dual 150m A LDOs in 2mm × 2mm DFN Features n Triple Output Supply From a Single 2.9V to 5.5V Input n Buck DC/DC: Fixed 1.2V Output, Up to 400m A n LDO1: Fixed 2.8V Output, Up to 150m A n LDO2: Fixed 1.8V Output, Up to 150m A n ±2.5% Reference Accuracy n Constant-Frequency 2.25MHz Operation n Minimum External ponent Count n Current Mode Operation for Excellent Line and Load Transient Response n Internal Soft-Start for Each Output n Single Enable Pin Turns On/Shuts Down All Three Outputs n Tiny 2mm × 2mm × 0.75mm DFN Package APPLICATIONS n DMB and DVB-H Cellphones n Handheld Products (PDA, PMP, GPS) n Multivoltage Power for Digital Logic, I/O, FPGAs, CPLDs, ASICs, CPUs, and RF Chipsets DESCRIPTION The LTC®3672B-2 is a triple power supply posed of a 400m A synchronous buck regulator and two 150m A low-dropout linear regulators (LDOs). Constant-frequency 2.25MHz operation is maintained down to very light loads. The input supply range of 2.9V to 5.5V is especially wellsuited for single-cell Lithium-Ion and Lithium-Polymer applications, and for powering low voltage ASICs from 3.3V or 5V rails. The LTC3672B-2 regulates 1.2V at the buck output, 2.8V at the LDO1 output, and 1.8V at the LDO2 output. External ponent count is minimal- all that is needed is a single inductor, an input capacitor, and output capacitors for each of the three outputs. Control loop pensation is internal to the LTC3672B-2. The LTC3672B-2 is available in a 2mm × 2mm × 0.75mm 8-Lead DFN package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION 2.2μF VIN 2.9V TO 5.5V VIN VIN1 SW 4.7μH ENABLE INPUT GND BUCKOUT LTC3672B-2 LDO1 ENALL 4.7μF 1μF LDO2 3672B2 TA01 1μF VOUT1 1.2V 400m A VOUT2 2.8V, UP TO 150m A (SUBJECT TO DROPOUT LIMITATIONS) VOUT3 1.8V 150m A EFFICIENCY (%) Buck DC/DC Efficiency vs Buck...