Datasheet LTC3601 (Analog Devices)

LTC3601 1.5A, 15V Monolithic Synchronous Step-Down Regulator
FEATURES DESCRIPTION
n
4V to 15V Operating Input Voltage Range
The LTC®3601 is a high efficiency, monolithic synchronous n
1.5A Output Current
buck regulator using a phase-lockable controlled on-time, n
Up to 96% Efficiency
current mode architecture capable of supplying up to 1.5A n
Very Low Duty Cycle Operation: 5% at 2.25MHz
of output current. The operating supply voltage range is n
Adjustable Switching Frequency: 800kHz to 4MHz
from 4V to 15V, making it suitable for a wide range of n
External Frequency Synchronization
power supply applications. n
Current Mode Operation for Excellent Line and Load
The operating frequency is programmable from 800kHz to
Transient Response
4MHz with an external resistor enabling the use of small n User Selectable Burst Mode® (No Load IQ = 300µA) or surface mount inductors. For switching noise sensitive Forced Continuous Operation applications, the LTC3601 can be externally synchronized n 0.6V Reference Allows Low Output Voltages over the same frequency range. An internal phase-locked n Short-Circuit Protected loop aligns the on-time of the top power MOSFET to the n Output Voltage Tracking Capability internal or external clock. This unique constant frequency/ n Programmable Soft-Start controlled on-time architecture is ideal for high step-down n Power Good Status Output ratio applications that demand high switching frequencies n Available in Small, Thermally Enhanced 16-Pin QFN and fast transient response. (3mm × 3mm) and MSOP Packages The LTC3601 offers two operational modes: Burst Mode
APPLICATIONS
operation and forced continuous mode to allow the user to optimize output voltage ripple, noise, and light load n Distributed Power Systems efficiency for a given application. Maximum light load n Lithium-Ion Battery-Powered Instruments efficiency is achieved with the selection of Burst Mode n Point-of-Load Power Supply operation while forced continuous mode provides minimum L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks and Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the output ripple and constant frequency operation. property of their respective owners. Protected by U.S. Patents, including 5481178, 5847554, 6580258, 6304066, 6476589, 6774611.
TYPICAL APPLICATION Efficiency and Power Loss vs Load Current
100 1000 90 VIN 80 VIN BOOST 4V TO 15V RUN POWER LOSS (mW) 22µF 0.1µF 70 2.2µH V 100 OUT PGOOD SW 3.3V 60 TRACK VON 1.5A 180k 10pF 22µF 50 LTC3601 40 INTVCC FB EFFICIENCY (%) 10 2.2µF ITH 30 RT 40k MODE/SYNC 20 3601 TA01a SGND PGND 10 VIN = 5V VIN = 12V 0 1 0.001 0.01 0.1 1 10 LOAD CURRENT (A) 3601 TA01b 3601fc For more information www.linear.com/LTC3601 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Related Parts