Datasheet LTC3604 (Analog Devices)

LTC3604 2.5A, 15V Monolithic Synchronous Step-Down Regulator
FEATURES DESCRIPTION
n
3.6V to 15V Operating Input Voltage Range
The LTC®3604 is a high efficiency, monolithic synchronous n
2.5A Output Current
buck regulator using a phase-lockable controlled on-time, n
Up to 95% Efficiency
current mode architecture capable of supplying up to 2.5A 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 3.6V 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 Low Ripple (20mVP-P Typical) surface mount inductors. For switching noise sensitive Burst Mode® (No Load IQ = 300µA) or Forced applications, the LTC3604 can be externally synchronized Continuous Operation over the same frequency range. An internal phase-locked n 0.6V Reference Allows Low Output Voltages loop aligns the on-time of the top power MOSFET to the n Short-Circuit Protected internal or external clock. This unique constant frequency/ n Output Voltage Tracking Capability 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 LTC3604 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 Supplies 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 registered trademark of Linear Technology Corporation. All other trademarks output ripple and constant frequency operation. are the 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 10
High Efficiency 2.5A Step-Down Regulator
90 VIN V 80 IN BOOST 3.6V TO 15V 1 RUN 0.1µF POWER LOSS (W) 22µF 70 1µH VOUT PGOOD SW 3.3V 60 TRACK/SS VON 2.5A 50 0.1 180k 22pF 47µF LTC3604 40 INTVCC FB EFFICIENCY (%) 30 2.2µF ITH V 0.01 RT 40k IN = 5V 20 MODE/SYNC VIN = 12V 3604 TA01a SGND PGND 10 fO = 2MHz Burst Mode OPERATION 0 0.001 0.001 0.01 0.1 1 10 LOAD CURRENT (A) 3604 TA01b 3604fa For more information www.linear.com/LTC3604 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Operation Applications Information Typical Applications Package Description Revision History Related Parts