LTC3544 - Quad Synchronous Step-Down Regulator: 2.25MHz, 300mA, 200mA, 200mA, 100mA

The LTC3544 is a quad, high efficiency, monolithic synchronous buck regulator using a constant-frequency, current mode architecture. The four regulators operate independently with separate run pins. The 2.25V to 5.5V input voltage range makes the LTC3544 well suited for single Li-Ion/polymer battery-powered applications. 100% duty cycle provides low dropout operation, extending battery runtime in portable systems. Low ripple Burst Mode® operation increases efficiency at light loads, further extending battery runtime with typically only 20mV of ripple.

Switching frequency is internally set to 2.25MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switches increase efficiency and eliminate the need for external Schottky diodes. Low output voltages are easily supported with the 0.8V feedback reference voltage.

The LTC3544 is available in a low profile (0.75mm) (3mm × 3mm) QFN package.

Features
  • High Efficiency: Up to 95%
  • Four Independent Regulators Provide Up to 300mA, 200mA, 200mA and 100mA Output Current
  • 2.25V to 5.5V Input Voltage Range
  • 2.25MHz Constant-Frequency Operation
  • No Schottky Diodes Required
  • Extremely Low Channel-to-Channel Transient Crosstalk
  • Low Ripple (20mVP-P) Burst Mode Operation: IQ = 70µA (All Channels On)
  • 0.8V Reference Allows Low Output Voltages
  • Shutdown Mode Draws <1µA Supply Current
  • Current Mode Operation for Excellent Line and Load Transient Response
  • Overtemperature Protected
  • Low Profile (3mm × 3mm) 16-Lead QFN Package
Typical Application

Applications
  • Cellular Telephones
  • Personal Information Appliances
  • Wireless and DSL Modems
  • Digital Still Cameras
  • Media Players
  • Portable Instruments
Packaging
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC3544EUD#PBF3x3 QFN-16E$4.21$2.95
LTC3544EUD#TRPBF3x3 QFN-16E$3.01
Demo Boards
Part NumberDescriptionPrice
DC1040A-ALTC3544EUD Demo Board | Quad Sync Buck, 2.25V ≤ VIN ≤ 5.5V, Iout = 100mA, 200mA(x2) & 300mAContact Factory
Datasheet
Reliability Data
LTspice
Related Product
LTC3544 - Quad Synchronous Step-Down Regulator: 2.25MHz, 300mA, 200mA, 200mA, 100mA
R415 - Reliability Data
LTC3544 Footprints and Symbols
LTC3544 Demo Circuit - Quad Synchronous 2.25MHz Step-Down Regulator (5V to 1.2V @ 100mA, 1.8V @ 300mA, 0.8V @ 200mA & 1.5V@200mA)