LTC3543 - 600mA Synchronous Step Down Buck Regulator with PLL, Soft-Start and Spread Spectrum

Features

  • 600mA Output Current
  • 2.5V to 5.5V Input Voltage Range
  • 2.25MHz Constant Frequency Operation, Spread Spectrum or Synchronized PLL (1MHz to 3MHz)
  • High Efficiency: Up to 95%
  • 1A Peak Inductor Current
  • Very Low Quiescent Current: Only 45µA During Burst Mode Operation
  • No Schottky Diode Required
  • Low Dropout Operation: 100% Duty Cycle
  • Overtemperature Protected
  • Stable with Ceramic Capacitors
  • Shutdown Mode Draws <1µA Supply Current
  • ±2% Output Voltage Accuracy
  • Current Mode Operation for Excellent Line and Load Transient Response
  • Soft-Start
  • Available in a Low Profi le (0.75mm) 2mm × 3mm 6-Lead DFN Package

Typical Application

LTC3543 Typical Application
LTC3543 Typical Application

Description

The LTC3543 is a high efficiency monolithic synchronous current mode buck regulator.

The switching frequency is internally set at 2.25MHz, allowing the use of small surface mount inductors and capacitors. In PLL mode, the LTC3543 can acquire frequencies between 1MHz and 3MHz. Also, the LTC3543 has spread spectrum capability providing a lower noise regulated output, as well as low noise at the input.

In Burst Mode® 0peration, the supply current is only 45µA, dropping to <1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3543 ideally suited for single Li-Ion battery-powered applications. The 100% duty cycle provides a low dropout operation, extending the battery life in portable systems. Burst Mode operation increases efficiency at light loads, further extending battery life. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC3543EDCB#PBF 2x3 DFN-6 DCB E 05-08-1715 Yes
LTC3543EDCB#TRMPBF 2x3 DFN-6 DCB E 05-08-1715 Yes
LTC3543EDCB#TRPBF 2x3 DFN-6 DCB E 05-08-1715 Yes


LTC3543 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC3543EDCB#PBF 2x3 DFN-6 E $2.79 Yes
LTC3543EDCB#TRMPBF 2x3 DFN-6 E $2.79 $2.00 Yes
LTC3543EDCB#TRPBF 2x3 DFN-6 E $2.79 $1.95 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1008A LTC3543EDC8 Demo Board | 2.5V ≤ VIN ≤ 5.5V, VOUT = 1.8V @ 600mA Contact Factory
Buy Now
Click here to view our complete list of demo boards

Applications

  • Portable Instruments
  • Cellular Phones

Product Notifications

Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.

Forgot your password? Click here.
Need help? Email mylinear@linear.com with questions and comments.

Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

Models for the following parts are available in LTspice:
LTC3543

Technical Support