LTC3548 - Dual Synchronous, 400mA/800mA, 2.25MHz Step-Down DC/DC Regulator

Features

  • High Efficiency: Up to 95%
  • Very Low Quiescent Current: Only 40μA
  • Low Output Ripple Burst Mode® Operation
  • 2.25MHz Constant Frequency Operation
  • High Switch Current: 0.7A and 1.2A
  • No Schottky Diodes Required
  • Low RDS(ON) Internal Switches: 0.35Ω
  • Current Mode Operation for Excellent Line and Load Transient Response
  • Short-Circuit Protected
  • Low Dropout Operation: 100% Duty Cycle
  • Ultralow Shutdown Current: IQ < 1μA
  • Output Voltages from 5V down to 0.6V
  • Power-On Reset Output
  • Externally Synchronizable Oscillator
  • Small Thermally Enhanced MSOP and 3mm × 3mm DFN Packages
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC3548 Typical Application
LTC3548 Typical Application

Description

The LTC®3548 is a dual, constant frequency, synchronous step down DC/DC converter. Intended for low power applications, it operates from 2.5V to 5.5V input voltage range and has a constant 2.25MHz switching frequency, allowing the use of tiny, low cost capacitors and inductors with a profile ≤1mm. Each output voltage is adjustable from 0.6V to 5V. Internal synchronous 0.35Ω, 0.7A/1.2A power switches provide high efficiency without the need for external Schottky diodes.

A user selectable mode input is provided to allow the user to trade-off noise ripple for low power efficiency. Burst Mode operation provides high efficiency at light loads, while Pulse-Skipping Mode provides low noise ripple at light loads.

To further maximize battery runtime, the P-channel MOSFETs are turned on continuously in dropout (100% duty cycle), and both channels draw a total quiescent current of only 40μA. In shutdown, the device draws <1μA.

  Features 
LTC3548A Improved Burst Mode, Improved ESD, 2 Adjustable Outputs
LTC3548-2 One Fixed 1.8V Output, 1 Adjustable
LTC3548-1 Fixed 1.8V and 1.575V Outputs
LTC3548 2 Adjustable Outputs

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
LTC3548EDD#PBF 3x3 DFN-10 DD E 05-08-1699 Yes
LTC3548EDD#TRPBF 3x3 DFN-10 DD E 05-08-1699 Yes
LTC3548EMSE#PBF MS-10E MSE E 05-08-1664 Yes
LTC3548EMSE#TRPBF MS-10E MSE E 05-08-1664 Yes
LTC3548IDD#PBF 3x3 DFN-10 DD I 05-08-1699 Yes
LTC3548IDD#TRPBF 3x3 DFN-10 DD I 05-08-1699 Yes
LTC3548IMSE#PBF MS-10E MSE I 05-08-1664 Yes
LTC3548IMSE#TRPBF MS-10E MSE I 05-08-1664 Yes


LTC3548 Package Drawing
LTC3548 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
LTC3548EDD#PBF 3x3 DFN-10 E $3.71 $2.60 Yes
LTC3548EDD#TRPBF 3x3 DFN-10 E $2.66 Yes
LTC3548EMSE#PBF MS-10E E $3.71 $2.60 Yes
LTC3548EMSE#TRPBF MS-10E E $2.66 Yes
LTC3548IDD#PBF 3x3 DFN-10 I $4.27 $2.99 Yes
LTC3548IDD#TRPBF 3x3 DFN-10 I $3.05 Yes
LTC3548IMSE#PBF MS-10E I $4.27 $2.99 Yes
LTC3548IMSE#TRPBF MS-10E I $3.05 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
DC822A LTC3548EDD Demo Board | 2.5V ≤ VIN ≤ 5.5V, Vout1 = 1.2V1.5V/1.8V @ 800mA, Vout2 = 2.5V @ 400mA Contact Factory
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC3548IDD#PBF 3x3 DFN-10 I $4.27 $2.99 Yes
LTC3548IDD#TRPBF 3x3 DFN-10 I $3.05 Yes
LTC3548IMSE#PBF MS-10E I $4.27 $2.99 Yes
LTC3548IMSE#TRPBF MS-10E I $3.05 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.

Applications

  • PDAs/Palmtop PCs
  • Digital Cameras
  • Cellular Phones
  • Portable Media Players
  • PC Cards
  • Wireless and DSL Modems

Product Notifications

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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

To launch a ready to run LTspice demonstration circuit for this part:

  • Step 1: If you have not installed LTspice on this computer, download and install LTspice
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice:
LTC3548
LTC3548-1
LTC3548A

Technical Support