LTC3642 - High Efficiency, High Voltage 50mA Synchronous Step-Down Converter

Features

  • Wide Input Voltage Range: 4.5V to 45V
  • Tolerant of 60V Input Transients
  • Internal High Side and Low Side Power Switches
  • No Compensation Required
  • 50mA Output Current
  • Low Dropout Operation: 100% Duty Cycle
  • Low Quiescent Current: 12μA
  • 0.8V Feedback Voltage Reference
  • Adjustable Peak Current Limit
  • Internal and External Soft-Start
  • Precise RUN Pin Threshold with Adjustable Hysteresis
  • 3.3V, 5V and Adjustable Output Versions
  • Only Three External Components Required for Fixed Output Versions
  • Low Profile (0.75mm) 3mm × 3mm DFN and Thermally-Enhanced MS8E Packages
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC3642 Typical Application
LTC3642 Typical Application

Description

The LTC3642 is a high efficiency, high voltage step-down DC/DC converter with internal high side and synchronous power switches that draws only 12μA typical DC supply current at no load while maintaining output voltage regulation.

The LTC3642 can supply up to 50mA load current and features a programmable peak current limit that provides a simple method for optimizing efficiency in lower current applications. The LTC3642’s combination of Burst Mode® operation, integrated power switches, low quiescent current, and programmable peak current limit provides high efficiency over a broad range of load currents.

With its wide 4.5V to 45V input range and internal overvoltage monitor capable of protecting the part through 60V surges, the LTC3642 is a robust converter suited for regulating a wide variety of power sources. Additionally, the LTC3642 includes a precise run threshold and soft‑start feature to guarantee that the power system start-up is well-controlled in any environment.

The LTC3642 is available in the thermally enhanced 3mm × 3mm DFN and MS8E packages.

 

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
LTC3642EDD-3.3#PBF 3x3 DFN-8 DD E 05-08-1698 Yes
LTC3642EDD-3.3#TRPBF 3x3 DFN-8 DD E 05-08-1698 Yes
LTC3642EDD-5#PBF 3x3 DFN-8 DD E 05-08-1698 Yes
LTC3642EDD-5#TRPBF 3x3 DFN-8 DD E 05-08-1698 Yes
LTC3642EDD#PBF 3x3 DFN-8 DD E 05-08-1698 Yes
LTC3642EDD#TRPBF 3x3 DFN-8 DD E 05-08-1698 Yes
LTC3642EMS8E-3.3#PBF MS-8 MS8 E 05-08-1660 Yes
LTC3642EMS8E-3.3#TRPBF MS-8 MS8 E 05-08-1660 Yes
LTC3642EMS8E-5#PBF MS-8 MS8 E 05-08-1660 Yes
LTC3642EMS8E-5#TRPBF MS-8 MS8 E 05-08-1660 Yes
LTC3642EMS8E#PBF MS-8 MS8 E 05-08-1660 Yes
LTC3642EMS8E#TRPBF MS-8 MS8 E 05-08-1660 Yes
LTC3642IDD-3.3#PBF 3x3 DFN-8 DD I 05-08-1698 Yes
LTC3642IDD-3.3#TRPBF 3x3 DFN-8 DD I 05-08-1698 Yes
LTC3642IDD-5#PBF 3x3 DFN-8 DD I 05-08-1698 Yes
LTC3642IDD-5#TRPBF 3x3 DFN-8 DD I 05-08-1698 Yes
LTC3642IDD#PBF 3x3 DFN-8 DD I 05-08-1698 Yes
LTC3642IDD#TRPBF 3x3 DFN-8 DD I 05-08-1698 Yes
LTC3642IMS8E-3.3#PBF MS-8 MS8 I 05-08-1660 Yes
LTC3642IMS8E-3.3#TRPBF MS-8 MS8 I 05-08-1660 Yes
LTC3642IMS8E-5#PBF MS-8 MS8 I 05-08-1660 Yes
LTC3642IMS8E-5#TRPBF MS-8 MS8 I 05-08-1660 Yes
LTC3642IMS8E#PBF MS-8 MS8 I 05-08-1660 Yes
LTC3642IMS8E#TRPBF MS-8 MS8 I 05-08-1660 Yes


LTC3642 Package Drawing
LTC3642 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
LTC3642EDD-3.3#PBF 3x3 DFN-8 E $3.79 $2.65 Yes
LTC3642EDD-3.3#TRPBF 3x3 DFN-8 E $2.71 Yes
LTC3642EDD-5#PBF 3x3 DFN-8 E $3.79 $2.65 Yes
LTC3642EDD-5#TRPBF 3x3 DFN-8 E $2.71 Yes
LTC3642EDD#PBF 3x3 DFN-8 E $3.79 $2.65 Yes
LTC3642EDD#TRPBF 3x3 DFN-8 E $2.71 Yes
LTC3642EMS8E-3.3#PBF MS-8 E $3.79 $2.65 Yes
LTC3642EMS8E-3.3#TRPBF MS-8 E $2.71 Yes
LTC3642EMS8E-5#PBF MS-8 E $3.79 $2.65 Yes
LTC3642EMS8E-5#TRPBF MS-8 E $2.71 Yes
LTC3642EMS8E#PBF MS-8 E $3.79 $2.65 Yes
LTC3642EMS8E#TRPBF MS-8 E $2.71 Yes
LTC3642IDD-3.3#PBF 3x3 DFN-8 I $4.36 $3.05 Yes
LTC3642IDD-3.3#TRPBF 3x3 DFN-8 I $3.11 Yes
LTC3642IDD-5#PBF 3x3 DFN-8 I $4.36 $3.05 Yes
LTC3642IDD-5#TRPBF 3x3 DFN-8 I $3.11 Yes
LTC3642IDD#PBF 3x3 DFN-8 I $4.36 $3.05 Yes
LTC3642IDD#TRPBF 3x3 DFN-8 I $3.11 Yes
LTC3642IMS8E-3.3#PBF MS-8 I $4.36 $3.05 Yes
LTC3642IMS8E-3.3#TRPBF MS-8 I $3.11 Yes
LTC3642IMS8E-5#PBF MS-8 I $4.36 $3.05 Yes
LTC3642IMS8E-5#TRPBF MS-8 I $3.11 Yes
LTC3642IMS8E#PBF MS-8 I $4.36 $3.05 Yes
LTC3642IMS8E#TRPBF MS-8 I $3.11 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
DC1429A LTC3642EDD Demo Board | 60V Transients, 4.5V ≤ VIN ≤ 45V, Vout =1.8V/3.3V/5V/Adj @ 50mA $100.00
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
LTC3642IDD-3.3#PBF 3x3 DFN-8 I $4.36 $3.05 Yes
LTC3642IDD-3.3#TRPBF 3x3 DFN-8 I $3.11 Yes
LTC3642IDD-5#PBF 3x3 DFN-8 I $4.36 $3.05 Yes
LTC3642IDD-5#TRPBF 3x3 DFN-8 I $3.11 Yes
LTC3642IDD#PBF 3x3 DFN-8 I $4.36 $3.05 Yes
LTC3642IDD#TRPBF 3x3 DFN-8 I $3.11 Yes
LTC3642IMS8E-3.3#PBF MS-8 I $4.36 $3.05 Yes
LTC3642IMS8E-3.3#TRPBF MS-8 I $3.11 Yes
LTC3642IMS8E-5#PBF MS-8 I $4.36 $3.05 Yes
LTC3642IMS8E-5#TRPBF MS-8 I $3.11 Yes
LTC3642IMS8E#PBF MS-8 I $4.36 $3.05 Yes
LTC3642IMS8E#TRPBF MS-8 I $3.11 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

  • 4mA to 20mA Current Loops
  • Industrial Control Supplies
  • Distributed Power Systems
  • Portable Instruments
  • Battery-Operated Devices
  • Automotive Power Systems
 

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

Models for the following parts are available in LTspice:
LTC3642
LTC3642-3.3
LTC3642-5

Technical Support