LTC3833 - Fast Accurate Step-Down DC/DC Controller with Differential Output Sensing

Features

  • Wide VIN Range: 4.5V to 38V
  • VOUT Range: 0.6V to 5.5V
  • Output Accuracy: ±0.25% at 25°C and ±0.67% over Temperature
  • Differential Output Sensing Allowing Up to 500mV Line Loss
  • Fast Load Transient Response
  • tON(MIN) = 20ns, tOFF(MIN) = 90ns
  • Controlled On-Time Valley Current Mode Architecture
  • Frequency Programmable from 200kHz to 2MHz and Synchronizable to External Clock
  • RSENSE or Inductor DCR Current Sensing
  • Overvoltage Protection and Current Limit Foldback
  • Power Good Output Voltage Monitor
  • Output Tracking or Adjustable Soft-Start
  • External VCC Input for Bypassing Internal LDO
  • 20-Pin QFN (3mm × 4mm) and TSSOP Packages
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC3833 Typical Application
LTC3833 Typical Application

Description

The LTC3833 is a synchronous step-down DC/DC switching regulator controller targeted for high power applications. It drives all N-channel power MOSFETs. The controlled on-time valley current mode architecture allows for both fast transient response and constant frequency switching in steady-state operation, independent of VIN, VOUT and load current.

Differential output voltage sensing along with a precision internal reference combine to offer ±0.67% output regulation and the ability to correct for up to ±500mV variations in the output terminals due to line losses. The operating frequency can be programmed from 200kHz to 2MHz with an external resistor and can be synchronized to an external clock for noise and EMI sensitive applications.

Very low tON and tOFF times allow for near 0% and near 100% duty cycles, respectively. Programmable soft-start or output voltage tracking is available. Safety features include output overvoltage protection, programmable current limit with foldback, and a power good output signal.

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
LTC3833EFE#PBF TSSOP-20 FE E 05-08-1663 (CB) Yes
LTC3833EFE#TRPBF TSSOP-20 FE E 05-08-1663 (CB) Yes
LTC3833EUDC#PBF 3x4 QFN-20 UDC E 05-08-1742 Yes
LTC3833EUDC#TRPBF 3x4 QFN-20 UDC E 05-08-1742 Yes
LTC3833IFE#PBF TSSOP-20 FE I 05-08-1663 (CB) Yes
LTC3833IFE#TRPBF TSSOP-20 FE I 05-08-1663 (CB) Yes
LTC3833IUDC#PBF 3x4 QFN-20 UDC I 05-08-1742 Yes
LTC3833IUDC#TRPBF 3x4 QFN-20 UDC I 05-08-1742 Yes


LTC3833 Package Drawing
LTC3833 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
LTC3833EFE#PBF TSSOP-20 E $3.79 $2.65 Yes
LTC3833EFE#TRPBF TSSOP-20 E $2.71 Yes
LTC3833EUDC#PBF 3x4 QFN-20 E $3.57 $2.50 Yes
LTC3833EUDC#TRPBF 3x4 QFN-20 E $2.56 Yes
LTC3833IFE#PBF TSSOP-20 I $4.36 $3.05 Yes
LTC3833IFE#TRPBF TSSOP-20 I $3.11 Yes
LTC3833IUDC#PBF 3x4 QFN-20 I $4.14 $2.90 Yes
LTC3833IUDC#TRPBF 3x4 QFN-20 I $2.96 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
DC1516A-A LTC3833EFE Demo Board | VIN = 4.5V to 24V, VOUT1 = 1.5V @ 15A, Inductor DCR Sensing $125.00
DC1516A-B LTC3833EFE Demo Board | VIN = 4.5V to 24V, VOUT1 = 1.5V @ 15A, RSENSE $125.00
DC1640A-A LTC3833EUDC Demo Board | 4.5V ≤ VIN ≤ 14V, VOUT = 1.5V @ 20A, Inductor DCR Sensing $150.00
DC1640A-B LTC3833EUDC Demo Board | 4.5V ≤ VIN ≤ 14V, VOUT = 1.5V @ 20A, RSENSE $150.00
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
LTC3833IFE#PBF TSSOP-20 I $4.36 $3.05 Yes
LTC3833IFE#TRPBF TSSOP-20 I $3.11 Yes
LTC3833IUDC#PBF 3x4 QFN-20 I $4.14 $2.90 Yes
LTC3833IUDC#TRPBF 3x4 QFN-20 I $2.96 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

  • Distributed Power Systems
  • Point-of-Load Converters
  • Computing Systems
  • Datacomm 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
  • 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:
LTC3833

LTpowerCAD

The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD

To open the project file for this circuit:

Design tools for the following parts are available in LTpowerCAD:
LTC3833

Technical Support