LTC3835 - Low IQ Synchronous Step-Down Controller

Features

  • Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 10V
  • Low Operating Quiescent Current: 80μA
  • OPTI-LOOP® Compensation Minimizes COUT
  • 1% Output Voltage Accuracy
  • Wide VIN Range: 4V to 36V Operation
  • Phase-Lockable Fixed Frequency 140kHz to 650kHz
  • Dual N-Channel MOSFET Synchronous Drive
  • Very Low Dropout Operation: 99% Duty Cycle
  • Adjustable Output Voltage Soft-Start or Tracking
  • Output Current Foldback Limiting
  • Power Good Output Voltage Monitor
  • Clock Output for PolyPhase® Applications
  • Output Overvoltage Protection
  • Low Shutdown IQ: 10μA
  • Internal LDO Powers Gate Drive from VIN or VOUT
  • Selectable Continuous, Pulse-Skipping or Burst Mode® Operation at Light Loads
  • Small 20-Lead TSSOP or 4mm × 5mm QFN Package

Typical Application

LTC3835 Typical Application
LTC3835 Typical Application

Description

The LTC3835 is a high performance step-down switching regulator controller that drives an all N-channel synchronous power MOSFET stage. A constant-frequency current mode architecture allows a phase-lockable frequency of up to 650kHz.

The 80μA no-load quiescent current extends operating life in battery powered systems. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3835 features a precision 0.8V reference and a power good output indicator. The 4V to 36V input supply range encompasses a wide range of battery chemistries.

The TRACK/SS pin ramps the output voltage during startup. Current foldback limits MOSFET heat dissipation during short-circuit conditions.

 CLKOUT/PHASMDEXTVCCPGOODPackage
LTC3835 Yes  Yes  Yes  TSSOP-20, 4x5 QFN-20
LTC3835-1 No  No  No  GN-16, 3x5 DFN-16

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
LTC3835EFE#PBF TSSOP-20 FE E 05-08-1663 (CB) Yes
LTC3835EFE#TRPBF TSSOP-20 FE E 05-08-1663 (CB) Yes
LTC3835EUFD#PBF 4x5 QFN-20 UFD E 05-08-1711 Yes
LTC3835EUFD#TRPBF 4x5 QFN-20 UFD E 05-08-1711 Yes
LTC3835IFE#PBF TSSOP-20 FE I 05-08-1663 (CB) Yes
LTC3835IFE#TRPBF TSSOP-20 FE I 05-08-1663 (CB) Yes
LTC3835IUFD#PBF 4x5 QFN-20 UFD I 05-08-1711 Yes
LTC3835IUFD#TRPBF 4x5 QFN-20 UFD I 05-08-1711 Yes


LTC3835 Package Drawing
LTC3835 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
LTC3835EFE#PBF TSSOP-20 E $5.07 $3.55 Yes
LTC3835EFE#TRPBF TSSOP-20 E $3.61 Yes
LTC3835EUFD#PBF 4x5 QFN-20 E $5.07 $3.55 Yes
LTC3835EUFD#TRPBF 4x5 QFN-20 E $3.61 Yes
LTC3835IFE#PBF TSSOP-20 I $6.14 $4.30 Yes
LTC3835IFE#TRPBF TSSOP-20 I $4.36 Yes
LTC3835IUFD#PBF 4x5 QFN-20 I $6.14 $4.30 Yes
LTC3835IUFD#TRPBF 4x5 QFN-20 I $4.35 Yes
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* 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
DC967B LTC3835EFE Demo Board | 4.5V ≤ VIN ≤ 36V, Vout = 3.3V @ 5A Contact Factory
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Click here to view our complete list of demo boards

Applications

  • Automotive Systems
  • Telecom Systems
  • Battery-Operated Digital Devices
  • Distributed DC 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
  • 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:
LTC3835
LTC3835-1

Technical Support