Power Management Switching Regulator Step-Down (Buck) Regulators Internal Power Switch Buck
Power Management Switching Regulator Step-Down (Buck) Regulators High Input Voltage Buck
 Power Management PMIC & Multifunction Multi-Topology DC/DC
 Power Management Switching Regulator Step-Down (Buck) Regulators Buck Regulator Plus LDO

LTC2974 - 4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement

LTC3880 - Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management

LT3694 - 36V, 2.6A Monolithic Buck Regulator With Dual LDO

Features

  • Wide Input Range: 4V to 36V
  • Overvoltage Shutdown Protects Circuit Through 70V Transients
  • 2.6A Output Switching Regulator with Internal Power Switch
  • Dual, Low Dropout, Linear Regulator Controllers with Programmable Current Limit
  • Tracking/Soft-Start Inputs and Power Good Output Simplify Soft-Start and Supply Sequencing
  • Uses Small Inductors and Ceramic Capacitors
  • VOUT(MIN) = 0.75V (Buck and LDOs)
  • Adjustable 250kHz to 2.5MHz Switching Frequency
  • Accurate Enable Threshold Allows User Programmable Undervoltage Lockout
  • Options for Clock Synchronization (LT3694) or Clock Output to Enable Synchronization to Other Switching Regulators (LT3694-1)
  • Thermally Enhanced 28-Lead 4mm × 5mm QFN and 20-Lead TSSOP Packages

Typical Application

LT3694 Typical Application
LT3694 Typical Application

Description

The LT3694/LT3694-1 are monolithic, current mode DC/DC converters with dual, low dropout regulator controllers. The switching converter is a step-down converter capable of generating up to 2.6A at its output. Each regulator has independent track/soft-start circuits simplifying power supply sequencing and interfacing with microcontrollers and DSPs.

The switching frequency is set with a single resistor with a range of 250kHz to 2.5MHz. The high switching frequency permits the use of small inductors and ceramic capacitors leading to very small triple output solutions. The constant switching frequency, combined with low impedance ceramic capacitors, results in low, predictable output ripple. Protection circuitry senses the current in the power switch and external Schottky catch diode to protect the LT3694 against short-circuit conditions. Frequency foldback and thermal shutdown provide additional protection.

With its wide input voltage range of 4V to 36V, the LT3694 regulates a broad array of power sources from 4-cell batteries and 5V logic rails to unregulated wall transformers, lead acid batteries and distributed power supplies. The LT3694 can be synchronized to an external clock with the SYNC pin while the LT3694-1 offers a CLKOUT pin allowing other DC/DC converters to synchronize to the LT3694-1 clock.

Packaging

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

QFN-20, TSSOP-20

LT3694 Package Drawing
LT3694 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LT3694EFE#PBF TSSOP 20 E $5.71 $4.00 View
LT3694EFE#TRPBF TSSOP 20 E $4.06 View
LT3694EFE-1#PBF TSSOP 20 E $5.71 $4.00 View
LT3694EFE-1#TRPBF TSSOP 20 E $4.06 View
LT3694EUFD#PBF QFN 28 E $5.50 $3.85 View
LT3694EUFD#TRPBF QFN 28 E $3.91 View
LT3694EUFD-1#PBF QFN 28 E $5.50 $3.85 View
LT3694EUFD-1#TRPBF QFN 28 E $3.91 View
LT3694IFE#PBF TSSOP 20 I $6.29 $4.40 View
LT3694IFE#TRPBF TSSOP 20 I $4.46 View
LT3694IFE-1#PBF TSSOP 20 I $6.29 $4.40 View
LT3694IFE-1#TRPBF TSSOP 20 I $4.46 View
LT3694IUFD#PBF QFN 28 I $6.06 $4.24 View
LT3694IUFD#TRPBF QFN 28 I $4.30 View
LT3694IUFD-1#PBF QFN 28 I $6.06 $4.24 View
LT3694IUFD-1#TRPBF QFN 28 I $4.30 View
Buy Now • Request 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
DC1541A-A LT3694EFE and LT3694EFE-1 Demo Board $125.00
Buy Now
Click here to view our complete list of demo boards

Applications

  • Automotive
  • Industrial
  • DSL and Cable Modems
  • Distributed Power Regulation
  • Wall Transformer Regulation

People Who Viewed This Product Also Viewed

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.

Simulate

LTspice IV is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. To download LTspice IV and other FREE simulation tools, please visit our Design Simulation page.

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

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

Related models available in LTspice IV
LT3694-1
LT3694

Technical Support