LTC3727-1 - High Efficiency, 2-Phase Synchronous Step-Down Switching Regulators

Features

  • Wide Output Voltage Range:
    0.8V < or = VOUT < or = 14V
  • Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
  • OPTI-LOOP® Compensation Minimizes COUT
  • ±1% Output Voltage Accuracy
  • Power Good Output Voltage Monitor
  • Phase-Lockable Fixed Frequency 250kHz to 550kHz
  • Latched Short-Circuit Shutdown (LTC3727 Only)
  • Dual N-Channel MOSFET Synchronous Drive
  • Wide VIN Range: 4V to 36V Operation
  • Very Low Dropout Operation: 99% Duty Cycle
  • Adjustable Soft-Start Current Ramping
  • Foldback Output Current Limiting
  • Output Overvoltage Protection
  • Low Shutdown IQ: 20µA
  • Selectable Constant Frequency or Burst Mode® Operation
  • Small 28-Lead SSOP Package
  • LTC3727-1 Also Available in the 5mm x 5mm QFN Package
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC3727-1 Typical Application

Description

The LTC3727/LTC3727-1 are high performance dual step-down switching regulator controllers that drive all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows phase-lockable frequency of up to 550kHz. Power loss and noise due to the ESR of the input capacitors are minimized by operating the two controller output stages out of phase.

OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. There is a precision 0.8V reference and a power good output indicator. A wide 4V to 30V (36V maximum) input supply range encompasses all battery chemistries.

A RUN/SS pin for each controller provides soft-start, and on the LTC3727GN, optional timed, short-circuit shutdown. Current foldback limits MOSFET heat dissipation during short-circuit conditions when overcurrent latchoff is disabled. Output overvoltage protection circuitry latches on the bottom MOSFET until VOUT returns to normal. The FCB mode pin can select among Burst Mode, constant frequency mode and continuous inductor current mode or regulate a secondary winding.

  Vin Range
Vref Accuracy Over Temp
Latch-Off Min On-Time
LTC3727 4V - 36V ±1% No 180ns
LTC3727-1 4V - 36V ±1% Yes 180ns
LTC3727A-1 4V - 36V ±1% No 120ns
LTC3727LX-1 4V - 32V ±1.5% No 120ns

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
LTC3727EG-1#PBF SSOP-28 G E 05-08-1640 (G28) Yes
LTC3727EG-1#TRPBF SSOP-28 G E 05-08-1640 (G28) Yes
LTC3727EUH-1#PBF 5x5 QFN-32 UH E 05-08-1693 Yes
LTC3727EUH-1#TRPBF 5x5 QFN-32 UH E 05-08-1693 Yes
LTC3727IG-1#PBF SSOP-28 G I 05-08-1640 (G28) Yes
LTC3727IG-1#TRPBF SSOP-28 G I 05-08-1640 (G28) Yes


LTC3727-1 Package Drawing
LTC3727-1 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
LTC3727EG-1#PBF SSOP-28 E $6.93 $4.85 Yes
LTC3727EG-1#TRPBF SSOP-28 E $4.95 Yes
LTC3727EUH-1#PBF 5x5 QFN-32 E $7.21 $5.05 Yes
LTC3727EUH-1#TRPBF 5x5 QFN-32 E $5.15 Yes
LTC3727IG-1#PBF SSOP-28 I $8.43 $5.90 Yes
LTC3727IG-1#TRPBF SSOP-28 I $5.96 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.

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
LTC3727IG-1#PBF SSOP-28 I $8.43 $5.90 Yes
LTC3727IG-1#TRPBF SSOP-28 I $5.96 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

  • Telecom Systems
  • Automotive Systems
  • Battery-Operated Digital Devices

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:
LTC3727
LTC3727-1
LTC3727A-1
LTC3727LX-1

Technical Support