LTC3787 - PolyPhase Synchronous Boost Controller

Features

  • 2-Phase Operation Reduces Required Input and Output Capacitance and Power Supply Induced Noise
  • Synchronous Operation for Highest Efficiency and Reduced Heat Dissipation
  • Wide VIN Range: 4.5V to 38V (40V Abs Max) and Operates Down to 2.5V After Start-Up
  • Output Voltage Up to 60V
  • ±1% 1.200V Reference Voltage
  • RSENSE or Inductor DCR Current Sensing
  • 100% Duty Cycle Capability for Synchronous MOSFET
  • Low Quiescent Current: 135μA
  • Phase-Lockable Frequency (75kHz to 850kHz)
  • Programmable Fixed Frequency (50kHz to 900kHz)
  • Power Good Output Voltage Monitor
  • Low Shutdown Current, IQ < 8μA
  • Internal LDO Powers Gate Drive from VBIAS or EXTVCC
  • Thermally Enhanced Low Profile 28-Pin 4mm × 5mm QFN Package and Narrow SSOP Package
 
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC3787 Typical Application
LTC3787 Typical Application

Description

The LTC3787 is a high performance PolyPhase single output synchronous boost converter controller that drives two N-channel power MOSFET stages out-of-phase. Multiphase operation reduces input and output capacitor requirements and allows the use of smaller inductors than the single-phase equivalent. Synchronous rectification increases efficiency, reduces power losses and eases thermal requirements, enabling high power boost applications.

A 4.5V to 38V input supply range encompasses a wide range of system architectures and battery chemistries. When biased from the output of the boost converter or another auxiliary supply, the LTC3787 can operate from an input supply as low as 2.5V after start-up. The operating frequency can be set for a 50kHz to 900kHz range or synchronized to an external clock using the internal PLL. PolyPhase operation allows the LTC3787 to be configured for 2-, 3-, 4-, 6- and 12-phase operation.

The SS pin ramps the output voltage during start-up. The PLLIN/MODE pin selects Burst Mode® operation, pulse- skipping mode or forced continuous mode at light loads.

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
LTC3787EGN#PBF SSOP-28 GN E 05-08-1641 (GN28) Yes
LTC3787EGN#TRPBF SSOP-28 GN E 05-08-1641 (GN28) Yes
LTC3787EUFD#PBF 4x5 QFN-28 UFD E 05-08-1712 Yes
LTC3787EUFD#TRPBF 4x5 QFN-28 UFD E 05-08-1712 Yes
LTC3787HGN#PBF SSOP-28 GN H 05-08-1641 (GN28) Yes
LTC3787HGN#TRPBF SSOP-28 GN H 05-08-1641 (GN28) Yes
LTC3787HUFD#PBF 4x5 QFN-28 UFD H 05-08-1712 Yes
LTC3787HUFD#TRPBF 4x5 QFN-28 UFD H 05-08-1712 Yes
LTC3787IGN#PBF SSOP-28 GN I 05-08-1641 (GN28) Yes
LTC3787IGN#TRPBF SSOP-28 GN I 05-08-1641 (GN28) Yes
LTC3787IUFD#PBF 4x5 QFN-28 UFD I 05-08-1712 Yes
LTC3787IUFD#TRPBF 4x5 QFN-28 UFD I 05-08-1712 Yes
LTC3787MPGN#PBF SSOP-28 GN MP 05-08-1641 (GN28) Yes
LTC3787MPGN#TRPBF SSOP-28 GN MP 05-08-1641 (GN28) Yes
LTC3787MPUFD#PBF 4x5 QFN-28 UFD MP 05-08-1712 Yes
LTC3787MPUFD#TRPBF 4x5 QFN-28 UFD MP 05-08-1712 Yes


LTC3787 Package Drawing
LTC3787 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
LTC3787EGN#PBF SSOP-28 E $5.04 $3.53 Yes
LTC3787EGN#TRPBF SSOP-28 E $3.59 Yes
LTC3787EUFD#PBF 4x5 QFN-28 E $5.04 $3.53 Yes
LTC3787EUFD#TRPBF 4x5 QFN-28 E $3.59 Yes
LTC3787HGN#PBF SSOP-28 H $6.13 $4.29 Yes
LTC3787HGN#TRPBF SSOP-28 H $4.35 Yes
LTC3787HUFD#PBF 4x5 QFN-28 H $6.13 $4.29 Yes
LTC3787HUFD#TRPBF 4x5 QFN-28 H $4.35 Yes
LTC3787IGN#PBF SSOP-28 I $5.71 $4.00 Yes
LTC3787IGN#TRPBF SSOP-28 I $4.06 Yes
LTC3787IUFD#PBF 4x5 QFN-28 I $5.71 $4.00 Yes
LTC3787IUFD#TRPBF 4x5 QFN-28 I $4.06 Yes
LTC3787MPGN#PBF SSOP-28 MP $16.80 $11.76 Yes
LTC3787MPGN#TRPBF SSOP-28 MP $11.82 Yes
LTC3787MPUFD#PBF 4x5 QFN-28 MP $16.80 $11.76 Yes
LTC3787MPUFD#TRPBF 4x5 QFN-28 MP $11.82 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
DC1411A LTC3787EUFD Demo Board | 5V to 24Vin to 24Vout at 6A $150.00
DC2001A LTC3787EUFD Demo Board | LTC3787(x2) Paralleled Boost Controllers, 6V ≤ Vin ≤ 24V, Vout = 24V @ Up to 30A $250.00
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
LTC3787HGN#PBF SSOP-28 H $6.13 $4.29 Yes
LTC3787HGN#TRPBF SSOP-28 H $4.35 Yes
LTC3787HUFD#PBF 4x5 QFN-28 H $6.13 $4.29 Yes
LTC3787HUFD#TRPBF 4x5 QFN-28 H $4.35 Yes
LTC3787IGN#PBF SSOP-28 I $5.71 $4.00 Yes
LTC3787IGN#TRPBF SSOP-28 I $4.06 Yes
LTC3787IUFD#PBF 4x5 QFN-28 I $5.71 $4.00 Yes
LTC3787IUFD#TRPBF 4x5 QFN-28 I $4.06 Yes
LTC3787MPGN#PBF SSOP-28 MP $16.80 $11.76 Yes
LTC3787MPGN#TRPBF SSOP-28 MP $11.82 Yes
LTC3787MPUFD#PBF 4x5 QFN-28 MP $16.80 $11.76 Yes
LTC3787MPUFD#TRPBF 4x5 QFN-28 MP $11.82 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

  • Industrial
  • Automotive
  • Medical
  • Military
 

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Design Tools

LTspice

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Models for the following parts are available in LTspice:
LTC3787

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:
LTC3787
LTC3787 Parallel

Technical Support