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LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution

Posted by: Yoyokuo 2022-10-24 Comments Off on LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution

Linear’s LTC3787 is a high-performance multi-phase single-output synchronous boost power converter controller that can drive two N-channel power MOSFETs. Input voltage 4.5V-38V, output voltage up to 60V, ±1% 1.200V reference voltage, available Program fixed frequency 50kHz to 900kHz, quiescent current 135uA, mainly used in industrial, automotive, medical equipment and military. This article introduces the LTC3787 main features, block diagram, 12-phase operation connection diagram and high efficiency 2-phase 24V, 46V and 48V boost converters Circuit diagram, 4-phase single output boost converter circuit diagram, demo board DC1411A main performance characteristics, circuit diagram, bill of materials and PCB component layout.

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, pulseskipping mode or forced continuous mode at light loads.

LTC3787 main 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 MOSFETs

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 4mmx 5mm

QFN Package and Narrow SSOP Package

LTC3787 applications:

Industrial

Automotive

Medical

Military
LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
Figure 1. LTC3787 block diagram
LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
Figure 2. LTC3787 12-Phase Operating Connection Diagram
LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
Figure 3. LTC3787 High Efficiency 2-Phase 24V Boost Converter Circuit Diagram
LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
Figure 4. LTC3787 High Efficiency 2-Phase 48V Boost Converter Circuit Diagram
LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
Figure 5. LTC3787 High Efficiency 2-Phase 36V Boost Converter Circuit Diagram
LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
Figure 6. LTC3787 High Efficiency 2-Phase 48V Boost Converter Circuit Diagram
LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
Figure 7. LTC3787 Circuit Diagram for High Efficiency 2-Phase 24V Boost Converter with Inductive DCR Current Sensing
LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
Figure 8. LTC3787 4-Phase Single Output Boost Converter Circuit Diagram
The main performance characteristics of the demo board DC1411A:
LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
Figure 9. Demo board DC1411A circuit diagram: input 5-24V, output 24V/6A
Demo board DC1411A bill of materials:

Qty

Reference

Part Description

Manufacturer / Part #

REQUIRED CIRCUIT components:

3

CIN1,COUT5,COUT10

CAP., 150uF, 35V, EP-cap

SUNCON, 35HVH150M

12

COUT1, COUT2, COUT3, COUT4, COUT6, COUT7, COUT8, COUT9, CIN2, CIN3, CIN4, CIN5

Cap., X5R, 22uF 25V, 20%, 1812

TDK, C4532X5R1E226M

1

C2,

Cap., NPO, 100pF, 25V, 10%, 0603

AVX, 06033A101KAT

1

C3

Cap.,X7R, 15nF, 25V, 10%,0603

AVX, 06033C153KAT

4

C4,C9,C15,C16

Cap., X5R, 0.1uF, 25V, 10%, 0603

AVX, 06033D104KAT2A

3

C5,C10,C18

Cap., NPO, 1000pF, 25V, 10%, 0603

AVX, 06033A102KAT

1

C8

Cap., X5R, 4.7uF, 25V, 10%, 0805

TaiyoYuden, TMK212BJ475KG-T

2

D1, D2

DIODE, 30V, SOD323

Infineon, BAS140W

2

L1,L2

Inductor, 3.3uH

PULSE-PA1494.362NL

2

Q2,Q8

MOSFET, N Chanel, LFPAK

RENESAS, RJK0452DPB

2

Q4,Q6

MOSFET, N Chanel, LFPAK

RENESAS, RJK0453DPB

4

RSNS1,RSNS2,RSNS3,RSNS4

Res., Chip, 0.008, 1%, 2010

VISHAY, WSL20108L000FEA

6

R2,R3,R5,R7,R15,R18

Res., Chip, 0 Ohm, 1%, 0603

VISHAY, CRCW06030000Z0EA

1

R6

Res., Chip, 232K, 1%, 0603

VISHAY, CRCW0603232KFKED

3

R8,R9,R34

Res., Chip, 12.1K, 1%, 0603

VISHAY, CRCW060312K1FKEA

4

R11,R16,R35,R36

Res., Chip, 10K, 1%, 0603

VISHAY, CRCW060310KFKEA

4

R13,R17,R19,R21

Res., Chip, 10, 1%, 0603

VISHAY, CRCW060310R0FKEA

2

R26,C17

Res., Chip, 100K, 1%, 0603

VISHAY, CRCW0603100KFKEA

1

R32

Res., Chip, 2.21, 1%, 0603

VISHAY, CRCW06032R21FNEA

1

R33

Res., Chip, 38.3K ,1%, 0603

VISHAY, CRCW060338K3FKEA

1

U1

IC LTC3787EUFD QFN28 – 4X5

Linear Tech., LTC3787EUFD

ADDITIONAL DEMO BOARD CIRCUIT COMPONENTS:

0

C1,C19,C20

OPT, 0603

0

Q1,Q3,Q5,Q7

OPT, LFPAK

0

R1,R4,R10,R31

OPT, 0603

HARDWARE-FOR DEMO BOARD ONLY:

11

E1,E5,E6,E7,E8,E11,E12,E13,E14,E15,E21

Turret, Testpoint, 091″

Mill Max 2501-2-00-80-00-00-07-0

2

E2,E4

JACK BANANA

KEYSTONE, 575-4

2

E9,E10

STUD, TEST PIN

PEM KFH-032-10

4

(E9,E10)X2

NUT, BRASS NUTS # 10-32

ANY #10-32

2

E9,E10

RING, LUG RING # 10

KEYSTONE #10

2

E9,E10

WASHER, TIN PLATED BRASS

ANY #10

2

JP1, JP5

Headers, 4 Pins 2mm Ctrs.

Samtec TMM-104-02-LS

1

JP2

Headers, 3 Pins 2mm Ctrs.

Samtec TMM-103-02-LS

4

XJP1-XJP2

Shunt, 2mm Ctrs.

Samtec 2SN-BK-G

4

STAND-OFF, NYLON 0.5″ tall

KEYSTONE, 8833(SNAP ON)

LinearLTC3787 Multiphase Single Output Boost Power Conversion Solution
Figure 10. Demo Board DC1411A PCB Component Layout: Top Layer

Figure 11. Demo Board DC1411A PCB Component Layout: Bottom Layer
For details, see:
http://cds.linear.com/docs/Datasheet/3787fc.pdf
and
http://cds.linear.com/docs/Demo%20Board%20Manual/dc1411A.pdf

The Links:   LMG6911RPBC-D MG150J7KS50