LTC3877 -Dual Phase Step-Down Synchronous Controller with VID Output Voltage Programming and Low Value DCR Sensing

Features

  • 6-Bit Parallel VID (Voltage Identification) Inputs Set Output Voltage from 0.6V to 1.23V in 10mV Steps
  • Output Voltage Range: 0.6V to 5V (Without VID)
  • Ultra Low Value DCR/RSENSE Current Sensing
  • ±1% Maximum Total Regulation Voltage Accuracy Over Temperature
  • Dual Differential Remote Sensing Amplifiers
  • tON(MIN) = 40ns, Capable of Very Low Duty Cycles at High Frequency
  • Phase-Lockable Frequency from 250kHz to 1MHz
  • Current Mismatch Between Channels: 5% Max
  • Adjustable Soft-Start Current Ramping or Tracking
  • Multi-IC Operation Up To 12 Phases
  • Wide VIN Range: 4.5V to 38V
  • Dual Power Good Output Voltage Monitors
  • Output Overvoltage Protection
  • Foldback Output Current Limiting and Soft Recovery

Typical Application

LTC3877 Typical Application
LTC3877 Typical Application

Description

The LTC®3877 is a VID-programmable, constant frequency current mode step-down controller using an advanced and proprietary architecture. This new architecture enhances the signal-to-noise ratio of the current sense signal, allowing the use of very low DC resistance power inductors to maximize efficiency in high current applications. This feature also dramatically reduces the current sensing error, so that current sharing is greatly improved in multi-phase low DCR applications. In addition, the controller achieves a minimum on-time of just 40ns, permitting the use of high switching frequency at high step-down ratios.

The LTC3877 features dual high speed remote sense differential amplifiers, programmable current sense limits and DCR temperature compensation to limit the maximum output current precisely over temperature. The LTC3877 also features a precise 0.6V reference with guaranteed accuracy of ±0.5%. The LTC3877 is available in a low profile 44-lead 7mm × 7mm QFN package.

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
LTC3877EUK#PBF 7x7 QFN-44 UK E 05-08-1763 Yes
LTC3877EUK#TRPBF 7x7 QFN-44 UK E 05-08-1763 Yes
LTC3877IUK#PBF 7x7 QFN-44 UK I 05-08-1763 Yes
LTC3877IUK#TRPBF 7x7 QFN-44 UK I 05-08-1763 Yes


LTC3877 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
LTC3877EUK#PBF 7x7 QFN-44 E $5.63 $3.94 Yes
LTC3877EUK#TRPBF 7x7 QFN-44 E $4.00 Yes
LTC3877IUK#PBF 7x7 QFN-44 I $6.06 $4.24 Yes
LTC3877IUK#TRPBF 7x7 QFN-44 I $4.30 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
DC2229A-A LTC3877 Demo Board | Dual Buck Controller, Sub-mΩ DCR sensing, 6V ≤ VIN ≤ 14V, Vout1 is VID Prog from 0.6V to 1.23V @ 30A, Vout2 is 1.5V @ 30A $150.00
DC2229A-B LTC3877/LTC3874 Demo Board | 4-Phase Buck Controller with VID Inputs, Sub-mΩ DCR sensing, 6V ≤ VIN ≤ 14V, Vout = 0.6V to 1.23V at 120A $150.00
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Applications

  • FPGAs and Processor Power
  • Servers and Computing

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