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
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 |
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 | ||
| Buy Now • Request Samples | ||||||
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 | Contact Factory | |
| 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 | Contact Factory | |
| Buy Now | |||
Applications
- FPGAs and Processor Power
- Servers and Computing
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Design Tools
Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:
- LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
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- LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
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- Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
- LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
- And More!
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
