LTC3853 - Triple Output, Multiphase Synchronous Step-Down Controller
Features
- Triple, 120° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- Configurable as a 180° Dual Phase Controller Plus a Single Phase Controller
- The Third Phase Can Regulate Up to a 13.5V Output
- High Efficiency: Up to 92%
- RSENSE or DCR Current Sensing
- ±0.75% 0.8V Output Voltage Accuracy
- Phase-Lockable Fixed Frequency 250kHz to 750kHz
- Supports Pre-Biased Outputs
- Dual N-Channel MOSFET Synchronous Drive
- Wide VIN Range: 4.5V to 24V Operation (28V Abs Max)
- Adjustable Soft-Start Current Ramping or Tracking
- Foldback Output Current Limiting
- Output Overvoltage Protection
- Dual Power Good Output Voltage Monitors
- 40-Lead 6mm × 6mm QFN Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC®3853 is a high performance triple output stepdown switching regulator controller that drives all Nchannel synchronous power MOSFET stages. Power loss and supply noise are minimized by operating the output stages out of phase. The part can be configured as a dual phase controller plus a single phase controller if needed. The part can also be configured to provide a single 3-phase output for even higher output currents.
A wide 4.5V to 24V (28V maximum) input voltage supply range encompasses most battery chemistries and intermediate bus voltages. Phase 3 can regulate output voltages up to 13.5V. A constant-frequency current mode architecture allows for a phase-lockable frequency up to 750kHz.
Independent TK/SS pins for each output ramps the output voltages and can be configured for coincident or ratiometric tracking. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode® operation, pulse-skipping or continuous inductor current modes.
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 |
|---|---|---|---|---|---|
| LTC3853EUJ#PBF | 6x6 QFN-40 | UJ | E | 05-08-1728 | Yes |
| LTC3853EUJ#TRPBF | 6x6 QFN-40 | UJ | E | 05-08-1728 | Yes |
| LTC3853HUJ#PBF | 6x6 QFN-40 | UJ | H | 05-08-1728 | Yes |
| LTC3853HUJ#TRPBF | 6x6 QFN-40 | UJ | H | 05-08-1728 | Yes |
| LTC3853IUJ#PBF | 6x6 QFN-40 | UJ | I | 05-08-1728 | Yes |
| LTC3853IUJ#TRPBF | 6x6 QFN-40 | UJ | I | 05-08-1728 | Yes |
| LTC3853MPUJ#PBF | 6x6 QFN-40 | UJ | MP | 05-08-1728 | Yes |
| LTC3853MPUJ#TRPBF | 6x6 QFN-40 | UJ | MP | 05-08-1728 | 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 | |
|---|---|---|---|---|---|---|
| LTC3853EUJ#PBF | 6x6 QFN-40 | E | $5.04 | $3.53 | Yes | |
| LTC3853EUJ#TRPBF | 6x6 QFN-40 | E | $3.59 | Yes | ||
| LTC3853HUJ#PBF | 6x6 QFN-40 | H | $6.06 | $4.24 | Yes | |
| LTC3853HUJ#TRPBF | 6x6 QFN-40 | H | $4.30 | Yes | ||
| LTC3853IUJ#PBF | 6x6 QFN-40 | I | $5.63 | $3.94 | Yes | |
| LTC3853IUJ#TRPBF | 6x6 QFN-40 | I | $4.00 | Yes | ||
| LTC3853MPUJ#PBF | 6x6 QFN-40 | MP | $15.22 | $10.65 | Yes | |
| LTC3853MPUJ#TRPBF | 6x6 QFN-40 | MP | $10.71 | 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 |
|---|---|---|---|
| DC1254A | LT3853EUJ Demo Board | Triple, PolyPhase, 6.5V ≤ VIN ≤ 24V, Vout1 = 2.5V/5A, Vout2 = 1.8V/5A, Vout3 = 3.3V/5A | $250.00 | |
| DC1349A | LTC3853EUJ Demo Board | Triple, PolyPhase, 6.5V ≤ VIN ≤ 14V, Vout1 = 1.8V/15A, Vout2 = 1.2V/15A, Vout3 = 2.5V/15A | $250.00 | |
| Buy Now | |||
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 | |
|---|---|---|---|---|---|---|
| LTC3853HUJ#PBF | 6x6 QFN-40 | H | $6.06 | $4.24 | Yes | |
| LTC3853HUJ#TRPBF | 6x6 QFN-40 | H | $4.30 | Yes | ||
| LTC3853IUJ#PBF | 6x6 QFN-40 | I | $5.63 | $3.94 | Yes | |
| LTC3853IUJ#TRPBF | 6x6 QFN-40 | I | $4.00 | Yes | ||
| LTC3853MPUJ#PBF | 6x6 QFN-40 | MP | $15.22 | $10.65 | Yes | |
| LTC3853MPUJ#TRPBF | 6x6 QFN-40 | MP | $10.71 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
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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
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LTC3853
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.
