LTC3855 - Dual, Multiphase Synchronous DC/DC Controller with Differential Remote Sense
- Dual, 180° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- High Efficiency: Up to 95%
- RSENSE or DCR Current Sensing
- Programmable DCR Temperature Compensation
- ±0.75% 0.6V Output Voltage Accuracy
- Phase-Lockable Fixed Frequency 250kHz to 770kHz
- True Remote Sensing Differential Amplifier
- Dual N-Channel MOSFET Synchronous Drive
- Wide VIN Range: 4.5V to 38V
- VOUT Range: 0.6V to 12.5V without Differential Amplifier
- VOUT Range: 0.6V to 3.3V with Differential Amplifier
- Clock Input and Output for Up to 12-Phase Operation
- Adjustable Soft-Start or VOUT Tracking
- Foldback Output Current Limiting
- Output Overvoltage Protection
- 40-Pin (6mm × 6mm) QFN and 38-Lead FE Packages
AEC-Q100 data available for specific packages
The LTC3855 is a dual PolyPhase current mode synchronous step-down switching regulator controller that drives all N-channel power MOSFET stages. It includes a high speed differential remote sense amplifier. The maximum current sense voltage is programmable for either 30mV, 50mV or 75mV, allowing the use of either the inductor DCR or a discrete sense resistor as the sensing element.
The LTC3855 features a precision 0.6V reference and can produce output voltages up to 12.5V. A wide 4.5V to 38V input supply range encompasses most intermediate bus voltages and battery chemistries. Power loss and supply noise are minimized by operating the two controller output stages out of phase. Burst Mode operation, continuous or pulse-skipping modes are supported.
The LTC3855 can be configured for up to 12-phase operation, has DCR temperature compensation, two power good signals and two current limit set pins. The LTC3855 is available in low profile 40-pin 6mm × 6mm QFN and 38-lead exposed pad FE packages.
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 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
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Demo BoardsLinear 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.
|DC1441A||LTC3855EUJ Demo Board | Dual Output, VIN = 4.5V to 14V, VOUT1 = 1.8V @ 17A, VOUT2 = 1.2V @ 17A||$200.00|
|DC1586A||LTC3855EUJ Demo Board | Dual Output, VIN = 4.5V to 25V, VOUT1 = 3.3V @ 5A, VOUT2 = 2.5V @ 5A||$200.00|
|DC1617A-A||LTC3855EFE Demo Board | Dual Output VIN = 4.5V to 26V, VOUT1 = 2.5V @ 15A, VOUT2 = 1.8V @ 15A||$200.00|
|DC1617A-B||LTC3855EFE Demo Board | Dual Output VIN = 13V to 36V, VOUT1 = 12V @ 6A, VOUT2 = 5V @ 10A||$200.00|
Designed for Automotive and Transportation ApplicationsAEC-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
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- Computer Systems
- Telecom Systems
- Industrial and Medical Instruments
- DC Power Distribution Systems
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