LTC7811

RECOMMENDED FOR NEW DESIGNS

40V, Low I_Q, 3MHz, Triple Output Buck/Buck/Boost Controller

Data Sheet (Rev. A) Product Selection Table

Part Models: 6
1ku List Price: Starting From $3.62

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Part Details

Dual Synchronous Buck Plus Single Boost Controllers
Low Operating I_Q:
- 14μA (14V to 3.3V, Channel 1 On)
Outputs Remain in Regulation Through Cold Crank Down to 1V Input Supply Voltage
Wide Bias Input Voltage Range: 4.5V to 40V
Buck Output Voltages Up to 40V
Boost Output Voltage Limited Only by External Components
Spread Spectrum Operation

R_SENSE or DCR Current Sensing
Low Battery Indicator for Automotive Applications
Programmable Fixed Frequency (100kHz to 3MHz)
Phase-Lockable Frequency (100kHz to 3MHz)
Selectable Continuous, Pulse-Skipping, or Low Ripple Burst Mode^® Operation at Light Loads
Boost Channel Current Monitor Output
Low Shutdown I_Q: 1.5μA
Small 40-Lead 6mm × 6mm QFN Package
AEC-Q100 Qualified for Automotive Applications

Part Models: 6
1ku List Price: Starting From $3.62

Documentation

Data Sheet 1

LTC7811: 40V, Low I_Q, 3MHz, Triple Output Buck/Buck/Boost Controller Data Sheet (Rev.A) 04/05/2021

User Guide 1

DC3151A - Demo Manual (Rev.0) 07/19/2021

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.

Part Model	Pin/Package Drawing	Documentation	CAD Symbols, Footprints, and 3D Models
LTC7811IUJ#PBF	40-Lead QFN (6mm x 6mm x 0.75mm w/ EP)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC7811IUJ#TRPBF	40-Lead QFN (6mm x 6mm x 0.75mm w/ EP)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC7811IUJ#WPBF	40-Lead QFN (6mm x 6mm x 0.75mm w/ EP)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC7811IUJ#WTRPBF	40-Lead QFN (6mm x 6mm x 0.75mm w/ EP)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC7811JUJ#WPBF	40-Lead QFN (6mm x 6mm x 0.75mm w/ EP)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC7811JUJ#WTRPBF	40-Lead QFN (6mm x 6mm x 0.75mm w/ EP)	Material Declaration Reliablity Data	Ultra Librarian SamacSys

This is the most up-to-date revision of the Data Sheet.

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Evaluation Kits

LTC7811 | Triple Output Step-Up/Dual Step-Down Power Supply

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Product Details

Demonstration circuit DC3151A is a non-synchronous boost plus dual synchronous buck power supply featuring the LTC7811. The demonstration circuit is designed for two buck outputs 5V/10A, 3.3V/7A supplied by a boosted 9.5V output. Benefiting from this feature, the buck outputs can maintain regulation over a wide input voltage range of 4.5V to 36V which is suitable for automotive or other battery fed applications. Also, the demonstration circuit uses a drop-in layout whereas the main buck circuit components fit in an area of ¾" by 1½", while the main boost circuit area is ¾" by 1¾". The package style for the LTC7811 is a 40-pin exposed pad QFN.

The main features of the board include rail tracking (Buck channels only), an internal 5V linear regulator for bias, separate RUN pins for each output, a PGOOD signal (CH1 only), battery monitor and a Mode selector that allow the converter to run in CCM, Pulse-skipping or Burst Mode operation. Spread Spectrum Mode is available for EMI improvement. Synchronization to an external clock is also possible.

The LTC7811 datasheet gives a complete description of this part, its operation and application information. The datasheet must be read in conjunction with the quick start guide for demo circuit 3151.