LTC3859A

Name: LTC3859A
Brand: Analog Devices
Price: 6.84 USD
Availability: InStock

PRODUCTION

Low I_Q, Triple Output, Buck/Buck/Boost Synchronous Controller with Improved Burst Mode Operation

Data Sheet (Rev. B) Product Selection Table

Part Models: 16
1ku List Price: Starting From $6.57

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Overview

Dual Buck Plus Single Boost Synchronous Controllers
Outputs Remain in Regulation Through Cold Crank Down to 2.5V
Low Operating I_Q: 55μA (One Channel On)
Wide Bias Input Voltage Range: 4.5V to 38V
Buck Output Voltage Range: 0.8V ≤ V_OUT ≤ 24V
Boost Output Voltage Up to 60V
R_SENSE or DCR Current Sensing
100% Duty Cycle for Boost Synchronous MOSFET Even in Burst Mode^® Operation
Phase-Lockable Frequency (75kHz to 850kHz)

Programmable Fixed Frequency (50kHz to 900kHz)
Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode Operation at Light Loads
Very Low Buck Dropout Operation: 99% Duty Cycle
Adjustable Output Voltage Soft-Start or Tracking
Low Shutdown I_Q: 14μA
Small 38-Pin 5mm × 7mm QFN and TSSOP Packages

The LTC3859A is a high performance triple output (buck/buck/boost) synchronous DC/DC switching regulator controller that drives all N-channel power MOSFET stages. Constant frequency current mode architecture allows a phase-lockable switching frequency of up to 850kHz. The LTC3859A operates from a wide 4.5V to 38V input supply range. When biased from the output of the boost converter or another auxiliary supply, the LTC3859A can operate from an input supply as low as 2.5V after start-up.

The 55μA no-load quiescent current extends operating runtime in battery powered systems. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3859A features a precision 0.8V reference for the bucks, 1.2V reference for the boost and a power good output indicator. The PLLIN/MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode at light loads.

Compared to the LTC3859, the LTC3859A's boost controller has improved performance in Burst Mode operation when the input voltage is higher than the regulated output voltage.


	Quiescent Current (Burst Mode)	Notes
LTC3859AL	28μA-One channel on, Buck 38μA-All three channels on	Internal clamp on the INTVCC pin
LTC3859A	55μA-One channel on, Buck 80μA-All three channels on	Internal clamp on the INTVCC pin. For new designs, we recommend LTC3859AL
LTC3859	55μA-One channel on, Buck 80μA-All three channels on	For new designs, we recommend LTC3859AL

Applications

Automotive Always-On and Start-Stop Systems
Battery Operated Digital Devices
Distributed DC Power Systems
Multioutput Buck-Boost Applications

Part Models: 16
1ku List Price: Starting From $6.57

Documentation

Data Sheet 1

LTC3859A: Low I_Q, Triple Output, Buck/Buck/Boost Synchronous Controller with Improved Burst Mode Operation Data Sheet (Rev.B) 06/29/2016

User Guide 1

DC1425A - Demo Manual 05/03/2012

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
LTC3859AEFE#PBF	38-Lead TSSOP w/ EP	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AEFE#TRPBF	38-Lead TSSOP w/ EP	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AEUHF#PBF	38-Lead QFN (5mm x 7mm w/ EP)	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AEUHF#TRPBF	38-Lead QFN (5mm x 7mm w/ EP)	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AHFE#PBF	38-Lead TSSOP w/ EP	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AHFE#TRPBF	38-Lead TSSOP w/ EP	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AHUHF#PBF	38-Lead QFN (5mm x 7mm w/ EP)	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AHUHF#TRPBF	38-Lead QFN (5mm x 7mm w/ EP)	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AIFE#PBF	38-Lead TSSOP w/ EP	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AIFE#TRPBF	38-Lead TSSOP w/ EP	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AIUHF#PBF	38-Lead QFN (5mm x 7mm w/ EP)	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AIUHF#TRPBF	38-Lead QFN (5mm x 7mm w/ EP)	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AMPFE#PBF	38-Lead TSSOP w/ EP	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AMPFE#TRPBF	38-Lead TSSOP w/ EP	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AMPUHF#PBF	38-Lead QFN (5mm x 7mm w/ EP)	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys
LTC3859AMPUHF#TRPBF	38-Lead QFN (5mm x 7mm w/ EP)	Material Declaration Reliability Report Package Resources	Ultra Librarian SamacSys

Part Models	Product Lifecycle	PCN

May 18, 2026 - 26_0072 Epoxy Change for Select TSSOP Products
		PCN26_0072_Form Material_Report
LTC3859AEFE#PBF	PRODUCTION
LTC3859AEFE#TRPBF	PRODUCTION
LTC3859AHFE#PBF	PRODUCTION
LTC3859AHFE#TRPBF	PRODUCTION
LTC3859AIFE#PBF	PRODUCTION
LTC3859AIFE#TRPBF	PRODUCTION
LTC3859AMPFE#PBF	PRODUCTION
LTC3859AMPFE#TRPBF	PRODUCTION
Apr 6, 2022 - 22_0068 Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL
		PCN22_0068_Form Material_Report
LTC3859AEFE#PBF	PRODUCTION
LTC3859AEFE#TRPBF	PRODUCTION
LTC3859AHFE#PBF	PRODUCTION
LTC3859AHFE#TRPBF	PRODUCTION
LTC3859AIFE#PBF	PRODUCTION
LTC3859AIFE#TRPBF	PRODUCTION
LTC3859AMPFE#PBF	PRODUCTION
LTC3859AMPFE#TRPBF	PRODUCTION
Jul 31, 2020 - 20_0245 Notification of Wafer Fab Location Change for 0.6µm BICMOS Process Devices from ADI Milpitas (Hillview) to Vanguard Int. (Taiwan)
		PCN20_0245_Form Material_Report Delta Qualification Matrix Other Qualification Results Summary
LTC3859AEFE#PBF	PRODUCTION
LTC3859AEFE#TRPBF	PRODUCTION
LTC3859AEUHF#PBF	PRODUCTION
LTC3859AEUHF#TRPBF	PRODUCTION
LTC3859AHFE#PBF	PRODUCTION
LTC3859AHFE#TRPBF	PRODUCTION
LTC3859AHUHF#PBF	PRODUCTION
LTC3859AHUHF#TRPBF	PRODUCTION
LTC3859AIFE#PBF	PRODUCTION
LTC3859AIFE#TRPBF	PRODUCTION
LTC3859AIUHF#PBF	PRODUCTION
LTC3859AIUHF#TRPBF	PRODUCTION
LTC3859AMPFE#PBF	PRODUCTION
LTC3859AMPFE#TRPBF	PRODUCTION
LTC3859AMPUHF#PBF	PRODUCTION
LTC3859AMPUHF#TRPBF	PRODUCTION

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

Software Resources

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Hardware Ecosystem

Parts	Product Life Cycle	Description
Circuit Monitors 1
LTC2960	RECOMMENDED FOR NEW DESIGNS	36V Nano-Current Two-Input Voltage Monitor
Hot Swap Controllers 1
LTC4364	RECOMMENDED FOR NEW DESIGNS	Surge Stopper with Ideal Diode
Ideal Diodes and PowerPath Controllers 2
LTC4359	RECOMMENDED FOR NEW DESIGNS	Ideal Diode Controller with Reverse Input Protection
LTC2955	RECOMMENDED FOR NEW DESIGNS	Pushbutton On/Off Controller with Automatic Turn-On

Parts	Product Life Cycle	Description
LTC3859AL	PRODUCTION	Triple Output, Buck/Buck/Boost Synchronous Controller with 28μA Burst Mode I_Q

Tools & Simulations

LTspice

Models for the following parts are available in LTspice:

LTC3859
LTC3859AL

LTpowerCAD

Design tools for the following parts are available in LTpowerCAD:

LTC3859AL(BOOST)
LTC3859AL(BUCK)

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

Evaluation Kits

LTC3859A Demo Board | Triple Output, Buck/Buck/Boost, 4.5V ≤ VIN ≤ 36V, VOUT1 = 5V @ 5A, VOUT2 = 8.5V @ 3A, VOUT3 = 10V @ 2A

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Product Details

Demonstration circuit DC1425A is a triple output synchronous step-up/dual step-down power supply featuring the LTC3859AIFE. The demo board is has the LTC3859AIFE buck inputs supplied from the boost output. With this boost-then-buck topology, the buck outputs maintain regulation over the entire 4.5V to 36V input range and the application is suitable for automotive or other battery fed applications where low quiescent current is important. The buck controllers provide 5V @ 5A and 8.5V @ 3A and the boost can supply 10V @ 2A when the bucks are drawing their maximim load current.

Resources

DC1425A - Demo Manual
5/3/2012

DC1425A - Design Files
5/5/2010

DC1425A - Schematic
5/5/2010

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