LTC4040

RECOMMENDED FOR NEW DESIGNS

LTC4040

2.5A Battery Backup Power Manager

RECOMMENDED FOR NEW DESIGNS

4.5V Backup Application with 4.22V PFI Threshold (Charge Current Setting: 1A, Input Current Limit Setting: 2A) slide

Normal to Backup Mode Transition Waveform slide

4.5V Backup Application with 4.22V PFI Threshold (Charge Current Setting: 1A, Input Current Limit Setting: 2A)

Normal to Backup Mode Transition Waveform

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Part Models 4

1ku List Price Starting From $3.49

Features

Step-Up Backup Supply and Step-Down Battery Charger
6.5A Switches for 2.5A Backup from 3.2V Battery
Input Current Limit Prioritizes Load Over Charge Current
Input Disconnect Switch Isolates Input During Backup
Automatic Seamless Switch-Over to Backup Mode
Input Power Loss Indicator
System Power Loss Indicator
Pin Selectable Battery: Li-Ion (3.95V/4.0V/4.05V/4.1V) or LiFePO₄ (3.45V/3.5V/3.55V/3.6V)
Optional OVP Circuitry Protects Device to >60V
Constant Frequency Operation
Low Profile (0.75mm) 24-Lead 4mm × 5mm QFN Package

Additional Details

The LTC4040 is a complete 3.5V to 5.5V supply rail battery backup system. It contains a high current step-up DC/DC regulator to back up the supply from a single-cell Li-Ion or LiFePO₄ battery. When external power is available, the step-up regulator operates in reverse as a step-down battery charger.

The LTC4040’s adjustable input current limit function reduces charge current to protect the main supply from overload while an external disconnect switch isolates the external supply during backup. When the input supply drops below the adjustable PFI threshold, the 2.5A boost regulator delivers power from the battery to the system output.

An optional input overvoltage protection (OVP) circuit protects the LTC4040 from high voltage damage at the V_IN pin. One logic input selects either the Li-Ion or the LiFePO₄ battery option, and two other logic inputs program the battery charge voltage to one of four levels suitable for backup applications. The LTC4040 is available in a low profile (0.75mm) 24-Lead 4mm × 5mm QFN package.

Applications

Fleet and Asset Tracking
Automotive GPS Data Loggers
Automotive Telematics Systems
Toll Collection Systems
Security Systems
USB Powered Devices

View All Documentation

Ask a Question

Submit your question below and we will return the best answer from ADI’s knowledge database:

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Support

Analog Devices Support Portal is a one-stop shop to answer all your ADI questions.

Visit the ADI Support Page

Ask the ADI community for help.

Ask the EngineerZone Community

FAQs

Sales & Ordering FAQs

Part Models 4

1ku List Price Starting From $3.49

Technical Documents 7

LTC4040: 2.5A Battery Backup Power Manager Data Sheet 08/24/2017

R457 Reliability Data 03/26/2018

DC2118A - Demo Manual 09/03/2015

DC2118B - Demo Manual 01/06/2020

Reverse Voltage Protection for Battery Chargers 06/01/2020

AN-2083: Integrated Power Supply Solution for Vehicle Tracking System 11/04/2020

Got Backup? Maintain Power Continuity 09/01/2018

Reference Materials 3

Power You Can Trust: Achieving Efficient Battery-Powered Solutions 11/07/2023

Industrial Battery Chargers Overview 10/17/2023

Backup Power Solutions 07/13/2017

Design Resources 4

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
LTC4040EUFD#PBF	24-Lead QFN (4mm x 5mm x 0.75mm w/ EP)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC4040EUFD#TRPBF	24-Lead QFN (4mm x 5mm x 0.75mm w/ EP)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC4040IUFD#PBF	24-Lead QFN (4mm x 5mm x 0.75mm w/ EP)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC4040IUFD#TRPBF	24-Lead QFN (4mm x 5mm x 0.75mm w/ EP)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys

LTC4040EUFD#PBF
Pin/Package Drawing
24-Lead QFN (4mm x 5mm x 0.75mm w/ EP)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC4040EUFD#TRPBF
Pin/Package Drawing
24-Lead QFN (4mm x 5mm x 0.75mm w/ EP)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC4040IUFD#PBF
Pin/Package Drawing
24-Lead QFN (4mm x 5mm x 0.75mm w/ EP)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC4040IUFD#TRPBF
Pin/Package Drawing
24-Lead QFN (4mm x 5mm x 0.75mm w/ EP)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

Companion Parts 2

Parts	Product Life Cycle	Description
Low Voltage Hot Swap Controllers1
LTC4231	RECOMMENDED FOR NEW DESIGNS	Micropower Hot Swap Controller
PowerPath, Ideal Diodes, and Load Switches1
LTC4417	RECOMMENDED FOR NEW DESIGNS	Prioritized PowerPath^™ Controller

Alternative Parts 1

Parts	Product Life Cycle	Description
LTC4110	PRODUCTION	Battery Backup System Manager

DC2118B

LTC4040 Demo Board | 5VIN, 2A Single Cell Li-ion/LiFePO4 Buck Battery Charger with 2.5A Boost Backup Power Manager

LTC4040 Demo Board | 5VIN, 2A Single Cell Li-ion/LiFePO4 Buck Battery Charger with 2.5A Boost Backup Power Manager

Download

DC2118B

LTC4040 Demo Board | 5VIN, 2A Single Cell Li-ion/LiFePO4 Buck Battery Charger with 2.5A Boost Backup Power Manager

Buy Now View Details

Product Detail

Demonstration circuit 2118B is a combination step-down battery charger and step-up battery backup regulator using the LTC4040 monolithic system power manager. The DC2118B has an input voltage range from 4.8V to 5.5V with overvoltage protection (OVP) to 40V, as limited by the external MOSFET. The input current is monitored to prioritize the load up to the 2.5A threshold before charge current is reduced.

Battery Charging

As initially configured, DC2118B is programmed for 2A charge current limit when in charge mode. The charge voltage is jumper-selectable in 8 discrete steps from 3.45V to 3.6V for LiFePO₄ chemistry or 3.95V to 4.1V for Li-ion chemistry, according to the F2/F1/F0 programming input settings.

The charge current limit is adjustable via the PROG pin resistor. End-of-charge status is triggered by current falling below C/8 and indicated by the CHRG LED. The optional NTC input provides temperature fault detection and status indicated by the FAULT LED. Charging can be enabled/disabled with the ENCHG jumper.

Battery Backup

Following an input power failure, the circuit automatically shifts to battery backup boost mode to regulate the VSYS output rail. The backup mode system output voltage is initially programmed for 5V. The input power failure status is indicated by the PFO LED.

If VSYS ever falls below the programmed reset threshold voltage, the RST LED will change states to indicate the need to reset the system and recharge the battery. Backup regulation can be enabled/disabled with the ENBST jumper.

For convenience, all LEDs can be disabled with the LED jumper to reduce the quiescent current of the system.

Resources

PDF

DC2118B - Demo Manual

612.3 K

PDF

DC2118B - Schematic

73.97 K

ZIP

DC2118B - Design Files

3.91 M

DC2118A

OBSOLETE: LTC4040 Demo Board | 5VIN, 2A Single Cell Li-ion/LiFePO4 Buck Battery Charger with 2.5A Boost Backup Power Manager

OBSOLETE: LTC4040 Demo Board | 5VIN, 2A Single Cell Li-ion/LiFePO4 Buck Battery Charger with 2.5A Boost Backup Power Manager

Download

DC2118A

OBSOLETE: LTC4040 Demo Board | 5VIN, 2A Single Cell Li-ion/LiFePO4 Buck Battery Charger with 2.5A Boost Backup Power Manager

Buy Now View Details

Product Detail

This evaluation board is obsolete and no longer recommended.

Demonstration circuit 2118A is a combination step-down battery charger and step-up battery backup regulator using the LTC4040 monolithic system power manager. The DC2118A has an input voltage range from 4.8V to 5.5V with overvoltage protection (OVP) to 40V, as limited by the external MOSFET. The input current is monitored to prioritize the load up to the 2.5A threshold before charge current is reduced.

Resources

ZIP

DC2118A - Design Files

2.00M

PDF

DC2118A - Demo Manual

348.00K

PDF

DC2118A - Schematic

35.00K