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DC2118A: LTC4040 Battery Charger and Backup Power Manager Demo Manual

Demonstration circuit 2118A features the LTC4040, a 2.5A buck battery charger and boost backup power manager for Li-ion and LiFePO4 chemistry batteries.

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Overview

The DC2118A is a demonstration circuit for the LTC4040, a monolithic system power manager that combines a step-down battery charger with a step-up battery backup regulator. It supports an input voltage range of 4.8V to 5.5V with overvoltage protection up to 40V. The circuit provides a 2A default charge current and features jumper-selectable charge voltages for Li-ion and LiFePO4 chemistries. Upon input power failure, it automatically switches to a backup boost mode to regulate the 5V system output. Key features include input current monitoring, NTC temperature fault detection, and status LED indicators for charge, fault, and power failure conditions.

Use Cases

  • Battery backup systems
  • Uninterruptible power supplies
  • Portable industrial devices
  • Li-ion and LiFePO4 battery management
  • System power failure protection

Topics

LTC4040
battery charger
backup power manager
Li-ion
LiFePO4
boost regulator
buck charger
DC2118A
power management IC
overvoltage protection

Referenced Parts

8834

Keystone Electronics

STAND-OFF, NYLON

2SN-BK-G

Samtec

3 7 XJP1-XJP7 SHUNT, 2mm SAMTEC 2SN-BK-G

TMM-103-02-L-S

Samtec

2 7 JP1-JP7 3 PIN JUMPER, 2mm SAMTEC TMM-103-02-L-S

2mm

Samtec

2 7 JP1-JP7 3 PIN JUMPER, 2mm SAMTEC TMM-103-02-L-S

2mm

Samtec

3 7 XJP1-XJP7 SHUNT, 2mm SAMTEC 2SN-BK-G

20-V

Vishay

7 1 Q2 XSTR, MOSFET N-CHANNEL, 20-V VISHAY, SiS424DN-T1-GE3

40-V

Vishay

7 1 Q1 XSTR, MOSFET N-CHANNEL, 40-V VISHAY, SiS488DN-T1-GE3