LTC4064

1

sn4064 4064fs

APPLICATIO S

FEATURES

TYPICAL APPLICATIO

DESCRIPTIO

Prolongs 4.2V Li-Ion Battery Lifetime

without Risk of Overheating*

Required

Monolithic Linear Charger

for Back-Up Li-Ion Batteries

The LTC4064 is a standalone linear charger optimized for

prolonging the life of 1-cell Li-ion batteries in battery back-

up applications. By charging to a float voltage of 4V

instead of 4.2V or 4.1V, the LTC4064 decelerates the aging

process and capacity degradation when the battery is

unused for long periods of time but must be in a ready

state.

An external capacitor programs a safety timer to terminate

the charge cycle while the charge current is set externally

with a single resistor. When the input supply is removed,

the LTC4064 automatically enters a low current sleep

mode, dropping the battery drain current to less than 3µA.

Additional safety features designed to maximize battery

lifetime and reliability include NTC temperature sensing

and low battery charge conditioning (trickle charging).

The IC contains an on-chip power MOSFET and eliminates

the need for an external sense resistor and blocking diode.

The LTC4064 also includes C/10 detection circuitry, AC

present logic, and fault detection circuitry.

, LTC and LT are registered trademarks of Linear Technology Corporation.

BAT

PROG

TIMER

NTC

GND

1.5k

1%

4.7µF

0.1µF

4064TA01

SHDN

1-CELL

Li-Ion

BATTERY*

*AN OUTPUT CAPACITOR MAY BE REQUIRED

DEPENDING ON BATTERY LEAD LENGTH

8

2

9

7

5, 11

6

4

LTC4064

Standalone Back-Up Li-Ion Battery Charger

*US Patent No. 6522118