Standalone 750mA Li-Ion Battery Charger in 2 x 2 DFN

The LTC4065 is a complete constant-current/constant-voltage linear charger for single-cell lithium-ion batteries. Its 2mm × 2mm DFN package and low external component count make the LTC4065 especially well-suited for portable applications. Furthermore, LTC4065 is specifically designed to work within USB power specifications.

The CHRG pin indicates when charge current has dropped to ten percent of its programmed value (C/10). An internal timer terminates charging according to battery manufacturer specifications.

No external sense resistor or blocking diode is required due to the internal MOSFET architecture. Thermal feedback regulates charge current to limit the die temperature during high power operation or high ambient temperature conditions.

When the input supply (wall adapter or USB supply) is removed, the LTC4065 automatically enters a low current state, dropping battery drain current to less than 1µA. With power applied, LTC4065 can be put into shutdown mode, reducing the supply current to less than 20µA.

The full-featured LTC4065 also includes automatic recharge, low-battery charge conditioning (trickle charging), soft-start (to limit inrush current) and an open-drain status pin to indicate the presence of an adequate input voltage (LTC4065A only).

The LTC4065 is available in a tiny 6-lead, low profile (0.75mm) 2mm × 2mm DFN package.

Float Voltage (V)

Charge Current Range

Pin 5 Is EN or ACPR?

Trickle Charge?

LTC4065

4.2V

40mA to 750mA

EN

Yes

LTC4065A

4.2V

40mA to 750mA

ACPR

Yes

LTC4065-4.4

4.2V

40mA to 750mA

EN

Yes

LTC4065L

4.2V

8mA to 250mA

EN

Yes

LTC4065LX

4.2V

8mA to 250mA

EN

No

LTC4065L-4.1

4.1V

8mA to 250mA

EN

Yes

Applications

* Wireless PDAs

* Cellular Phones

* Portable Electronics

* Complete Linear Charger in 2mm × 2mm DFN Package

* C/10 Charge Current Detection Output Timer Termination

* Charge Current Programmable up to 750mA with 5% Accuracy

* No External MOSFET, Sense Resistor or Blocking Diode Required

* Preset 4.2V Float Voltage with 0.6% Accuracy

* Constant-Current/Constant-Voltage Operation with