ETA4056

www.etasolution.com

5

Empower, Transcend, Achieve!

FUNCTION BLOCK DIAGRAM\

1

8

TA

TTEMP

TTEMP

Schmitt

CA

MA

VA

120

TDIE

80%VIN

45%VIN

NTC

EN

C1

REF

1.17V

C2

C3

2

ISET

6

7

STDBY

STAT

3

GND

5

BAT

4

VIN

SHDN

RISET

2.9V

BAT

1μA

FUNCTIONAL DECRIPTIONS

The ETA4056 is a single cell, fully integrated constant current (CC)/constant voltage (CV) Li-ion battery charger. It can

deliver up to 1200mA of charge current with a final float voltage accuracy of 1%. The ETA4056 has a build-in thermal

regulation circuitry that ensures its safe operation. No blocking diode or external current sense resistor is required;

hence reduce the external components for a basic charger circuit to two. The ETA4056 is also capable of operating

from a USB power source.

Normal Charge Cycle

The ETA4056 initiates a charge cycle once the voltage at the VIN pin rises above the UVLO threshold level. A 1%

precision resistor needs to be connected from the ISET pin to ground. If the voltage at the BAT pin is less than 2.9V,

the charger enters trickle charge mode. In this mode, the charge current is reduced to nearly 1/10 the programmed

value until the battery voltage is raised to a safe level for full current charging.

The charger switches to constant-current mode as the BAT pin voltage rises above 2.9V, the charge current is thus