ACE4054

Fully integrated constant current/constant voltage

Li-ion battery charger

VER 1.4

3

Pin Description

CHRG (Pin 1):Open-Drain Charge Status Output. The CHRG pin outputs low when the battery is

charging.Upon the completion of the charge cycle, a weak pull-down current to the pin

indicates an“AC present” condition. When the ACE4054 detects an under voltage lockout

condition, CHRG is forced high impedance.

GAN (Pin 2):Ground.

BAT (Pin 3):Charge Current Output. This pin provides charge current to the battery and regulates the final

float voltage to 4.2V which is set by an internal precision resistor divider.

VCC (Pi

n 4):Positive Input Supply. Needs to be bypassed with at least a 1μF capacitor. When input

voltage drops to within 30mV of the BAT pin voltage, the ACE4054 switches to shutdown

mode.

PROG (Pin 5):Program, Monitor the charge current and Shutdown. This pin set to 1V in constant-current

mode. The charge current is programmed by connecting a 1% resistor, RPROG, to GND

pin. The charge current can be calculated using the following formula:

The PROG pin can also be used to switch the charger to shutdown mode by disconnecting the program

resistor from ground. This results in a 3μA current to pull the PROG pin to a high level shutdown threshold

voltage, thus stop the charging and reduce the supply current to 25μA. This pin is also clamped to

approximately 2.4V. A higher voltage beyond this value will draw currents as high as 1.5mA. Device

normal operation can be resumed by reconnecting the RPROG resistor to ground.

Ordering information

ACE4054 XX

+

H

Pb - free

BN : SOT-23-5

IM : ESOP-8

Halogen - free