ACE4054C

500mA/1.5A Standalone Linear Li-Ion Battery Charge

VER 1.2

9

During charging, the transient response of the circuit can cause the PROG pin to fall below 100mV

temporarily before the battery is fully charged, thus can cause a premature termination of the charge

cycle. A 1ms filter time (tTERM) on the termination comparator can prevent this from happening. Once the

average charge current drops below 1/10th the programmed value, the ACE4054C terminates the charge

cycle and ceases to provide any current through the BAT pin. In this state, all loads on the BAT pin must

be supplied by the battery.

The ACE4054C constantly monitors the BAT pin voltage in standby mode and resume another charge

cycle if this voltage drops below the recharge threshold (VRECHRG). User can also manually restart a

charge cycle in standby mode either by removing and then reapplied the input voltage or restart the

charger using the PROG pin. A diagram of typical charge cycle is shown in Figure 1.

Figure 1. Charge Cycle Diagram

Charge Status Indicator (CHRG)

There are two different states of the charge status output, namely pull-down and high impedance. The

pull-down state indicates that the ACE4054C is in a charge cycle. When the charge cycle has terminated,

the pin state is then determined by undervoltage lockout conditions. If the difference between VCC and

BAT pin voltage is less than 100mV or insufficient voltage is applied to the VCC pin, High impedance

appears on the charge statues pin.