ACE4703

Fully 5A, 3cell Standalone Li-ion Battery Charger

VER 1.2

8

The TEMP pin’s pull up current is about 50uA, so the NTC thermistor’s resistance should be 10kΩ at

25℃

, about 3.5kΩ at hot temperature threshold, and about 32kΩ at cold temperature threshold. The NTC

thermistor such as TH11-

3H103F, MF52(10 kΩ), QWX-103 and NCP18XH103F03RB can work well with

ACE4703. The above mentioned part numbers are for reference only, the users can select the right NTC

thermistor part number based on their requirements.

If battery temperature monitoring function is not needed, just connect a 10KΩ resistor from TEMP pin to

GND.

Status Indication

The ACE4703 has 2 open-drain status outputs: CHRG and DONE. CHRG is pulled low when the

charger is in charging status, otherwise CHRG becomes high impedance. DONE is pulled low if the

charger is in charge termination status, otherwise DONE becomes high impedance.

When the battery is not present, the charger charges the output capacitor to the regulation voltage quickly,

then the BAT pin’s voltage decays slowly to recharge threshold because of low leakage current at BAT pin,

which results in a ripple waveform at BAT pin, in the meantime, CHRG pin outputs a pulse to indicate that

the battery’s absence. The pulse’s frequency is around 10Hz when a 10uF output capacitor is used.

The open drain status output that is not used should be tied to ground.

The table 1 lists the two indicator status and its corresponding charging status. It is supposed that red

LED is connected to CHRG pin and green LED is connected to DONE pin.

CHRG Pin

DONE pin

State Description

Low (The red LED on)

High Impedance (the green

LED off)

Charging

High Impedance (the red

LED off)

Low (the green LED on)

Charge termination

Pulse signal

Pulse signal

Battery not connected

High Impedance (the red

LED off)

High Impedance (the green

LED off)

There are three possible state:

 The voltage at the VCC pin below the

UVLO level

 The voltage at the VCC pin below V

BAT

 Abnormal battery

’s temp

Table 1 Indication Status