Datasheet

PORorRECHARGE

Enable 125 mA Charge,

Start 0.5stimer

VFB > V

RECH

BatteryPresent,

BeginCharge

0.5stimer

expired

Yes

Disable 125mA

Charge

Apply 8mA discharge

current, start 1stimer

VFB < V

LOWV

BatteryPresent,

BeginCharge

1stimer

expired

Yes

Disable 8mA

dischargecurrent

Thebatterydetectionroutinerunson

powerup, orifVFBfallsbelowVRECH

duetoremovingabatteryor

dischargingabattery

Battery Absent

bq24620

www.ti.com

SLUS893A –MARCH 2010– REVISED OCTOBER 2011

BATTERY DETECTION

For applications with removable battery packs, the bq24620 provides a battery-absent detection scheme to

reliably detect insertion or removal of battery packs. CE must be HIGH to enable battery detection function.

Figure 15. Battery Detection Flowchart

Once the device has powered up, an 8-mA discharge current is applied to the SRN terminal. If the battery

voltage falls below the LOWV threshold within 1 second, the discharge source is turned off, and the charger is

turned on at low charge current (125 mA). If the battery voltage rises above the recharge threshold within 500

ms, no battery is present and the cycle restarts. If either the 500-ms or 1-second timer times out before the

respective thresholds are hit, a battery is detected and a charge cycle is initiated.

Product Folder Link(s): bq24620