UB244AL-AD-SM1-R datasheet(5/11 Pages) UTC

5 / 11 page

UB244A

Preliminary

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

5 of 11

www.unisonic.com.tw

QW-R502-857.b



OPERATING

1. Overcharge Detection

CO is turned to “H” (for CMOS output active “H”) when the voltage of one of the batteries exceeds the overcharge

detection voltage (VCU) during charging under normal conditions beyond the overcharge detection delay time (tCU).

This state is called “overcharge.” Attaching FET to the CO pin provides charge control and a second protection. At

that time, the overcharge state is maintained until the voltage of all batteries decreases from the overcharge

detection voltage (VCU) by the equivalent to the overcharge hysteresis voltage (VCD).

2. Delay Circuit

The overcharge detection delay time (tCU) change with an external capacitor (CICT). The delay times are calculated

by the following equations：

Overcharge detection delay time tCU[s] = (15±5 )CICT [μF]



TIMING CHARTS

Battery voltage

V1 Battery

V2 Battery

V3 Battery

V4 Battery

VCD

VCU

CO pin voltage

ICT pin voltage

VSS

VCC

VDET

CMOS output active “H” and

Nch open drain models

VCC

tCU

UB244AL-AD-SM1-R 데이터시트(PDF) 5 Page - Unisonic Technologies