SC8821 datasheet(4/9 Pages) SILAN

4 / 9 page

SC8821

HANGZHOU MICROELECTRONICS CO.,LTD

REV:1.2

2009.05.05

Http: //www.silan.com.cn

Page 4 of 10

Release of Overcharge State

There are two ways to return to normal state from overcharge state

• If the battery is self discharging and VDD<VOCR occurs, it returns to normal state.

• Remove the charger and connected to a load. If VOCR<VDD<VOCU and VCSI>VOI1 occurs, it returns to

normal state.

Overdischarge Detection

When enters discharging state from normal state, the battery voltage can be detected from VDD. When the load

is connected between VBAT+ and VBAT-, if VDD is smaller than VODL and the delay time is over TOD; then the

battery voltage enters overdischarge state, VBAT- current is 0 and stop discharging. At the same time, CSI is

pulled to VDD with internal resistor RCSID. If VCSI>VOI2, the protection IC enters into Power-down mode. (Its

current consumption is lower than 0.3

μA).

Release of Power-Down State

When the battery remains in Power-down state, if a charger is connected between VBAT+ and VBAT-. And

VCH<VCSI<VOI2 & VDD<VODR occur, it releases Power-down state. If VDD>VODR occurs, it returns to normal

state.

Charger Detection

If a charger is connected between VBAT+ and VBAT- while the battery remains in Power-down state, and the

voltages become VCSI<VCH and VDD>VODL, it returns to normal state.

Abnormal Charging Detection

If a charger is connected between VBAT+ and VBAT- in normal state, if VCSI<VCH, and the delay time is over

TOC , then VBAT- current is 0 and stop charging.

Over Current/Short Current Detection

In normal state, the load is connected between VBAT+ and VBAT- ,when the discharging current is too big and

the CSI voltage is larger than VOIX (VIO1 or VIO2),and the delay time is over TOIX (TIO1 or TIO2), it means the

over current/short current state occurs. CSI is pulled to VSS with an internal resistor RCSIS, VBAT- current is 0

and VBAT- voltage is pulled to VDD because of the load.

Release of Over Current/Short Current State

While the protection IC remains in Over Current/Short Current state, and the load is removed or the impedance

between VBAT+ and VBAT- is larger than 500K

Ω and VCSI<VOI1, it is back to normal state.

0V charging forbidden

When a charger is connected between VBAT+ and VBAT- and VDD<VINH, the current at VBAT- is 0 and battery

can not be charged..

0V charging allowed

When a charger with the voltage over VCHA is connected between VBAT+ and VBAT, the battery can be

charged.

Note: when a battery is connected to a protection IC at first time, the IC may not enter the normal state, it can

not discharge. If happens, please connect charger between VBAT+ and VBAT- to enter the normal state.

SC8821 데이터시트(PDF) 4 Page - Silan Microelectronics Joint-stock

SC8821 데이터시트(HTML) 4 Page - Silan Microelectronics Joint-stock

Html Pages

1 2 3 4 5 6 7 8 9

데이터시트 다운로드

링크 URL