SC451XX-01 데이터 시트보기 (PDF) - Unspecified

부품명

상세내역

제조사

SC451XX-01

LI-ION BATTERY PROTECTOR

Unspecified 

Silan

Semiconductors

SC451XX

FUNCTIONAL DESCRIPTION

• VD1/OVER-CHARGE DETECTOR

The VD1 monitors VDD pin voltage. When the VDD voltage crosses over-charge detector threshold VDET1

from a low value to a value higher than the VDET1, the VD1 can sense over-charging and an external charge

control Nch-MOS-FET turns to “off” with COUT pin being at “L”.

An output delay time for over-charges detection can be set by an external capacitor C3 connecting the VSS

pin and Ct pin. The external capacitor can make a delay time form a moment detecting over-charge to a time

output a signal which enables charge control Nch-MOS-FET for turning to “off”. Though the VDD voltage would be

going up to a higher level than VDET1 if it is within a time period of the output delay time, VD1 would not output a

signal for turning “off” of charge control Nch-MOS-FET. The output delay time can be calculated as below:

tVDET1 =

C3 × (VDD − 0.7)

0.48 ×10−6

A level shifter incorporated in a buffer driver for the COUT pin makes the “L” of COUT pin to the V-pin voltage

and the “H” of COUT pin is set to VDD voltage with CMOS buffer.

• RESET CONDITIONS FROM OVERCHARGING OF SC451XX-01

There can be two cases to reset the VD1 making the COUT pin level to “H” again after detecting over-charge.

Resetting the VD1 makes the charging system ready for resumption of charging process.

The first case is in such condition that a time when the VDD voltage is coming down to a level lower than

“VDET1-VHYS1”. While in the second case, disconnecting a charger from the battery pack can make the VD1

resetting when the VDD level is within hysteresis width (VDET1-VHYS1≤VDD≤VDET1).

After detecting over-charge with the VDD voltage of higher than VDET1, connecting system load to the

battery pack makes load current allowable through parasitic diode of external charge control Nch-MOS-FET. The

COUT level would be “H” when the VDD level is coming down to a level below the VDET1 by continuous drawing of

load current.

• RESET CONDITIONS FROM OVERCHARGING OF SC451XX-02

After detecting over-charge, the VD1 would not be release and COUT level would not switch to “H” again with

the exception that a cell voltage reaches to a lower value than “VDET1-VHYS1” by self discharge of cell or else.

After detecting over-charge, when the VDD level stays at a value higher than “VDET1-VHYS1”, to connect battery

pack to a system load makes battery pack being disable at for charging or discharging because of excess current

detector operated being DOUT ”L”.

HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD

Rev: 1.0 2000.12.31

4

Share Link: