UB242(2009) 데이터 시트보기 (PDF) - Unisonic Technologies

부품명

상세내역

제조사

UB242
(Rev.:2009)

LITHIUM-ION/POLYMER BATTERY PROTECTION IC

Unisonic Technologies 

UB242

Preliminary

CMOS IC

„ DESCRIPTION OF OPERATION

1. Normal Condition

The voltage of the battery connected between VDD and VSS can be monitored by the UB242.The voltage

difference between CSI and VSS can sense the charge and discharge scheme. Under this condition: VODL<VDD<VOCU

and VCH<VCSI<VOI1, UB242 will turn on the M2 (charging) and M1 (discharging) control MOSFETs.

2. Overcharge Condition

M2 will be turned off under this condition: the battery voltage becomes higher than the overcharge detection

voltage (VOCU) during normal charging condition through a delay time longer than TOC (the overcharge detection delay

time).

3. Release of Overcharge Condition

Two ways to return to normal condition from overcharge condition:

(1.) Under the condition: the battery is self discharging, and if VDD<VOCR and VOI1>VCSI>VCH occurs, UB242

will be back to normal condition.

(2.) Connect UB242 to a load and remove the charger.

4. Overdischarge Condition

M1 will be turned off to stop discharging when the battery voltage falls below the overdischarge detection voltage

(VODL) during discharging condition and through a delay time longer than TOD (the overdischarge detection delay

time).And then CSI will be pulled up to VDD through an internal resistance.When VCSI>VOI2,the chip will enter into

power-down mode. In this mode, the current consumption is lower than 0.1μA.

5. Release of Power-down mode

There are two ways back to normal condition:

(1.) If VCSI<VCH (Charger detection), when VDD>VODL

(2.) If VCH<VCSI<VOI2, the condition VDD>VODR

6. Charger Detection

Charger detection is this action: while connecting to a charger after entering into power-down mode, then if

VDD<VCH, M1 will be turned on when VDD>VODL, and then the system will be back to normal condition as described in

1) of previous section.

7. Abnormal Charge Current Condition

The abnormal charge current condition is when a charger is connected to the battery system in normal condition,

then if VDD<VOCU and VCSI<VCH occurs through a delay time than TOC (delay time of overcharge detection), and in this

condition M2 will be turned off to stop this charging status.

8. Over Current/Short Circuit Condition

The over current (or short circuit) condition is when the current is too large during discharging under normal

condition as a result of the voltage detected by CSI is greater than VOI1 (or VOI2) through a delay time TOI1 (TOI2).In this

over current (or short circuit) condition: M1 will be turned off and CSI will be pulled down to VSS through an internal

resistance.

9. Release of Over Current/Short Circuit Condition

If the load is removed or the impedance between VBAT+ and VBAT- is larger than 500kΩ as well as VCSI<VOI1, M1

will be turned on and the back to normal condition.

10. DS Pin

The delay time of the overcharge and overdischarge can be reduced to within 50ms by forcing DS to VDD. A

1.6MΩ pull down resistor should be connected between DS pin and VSS internally. In the actual application DS pin

should be left open or connected to VSS.

UNISONIC TECHNOLOGIES CO., LTD

www.unisonic.com.tw

6 of 13

QW-R502-307.c

Share Link: