UB291

Preliminary

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

9 of 9

www.unisonic.com.tw

QW-R128-002.b



TYPICAL APPLICATION CIRCUIT

M1

M2

R1=100~470Ω

C1=0.1µF

R2=2.2kΩ

DO

CO

Battery

EB+

EB-

UTC UB291

DS

Notes: 1. R1 and C1 stabilize a supply voltage ripple. However, the detection voltage rises by the current of

penetration in IC of the voltage detection when R1 is enlarged, and the value of R1 is adjusted to 1kohm

or less. Moreover, adjust the value of C1 to 0.01uF or more to do the stability operation, please.

2. R1 and R2 resistors are current limit resistance if a charger is connected reversibly or a high voltage

charger that exceeds the absolute maximum rating is connected. R1 and R2 may cause a power

consumption will be over rating of power dissipation, therefore the ’R1+R2’ should be more than 1kohm.

Moreover, if R2 is too enlarged, the charger connection release cannot be occasionally done after the

overdischarge is detected, so adjust the value of R2 to 10kohm or less, please.

3. C2 and C3 capacitors have effect that the system stability about voltage ripple or imported noise. After

check characteristics, decide that these capacitors should be inserted or not, where should be inserted,

and capacitance value, please.

UTC assumes no responsibility for equipment failures that result from using products at values that

exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or

other parameters) listed in products specifications of any and all UTC products described or contained

herein. UTC products are not designed for use in life support appliances, devices or systems where

malfunction of these products can be reasonably expected to result in personal injury. Reproduction in

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presented in this document does not form part of any quotation or contract, is believed to be accurate

and reliable and may be changed without notice.