Lithium-ion battery protection circuit, including over-charge protection, over-current / short circuit protection and over-discharge protection, the requirements have been high-precision charge protection, the protection of IC low-power, high-voltage and zero-volt rechargeable, and other characteristics. This paper describes the three principles of the protection circuit, the new functions and features request
In recent years, the more and more products adoption lithium batteries such as PDA, numerical camera, cellular phone, the portable sound 讯 equipments and the blue bud equipments etc. is the main power supply.The lithium battery has the physical volume small, the energy density is high, has no memory effect, circularly the high and high electric voltage battery of life span is similar to from turn on electricity the rate low etc. advantage, with the 镍镉 , the 镍 hydrogen battery not too, the safety that lithium battery must consider to refresh, turn on electricity, in order to prevent the characteristic is inferior to turn.Aim at the lithium battery of turn on electricity, conduct electricity to flow over the 充 and excessively and the short-circuit proof is very important, so usually would in battery wrap the design protects the circuit to protect the lithium battery in order to.
Because the lithium ion battery energy density is high, so hard insure the safety of the battery.At refresh the appearance excessively under, the battery temperature rising after the energy press rising excess, hence the electrolyte resolves but produces the air, the danger that stem from the 燃 or break because of inside;Whereas, at turn on electricity the appearance excessively under, the electrolyte causes the battery characteristic and durables inferior to turn because of the decomposition, as a result lower and can refresh the number of times.
The protection electric circuit of the lithium ion battery be to insure thus of refresh and turn on electricity the appearance excessively of safety, and prevent°from the characteristic inferior turn.The protection electric circuit of the lithium ion battery is from the protection IC and two power MOSFETs composing, among them protect the IC surveillance battery electric voltage, cut over while being to have the excessiveness to refresh and turn on electricity the appearance to protect the battery outside the power MOSFET that hang, the protection IC function have the excessiveness to refresh the protection and turn on electricity protection and conduct electricity to flow excessively/ short-circuit proof.
