Requirements for maintaining IC performance of lithium batteries

Requirements for maintaining the performance of integrated circuits 1. Overcharge and high maintenance accuracy When the lithium battery is overcharged, in order to prevent the increase in internal pressure caused by the increase in temperature, the charging state should be stopped. The maintenance IC will detect the battery voltage. When overcharge is detected, the overcharge detection power MOSFET will cause it to block and stop charging. At present, it should be noted that the accuracy of the overcharge detection voltage is high. When the battery is charging, the user is most concerned about getting the battery fully charged and taking into account safety issues. Therefore, when the allowable voltage is reached, the charging state should be cut off. In order to combine these two situations, there must be a high-precision detector. The accuracy of the detector is now 25mV, which needs to be further improved. 2. Reduce the power consumption of the maintenance IC. As time goes by, the voltage of the charged lithium battery will gradually decrease until it is lower than the standard value of the specification. At this time, the battery should be charged. If the battery is continuously used without charging, the battery may not be continuously used due to over-discharge. In order to prevent over-discharge, the maintenance IC must test the battery voltage. When the battery voltage is lower than the over-discharge detection voltage, the power MOSFET on the discharge side must be blocked to stop the discharge. But at present, the battery itself still has natural discharge and maintenance IC consumption current, so IC consumption current should be kept to a minimum. 3. Overcurrent/short circuit maintenance requires low detection voltage and high accuracy. If the cause of the short circuit is unknown, stop the discharge immediately. The overcurrent detection uses the Rds(on) of the power MOSFET as the inductive impedance to monitor its voltage drop. If the voltage is higher than the overcurrent detection voltage at this time, the discharge is stopped. In order to make the power MOSFETRds() effective for charging current and discharging current applications, it is necessary to make the impedance value as low as possible. The current impedance is about 20m~30m, and the current voltage can be low. 4. High voltage resistance When the battery pack is connected to the charger, high voltage will appear instantaneously, so the maintenance IC should meet the requirements of high voltage resistance. 5. Low battery power consumption During the maintenance process, the static power consumption current should be reduced by 0.1A. 6.0V charging during storage, some batteries may be reduced to 0V due to excessive time or abnormal reasons, so the need to maintain the IC can also be charged at 0V. Maintaining the development prospects of integrated circuits As mentioned above, future maintenance ICs will further improve the accuracy of detection voltage, reduce the power consumption of maintenance ICs, and improve functions such as preventing misoperation. The high-voltage resistance of the charger terminal is also the focus of research and development. In terms of packaging, sot23-6 has gradually transitioned to SON6 packaging. In the future, there will be CSP packaging and even COB products to meet the current emphasis on lightweight and short requirements. In terms of function, the maintenance IC should not integrate all the functions, and notify a separate maintenance IC according to different lithium battery data, such as only overcharge maintenance or over-release maintenance functions, which can greatly reduce the cost and scale. Functional modules, of course, single crystal is the same goal, such as mobile phone manufacturers are now facing the maintenance of integrated circuits, charging circuits and power management ICs, and other peripheral circuits and logic integrated circuit chips to form a dual chip, but now I want to make open circuit impedance In the fall of power MOSFET, it is integrated with other ICs, even through special skills to single-chip microcomputer, the capital will be too high, I am afraid. Therefore, it takes a certain amount of time to solve the maintenance of IC single crystalization. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Can the spotlight shine on the electrode speed up the charging of the lithium battery?