Research On Key Technologies Of Integrated Power NMOSFET For Lithium Battery Protection Chip

In this paper,an important technical module of traditional lithium battery protection chip is researched and optimized.Based on tsmc 0.18um process,the core module is designed.In the ultra-low power consumption of the concept,the overall chip circuit design and implementation.For overcharge protection,overcharge protection release,overdischarge protection and over discharge protection release function,only a single single-tube comparator to achieve four voltage threshold protection of low-power modules,the use of hysteresis comparator characteristics to complete a group of double The comparator output of the threshold is inverted,and the sampling voltage is used to control the sampling voltage to distinguish the dual threshold of the other group,thus completing the four-threshold flip characteristic of the single comparator,using the bandgap reference principle to zero the temperature of the comparator threshold To adjust the resistance,the highest temperature drift after the correction of 29.08ppm,to ensure the accuracy of the threshold.To further optimize the loss of power consumption,two-phase non-overlapping clocks are added to the circuit.The two phases of the clock are controlled by disconnecting and connecting the core structure of the two comparators so that the current and voltage comparators do not work at With the same phase,so that the overall average power consumption of the two sets of comparators is reduced to less than 5uA.The two-phase non-overlapping clock source clock is provided by the oscillator.The oscillator design is based on a three-stage ring oscillator designed for ring oscillators that produce a clock frequency of about 5.46 MHz,providing a stable clock pulse for the circuit.The designed oscillator circuit not only provides input for two-phase unwanted clocks,but also provides input clock for the delay module.The design idea of the delay circuit is basically accomplished by a plurality of edge D flip-flops which perform different delays on the output signals of the respective comparators in order to prevent the comparator from accidentally inverting by the noise of the power supply Related protection circuit misuse.After the delay,the noise in the power supply can be eliminated.In addition,as a lithium battery protection chip in another important module,as the switch tube power NMOSFET on-resistance optimization program,and in order to ensure that the power tube can turn on the characteristics of high current,select a special waffle-type power tube Layout layout design area 958.7?m*409.5?m on-resistance value of 22m?,contrast to complete the power tube on-resistance optimization,and then complete the reduction of the layout area optimization.