Stacked Structure Design Applied To The Capture Engine

With the increasing popularity of mobile devices such as smart phones,smart watches,and sports bracelets,navigation and positioning components are important sources of power consumption.The capture engine,which is the main energy-consuming unit in the global positioning system receiver,is particularly important for enhancing the power conversion efficiency of the satellite navigation system.At present,most of the capture circuit's power management adopts DC-DC method,which mainly includes linear regulator LDO and switching power supply converter.Due to the low conversion efficiency of LDO,the capture circuit generally adopts a switching power supply structure to enhance conversion efficiency.It can usually reach 80%-90%.However,under the structure of the traditional capture circuit,due to the introduction of large switching capacitor,the use of this method will lead to a larger chip area,and in the best case there will still be about 10% of the power supply losses.In order to further improve the power conversion efficiency and reduce the loss,this paper introduces a voltage stacking technology based on this,and proposes a capture circuit based on a stack architecture to reduce the power loss through the reuse of current between modules and improve the conversion efficiency to over 95%.At the same time,for different working environments,the optimal capacitance design of the stack structure based on different load differential currents at different frequencies is solved,the circuit area is reduced,and the specific design size is given for reference.In the end,the schematic design,layout design and tapeout of the stacked circuit are completed based on SMIC28 nm process.Finally,the performance parameters measured by the N6705 B power analyzer and the oscilloscope DSOX4024 are as follows: The designed capacitance is 200 p F,the floating end output ripple is within 20 m V,and the power conversion efficiency is above 95%.Compared with the traditional capture circuit,when the output ripple at the floating end is basically the same,the area of the power supply section is reduced by more than half,and the overall power conversion efficiency is improved by more than 5%.