US 12,449,450 B2
Inductor current estimation method for DC-DC switching power supply
Shen Xu, Nanjing (CN); Chenxi Yang, Nanjing (CN); Yijie Qian, Nanjing (CN); Yujie Liu, Nanjing (CN); Limin Yu, Nanjing (CN); Weifeng Sun, Nanjing (CN); and Longxing Shi, Nanjing (CN)
Assigned to SOUTHEAST UNIVERSITY, Nanjing (CN)
Appl. No. 18/567,039
Filed by SOUTHEAST UNIVERSITY, Nanjing (CN)
PCT Filed Aug. 3, 2022, PCT No. PCT/CN2022/110105
§ 371(c)(1), (2) Date Dec. 5, 2023,
PCT Pub. No. WO2023/098127, PCT Pub. Date Jun. 8, 2023.
Claims priority of application No. 202111439320.3 (CN), filed on Nov. 30, 2021.
Prior Publication US 2024/0280613 A1, Aug. 22, 2024
Int. Cl. G01R 19/25 (2006.01); G01R 15/04 (2006.01); G01R 19/00 (2006.01); H02M 1/00 (2007.01); H02M 3/157 (2006.01); H02M 3/158 (2006.01)
CPC G01R 19/25 (2013.01) [G01R 15/04 (2013.01); G01R 19/0038 (2013.01); H02M 1/0009 (2021.05); H02M 3/157 (2013.01); H02M 3/158 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An inductor current estimation method for a DC-DC switching power supply, using a voltage sampler, a data converter, a switching signal counter including a comparator, an inductor voltage calculator, and a digital filter, the method comprising:
inputting an input voltage (Vin) and an output voltage (Vo) of a DC-DC switching power supply to the voltage sampler to obtain an input voltage digital quantity (Din[n]) and an output voltage digital quantity (Do[n]), then performing an operation and bit conversion by the data converter to obtain a converted input voltage (Vin[n]) and a converted output voltage (Vo[n]) which have a same number of bits, and outputting the converted input voltage (Vin[n]) and the converted output voltage (Vo[n]) to the inductor voltage calculator, wherein the voltage sampler comprises a sampling circuit and an analog-to-digital converter (ADC), where the sampling circuit samples voltages-obtained by scaling the input voltage (Vin) and the output voltage (Vo) in proportion, by means of voltage dividing resistors, and the voltages are amplified by single-ended to differential amplifiers and then output to the corresponding ADC, such that the input voltage digital quantity (Din[n]) and the output voltage digital quantity (Do[n]) are obtained; and
comparing a node voltage (Vx) with a reference voltage (Vref) by the comparator of the switching signal counter to output actual switching signals, then obtaining a duty cycle (duty[n]) by the switching signal counter counting module and outputting the duty cycle (duty[n]) to the inductor voltage calculator;
calculating an average voltage (ViL[n]) of two terminals of an inductor (L) and a parasitic resistor (RL) by the inductor voltage calculator to reduce a sampling frequency of the voltage sampler; and
performing filtering by the digital filter to obtain an estimated inductor current (IL[n]).