A low frequency supercapacitor circulation technique to improve the efficiency of linear regulators based on LDO ICs

Laplace transform-based theoretical foundations and experimental validation: low-frequency supercapacitor circulation for efficiency improvements in linear regulators

“…Component values were selected to implement the 12V-5V regulator indicated in [8,10] Table 2. This MATLAB evaluations were based on the equation sets [27] indicates the actual supercapacitor model is more complex.…”

“…Single-cell devices are DC rated from about 2.3V to 5.5V, while supercapacitor modules are available with DC voltage ratings beyond 100V. With the availability of very thin profile supercapacitors from manufacturers such as Cap-XX (Australia) [7] with the capacitance values up to several farads and very low equivalent series resistance (ESR) values, a new approach to enhancing the end-to-end efficiency of linear regulators based on low dropout regulator ICs has been developed [8][9][10][11][12][13][14]. The technique is easily applicable to standard cases such as 12V-5V, 5V-3.3V and 5V-1.5V which are common in processor-based electronic systems [15].…”

“…The technique can be easily adapted to other practical applications such as V p <2V in(min) and V p >3V in(min) configurations, as far as the usability of a linear regulator at the output end is broadly applicable [8,10]. If the input voltage is lower than the output, classical switched-capacitor configurations will be required.…”

“…If the input voltage is lower than the output, classical switched-capacitor configurations will be required. A 12V-5V regulator requires only a single supercapacitor, while other combinations such as 5V-3.3V and 5V-1.5V converters require supercapacitor arrays [10]. More details are provided in [8][9][10][11][12][13][14] with various configurations applicable to different input-output voltage combinations.…”

Implementation aspects of a new linear regulator topology based on low frequency supercapacitor circulation

“…To overcome this limitation, LDOs could be coupled with a very low frequency supercapacitor circulation technique [10][11][12][13][14][15][16] to achieve significantly high end-to-end efficiency. A 12V to 5V version (which has a theoretical maximum efficiency of 42%) was initially developed [11] with end to end efficiency in the range of 78% to over 80%.…”