Microprocessor‐conducted noise reduction with switched supercapacitors

Abstract

Microprocessors inject noise into the power distribution network (PDN). The point-of-load (PoL) converters are preferred for microprocessor supplies to reduce the total number of supplies. In addition, PoL helps in reducing voltage drop and power loss, and leverages the PDN impedance requirements by sending power at higher voltage and stepping down at the required location. Switched capacitor converters (SCCs) are replacing inductor-dominated buck converters in PoL applications because of their potential to integrate with microprocessors. A new method to reduce microprocessor-conducted noise by switched supercapacitors built with a 1:1 SCC is proposed. The high-frequency microprocessor noise conducted into the PDN is reduced by the capacitors switching at low frequency. An analogue implementation of the individual switches with low noise coupling through parasitic capacitance and with current limiting is shown. An insertion loss of 40-20 dB in the conducted frequency range (150 kHz-30 MHz) is observed in experiments. The idea can be used as a standalone method or can be incorporated into conventional SCCs with modifications as an additional feature.

Low‐voltage commercial super‐capacitor response to periodic linear‐with‐time current excitation: a case study

“…Hence, the RMS value of the applied Fig. 4 Plot of V nRMS from (12), P n avg from (15), C e f f (in farads) from (19) and m from (22) p n (t) = ∑ n = 1 current excitation with I cc = 1 mA is expected to be…”

“…1. Recalling (12) and using the applied triangle-wave current with fixed I cc at a given frequency ω 0 , an NLSs fitting technique can be applied to minimise the error between the measured v n (t) and that given by (9) in a pre-defined search space of the parameter set (R s , C α , α). The optimum values of these parameters are then considered to be the best model fit.…”

“…Super-capacitors, also known as electric double layer capacitors, are widely used as energy storage devices for numerous applications including solar harvesting for autonomous devices [1], renewable-power systems [2][3][4][5], electric vehicles [6,7], uninterruptible power supplies [8], power regulators [9], wireless sensor nodes [10], biomedical implants [11], and other nonconventional applications [12]. These devices are available with rated capacitances ranging from milli-farads to kilo-farads, placing them between traditional capacitors and electro-chemical batteries in terms of capacity.…”

Commercial supercapacitor parameter estimation from step voltage excitation

“…Supercapacitors are relatively new electrical energy storage devices of great importance for industrial automation applications particularly when renewable energy sources are used . These devices have also found use in many other nonconventional and new applications requiring high rates of energy delivery as an alternative to the sluggish, slow‐responsive batteries …”

“…[1][2][3] These devices have also found use in many other nonconventional and new applications requiring high rates of energy delivery as an alternative to the sluggish, slow-responsive batteries. [4][5][6][7] It is commonly assumed in the academic literature and by the industry that the behavior of supercapacitors can be modeled using standard formulae of ideal capacitors. The ratings given by manufacturers for instance correspond to the direct current (DC) capacitance following standards like the IEC62391 standard which assume that the classical relation i c = Cdv c (t)∕dt apply to these devices.…”