Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [ripple-current]

Small unwanted residual periodic variation of the direct current (dc) output

The most common meaning of ripple in electrical science is the small unwanted residual periodic variation of the direct current (dc) output of a power supply which has been derived from an alternating current (ac) source. This ripple is due to incomplete suppression of the alternating waveform within the power supply.

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Are all linear regulators bad at filtering input ripple? (or really as bad as Dave suggests)?

Background In EEVBlog #1116, Dave discusses a method to remove power supply ripple, and goes on to show (see 5:17 to 6:15) that you cannot count on linear regulators to remove your input ripple. He gave a concrete example in the lab: at 10 kHz input…
anrieff
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Ground plane directly underneath physically large 100 µH inductor?

I plan to use a physically large ferrite core inductor (Murata part "1410478C", 100 µH at 1 kHz) in a 12 V, 7 A DC filter circuit. It will be mounted on topside of a four-layer PCB (from top down: top routing, split GND plane, split PWR plane, and…
user98663
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Capacitor Ripple Current - Frequency coefficient

I am designing a motor controller with a 11A max start load and 3A max continuous load. Looking for capacitors I found in this datasheet a "Frequency coefficient for ripple current", what is that and how am I supposed to use this in calculations.
mFeinstein
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Should I measure ripple current on a replacement capacitor of lowered ESR?

I've changed an 820 μF capacitor on the output of a 1.05 V linear regulator which feeds the PCH (Intel's Platform Controller Hub), or "southbridge", on a PC motherboard.    It's working fine but I want to confirm that I'm not stressing the new…
Kevin
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Calculate peak input current of switch mode power supply

I have the following problem. MY ATTEMPT The switch-mode power supply looks like it's a boost converter. I found that the DC-transfer functions for the boost converter to be: \$\frac{V_C}{V_{in}}=\frac{1}{1-d} \: \: \$ and…
Carl
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Boost LED driver output spikes

I designed a boost LED driver based on TPS92691. It drives 56V 5A COB LED from 22-50V input. It works ok. Oscilloscope shows small spikes on input (100mV), but large spikes on output (3V). The spikes are from switching (400 kHz). I started with…
Roman Simonyan
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What might this term (\$N_C\$) be, calculating ripple current for a buck converter output capacitor?

I'm reading through the datasheet for TI's TPS54302 step-down converter, and determining values for support components. There is a calculation to determine ripple current for the output capacitor which is: $$ I_{COUT(RMS)} = \frac{1}{\sqrt12} \times…
JYelton
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Measuring Output Ripple Voltage Problem

This is a followup of my previous question. Boost IC = NCV3063 Vin = 8V Vout = 23V Iout(max) = 250mA - (Load is a constant current circuit which is enabled at 200Hz) Schematic Mentioned the points where I have probed Waveforms (Same waveform, only…
user220456
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Understanding inductor and LED ripple current in LM3409

I am reading the datasheet of the LM3409, specifically section 9 "Application and implementation". My intent is to understand how to calculate the values of the components needed for my specific application. I aim to drive a single LED with a…
feralgeometry
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How to convert Ripple Current spec to ESR?

It used to be that vendors like Digikey gave a cap's ESR value and not ripple current. Nowadays, it seems more report only ripple current and not ESR. What gives with that? So what are we supposed to do with "ripple current" if we want to know ESR? …
rdtsc
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Where can I find a stable AC to DC switching power supply?

I've purchased multiple 3V switching power regulators form Amazon and they all have spikes in the ripple. Here's an O-scope capture: The spikes increase frequency depending on the load. Are these spikes a fact of life or are there better products…
peteey
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Can I substitute a capacitor with the same rated capacity and voltage but a lower inductance and higher rated ripple current for a mobo repair?

I have an early to mid 2000's motherboard that I am trying to restore. It looks to be mostly in good condition but a blown radial electrolytic capacitor might be causing trouble. From the placement of the capacitor on the board between the ATX 20…
Zeno of Elea
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Coupled inductors for multi-output buck

I see coupled inductors are generally used in multi-phase design to take advantage of current ripple cancellation. What is really the advantage of coupled inductor in multi-output buck or multi-output forward converter? Does it help in cross…
Divya K.S
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Capacitor specifications, ripple current and life

What does the "Ripple current" and the "Life (in Hours)" in electrolytic capacitors specifications mean? My intuition says it's the highest current it can handle and it can operate for that hours (when it works under that ripple current) before it…
MrBit
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SMPS Input/Output ripple current and ripple voltage

I found a presentation regarding SMPS and found this slide. I am not totally able to grasp the concept of the input and output ripple current. In the above image I have the following questions : I thought input capacitors are used only for…
user220456
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