Questions tagged [esr]

ESR is the "equivalent series resistance" of an electrical component (such as a capacitor or inductor) arising from non-idealities that are always present in the materials used in their construction.

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15
votes
1answer
678 views

Why do some devices use electrolytic capacitors instead of ceramics for small value components?

I've recently run into a number of consumer-grade devices that use 50v, 0.22uF electrolytic capacitors, as well as other similarly rated parts, all below about 10uF. In use, the voltages on them are ...
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2answers
6k views

ESR and ESL, small package vs large (SMD)

I was wondering if someone could explain why larger package capacitors (1210) are supposed to have more ESL and ESR than a smaller - say 0603 package? I would imagine the larger package is still ...
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3answers
4k views

Difference between “|Z|” and “Resistance” in capacitor datasheet?

I'm shopping for capacitors, and I expect good capacitor datasheets to have a graph of |Z| (the magnitude of the capacitor's impedance) as a function of frequency. I was confused when I looked at ...
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4answers
4k views

What is making my DC/DC converter's capacitor to blow up?

I'm having some capacitors blown up and I am not sure what's the cause of this. It is definitely NOT OVERVOLTAGE and NOT in WRONG POLARIZATION. Let me introduce the scenario: I have designed a double ...
10
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1answer
1k views

How does ESR affect cutoff frequency calculations for capacitors?

I'm interested in estimating the cutoff frequency of a capacitor in a simple RC circuit. Since the capacitor and resistor are in series, can I simply add the ESR value to the resistor value? For ...
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3answers
11k views

ESR and parallel capacitors

Just wanting to clarify my understanding of ESR here, because I'm not fully sure if it should be modeled the way I would think to model series resistance. Or if it's more complex than that. Basically ...
7
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3answers
4k views

Why do capacitor datasheets avoid directly giving the ESR value?

Most datasheets give a parameter called "loss tangent" instead of directly giving the ESR value. Why don't they just give a numeric value for it? Why is loss tangent preferred over ESR? Is there ...
6
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2answers
2k views

Why does ceramic capacitor ESR change with frequency?

In most datasheets, I see a typical table which shows that ESR of ceramic capacitor changes with frequency. I understand that impedance of every kind of capacitor must have a minimum due to its ...
6
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3answers
5k views

Modelling Capacitor Leakage

I have a 680uF electrolytic capacitor rated for 25 volts. Yesterday night I was curious as to how much current leaked out of it over time, so I charged it with a generic DC power supply, and measured ...
5
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4answers
907 views

LM2596 and other DC-DC converters why oscillate if the output capacitor ESR value is too low?

I would like to use LM2596 converter. Datasheet says: 'If the selected capacitor's ESR is extremely low, there is a possibility of an unstable feedback loop, resulting in an oscillation at the output.'...
5
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4answers
8k views

ESR meter: Are in-circuit readings accurate?

I recently bought one of these ESR meters, a 'MESR-100': http://www.amazon.com/MESR100-AutoRanging-Circuit-Capacitor-Tester/dp/B00G7OPBP2 It claims to be able to test capacitor ESR with the caps ...
5
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4answers
1k views

Winding my own inductor-resistance

I am building a boost converter 12VDC-24VDC with output current of \$I_{out}=250\:\mathrm{mA}\$ and input current of around \$I_{in}=600\:\mathrm{mA}\$ and need to design an inductor for it. I've ...
5
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3answers
11k views

How is ESR specified on ceramic capacitors?

I'm looking for a capacitor to use as the output capacitor with the LDO regulator SP6205EM5-L-3-3. It says it requires a 2.2 µF capacitor, with an ESR less than 0.5 ohm. I've found the ...
5
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1answer
1k views

Are tantalums good for PIC Vcap?

I understand that ceramics are good at ESR but would like to know if tantalum would suffice for my application. Some 16 bit PICs require a >4.7uf cap (10uf recommended) low ESR cap for their internal ...
4
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1answer
1k views

LDO Minimum ESR on output capacitor

I have been wondering for a while. With cheaper LDO regulators I often see them advertise that you can use a ceramic output capacitor. In the datasheet examples they use them. But then they say things ...
3
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3answers
4k views

Do low-ESR ceramic capacitors in the uF-range exist?

I am designing a power supply for my board and plan to use an isolated, regulated DC-DC converter. This converter from Murata fits the bill, but the datasheet doesn't provide any guidance on input or ...
3
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2answers
343 views

Capacitor Impedance ESR vs Frequency Curve

Yageo's SMT capacitor datasheet lists the ESR vs. Frequency Curve show below: Note that impedance (Z) is listed in units (W). How can this be understood? Why is impedance seemingly not measured in ...
3
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2answers
431 views

LDO regulator (LD39300) output capacitor ESR not so small

I want to use the LDO regulator LD39300 of ST. To buffer VOUT, I thought about buffering the output in addition with an aluminum capacitor of 6800 µF in parallel to the recommended 4.7 µF. ...
3
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2answers
2k views

capacitor ripple current in buck converter

I'm designing a step-down buck converter and I'm a little bit worried about ripple current which flows through the output capacitors. In my research on the internet I found that ripple current is ...
3
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1answer
1k views

For which frequency is ESR specified by default?

I'm playing around with an REF5010 voltage reference, and its data sheet specifies an output capacitor with an ESR of 1 to 1.5Ω for best performance. Now when I measure the ESR of electrolytic ...
2
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4answers
1k views

ESR of Ceramic Capacitor

I have been doing a bit research on ceramic capacitors, as I need one for the output of my synchronous buck converter. And as its very common that ESR is not straight forwardly given in the data ...
2
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2answers
78 views

Buck Converter Capacitor and Inductor Characteristics

I'm trying to make a buck converter with this mickey-mouse MC34063A chip that will step-down +5V to +3V3 up to 500 milliamps. I've gone through the calculations by hand and validated them with an ...
2
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3answers
144 views

Low ESR capcitors for switching pre-regulator (LM2596)

In LM2596 switching regulator datasheet suggested to use low ESR capacitors. since I'm going to use LM2596 as a pre-regulator for a linear regulator to reduce the voltage drop on linear regulator, is ...
2
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2answers
510 views

What is an ESR zero in a power converter's output filter ? (#ExplainLikeI'm5)

I'm trying to understand this sentence (from this answer): So if your application has high ripple current and you don't need the ESR zero for stability then a low ESR cap will likely be the way ...
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3answers
4k views

Can I replace a general-purpose electrolytic capacitor with a low-ESR capacitor?

I have a dead PSU. I opened it up, and I found three bulging 1000 µF general purpose-type crappy electrolytic capacitors. I've replaced capacitors like this on several motherboards in the past, ...
2
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1answer
541 views

Is this capacitor suitable for boost converter (low ESR)?

I am about to build voltage booster (1.5V battery to 3.3V) with NCP1402. Datasheet recommends 68μF tantalum or two 22μF capacitors for output. Schematic looks like this: Output capacitor should have ...
2
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5answers
117 views

Capacitors: 200 mOhm ESR @ 100 Hz, attainable?

The MLCCs in 0805 case seem to have one or two orders of magnitude higher ESRs at that frequency. Are there any such low ESR caps out there, preferably 0805 MLCC but not compulsory? It is a 220 nF cap ...
2
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2answers
2k views

ESR in Electrolytic capacitor vs Voltage rating

I would like to know why in an electrolytic capacitor the ESR decreases as voltage rating increases. And why the current rating increases as voltage rating increases. Thank you.
2
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2answers
2k views

Range for low ESR capacitor

I'm new at the circuit design biz. I'm designing a battery powered device around the TI TPS61025 boost converter, and I'm rather confused about the proper range for the low-ESR output capacitor. The ...
2
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2answers
1k views

Crystal's datasheet give load capacitance is 20pF, do I need external load capacitors?

I use external crystal for HSE of STM32F0. I plan to use 8MHz Cylinder Crystals. Datasheet of this crystal below Datasheet give crystal load capacitance is 20pF My questions: 1/ Do I need to add 2 ...
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1answer
3k views

How to measure ESR

I have a bunch of capacitors but no clue of what ESR they have. Is there a way to measure the ESR? Can I set up a test circuit to measure it?
2
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1answer
2k views

LDO Output Capacitor Selection and ESR Consideration

For a simple application of a voltage regulator with 5V in and 3.3V out, I am looking at these three regulators. 1)AP2127K-3.3TRG1 2)MIC5504-3.3YM5-TR 3)TLV73333PDBVR They all have different ...
2
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2answers
498 views

Why does an increase in capacitor ESR make the capacitor hotter?

According to what I have read online, if a capacitor's ESR increases, the capacitor temperature will also increase and this has me left a little confused. Consider the simple single resistor circuit ...
2
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3answers
902 views

Do caps with a higher max voltage have lower ESR?

Does a capacitor of a higher max voltage, all other factors the same, have a lower ESR? If so, is the any relationship between the voltage and ESR differences?
2
votes
1answer
1k views

What is the impedance value that means it is a low ESR capacitor?

I need to select a 300uF capacitor and it is mentioned in the datasheet that it should be a Low ESR capacitor. However, it is not mentioned the impedance range or how much it should be. How can I ...
2
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4answers
357 views

Decoupling Capacitor Power Waste

I'm designing for a very power sensitive motor controller, and I'm concerned about the power that will be lost to the ESR of my decoupling capacitors. I have a prototype board as well, but there's no ...
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0answers
44 views

Supercapacitor as PMIC Storage Element

I'm currently trying to design a system that incorporates an ADP5092 which can use a supercapacitor as the storage element but I am also considering other similar PMIC chips so this is more for ...
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0answers
47 views

Strange Behaviour of Lipo Battery ESR during charging

I performed three charge tests on a single cell 190mAh Li-Po battery with Keithley Battery Simulator instrument. Charging started at 3V and stopped at 4.20V in all tests. After completing the three ...
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4answers
765 views

What's the impact of a crystal's frequency stability, ESR and load capacitance on micro-controllers?

I'm choosing a crystal for MK20DX256VLH7, but I can't seem to find enough information in MK20's datasheet for the oscillator. So, what I'm interested in knowing is: What is the impact of crystals' ...
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3answers
3k views

Choosing capacitors for a linear voltage regulator

I'm trying to use an LM1117 linear voltage regulator to convert to 3.3v (input voltage will be 9 or 5 volts; not yet decided). The datasheet suggests using 10uF tantalum capacitors on the input and ...
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2answers
535 views

How to find a capacitor for LDO that meets ESR requirements

I am searching an suitable input and output capacitor (for example MLCC) for following Low Dropout Regulator (LDO): Analog ADP151. The datasheet says that the ESR of the caps should be between 0.001 ...
1
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1answer
708 views

High value ceramic capacitors?

In a project, I am using the PTN78020H power supply, and it has a recommended circuit (from the datasheet linked above) that looks like this: Now on the input, it requests a massive 4 x 4.7uF ceramic ...
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2answers
83 views

stm32f7x2Rx vcap1 finding a suitable low ESR capacitor

According AN4661 In the STM32F7x2Rx devices, only the VCAP1 pin is available and must be connected to 4.7 µF low ESR between 0.1Ω and 0.2Ω ceramic capacitor. So how do I go about finding a ...
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3answers
648 views

Crystal's ESR or Frequency Stability/Tolerance, which is more of a priority?

I'll be using a 12MHz crystal, CL=20pF on an NXP chip. Currently choosing between lower ESR (60ohms vs 100ohms) or lower stability (50ppm vs 10ppm). Which spec is more important? Should I choose a ...
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1answer
245 views

What equivalent series resistance (ESR) capacitor should I replace bad one with?

I've got a bad clock capacitor in my original xbox that I'm trying to replace. It's a 1F 2.5V cap however, I'm not sure what Equivalent Series Resistance (ESR) the new cap should be. I see they sell 1 ...
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1answer
173 views

Bulk Capacitor Ripple Current as a Function of Capacitance

When you have a bulk capacitor on a time varying load, what is the relationship between the capacitance of the bulk capacitor, the ESR of the bulk capacitor and the ripple current through the bulk ...
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1answer
177 views

Surface mount capacitor value confirmation

I was just checking for some bad caps on my TV as I get a large distortion for a few minutes at power up. The power board looked fine but I noticed some aluminium surface mount caps were bulging ...
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2answers
2k views

Measuring internal resistance of a battery while it's being charged

I was startled to hear that there are devices out there that can measure the internal resistance of batteries, in circuit, while the batteries are being (trickle-)charged. For example, Hioki markets ...
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2answers
293 views

Is this inductor and caps a good choice for a buck converter?

I wanted to get together a simple and efficient 12V to 5V switching power regulator using only through-hole components that can be soldered to a nice protoboard. For my purposes, I need to provide 0....
1
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1answer
2k views

ESR and CSR of Capacitor

I'm trying to spec out an output capacitor for a TPS7201 voltage regulator (http://www.ti.com/lit/ds/symlink/tps7201.pdf). It needs to be selected carefully as it is used to stabilize the internal ...