LowESR.com - Resource for Low ESR Capacitors

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Low ESR Capacitors
(Tech support: tpmg@niccomp.com)

Demand for low ESR (ESR = Equivalent Series Resistance) surface mount (SMT) capacitors continues to grow due to industry wide trend towards distributed power management driven by lower voltage circuit design (powering lower voltage silicon devices). Higher levels of complexity - functions in today's designs means the power levels have not decreased with voltage.

Ohm's law gives us I = P/V If within an electronic circuit the operation voltage (V) decreases (example from 5V to 1.0V) and the power (P) remains constant (example 20W) we see that circuit current (I) level increases from 4Amp to 20A respectively. The power management circuit needs to supply high current at low voltage, with minimal noise (ripple voltage).

The output capacitor (or capacitor bank) will have a ripple voltage (seen as noise on the supply voltage) proportional to the ESR of the capacitor (or capacitor bank).

V = I X Rs ... Ripple voltage = Current X ESR

If the current increases from 4A to 20A, within a circuit, the ripple voltage will increase by a factor of FIVE. Increased ripple noise typically cannot be tolerated, so the ESR of the capacitors must be reduced.

Compounding the need for low ESR further, is the reduced circuit (silicon) tolerance to voltage variation (noise and line droops).

NPC Series

Solid Aluminum
Polymer Electrolyte

Ultra Low ESR
Molded Flat Chip

100KHz ESR = 0.0045ohm
100KHz RCR = 3.9Arms

Build FREE Kit including NPC Part Numbers [LINK]

Frequency Characteristics [LINK]

Polymer Cathode
Tantalum Chip Capacitors
NTP series: [ LINK ]

22 Part Numbers Added
2.2μF to 1,000μF
Low ESR to 0.006 Ω
High Ripple Current Ratings
Suitable for SAC Alloy Reflow
EIA J, P, A2, A, B2, B, C2, C, V & D Case Sizes

Robustness of Surface Mount Aluminum Electrolytic Capacitors to Pb-Free Reflow Soldering

IPC/JEDEC / CARTS Europe / PCI Magazine

Compliance - Soldering Heat Limits
Guides & Support

Expanded - Hybrid Construction
Low ESR Aluminum Electrolytic Capacitors

Hybrid Construction Advantages:
Higher VDC & Temperature Ratings than Solid Polymer Alum E-caps
Low ESR & High Ripple Current Ratings (RCR)
High Voltage; up to 125DC
Wide Temperature -55°C to +135°C
Extended life: 10,000 hrs @ +105°C
Low ESR - Z at low temperature (-55°C) [LINK]
High Capacitance; up to 1000uF
Surge & Transient Resistant - Open mode failure
Reduces number of components per PCB
Specifications, Samples & More Information

High capacitance value (>100uF) electrolytic capacitors are needed (and commonly called out) within today's power management circuits to deliver energy during high load current stepping. MLLC (ceramic chip capacitors) are also used in >1uF (typically X7R / X5R) due to even lower ESR provided by these types. Multiple capacitors (capacitor bank) using electrolytic and MLCC types are often used, to supply the energy needed during rapid changes in load current demand, as seen by the power management circuit. Virtually every segment of the electronics industry is using - requiring low ESR capacitors. All the major capacitor producers are offering (or developing) lower ESR electrolytic capacitor products.

1uF ~ 100uF Ceramic Chip Capacitors
2.2uF ~ 1000uF Polymer Cathode Tantalum E-Caps
2.2uF ~ 560uF Solid Aluminum Polymer E-Caps
>1000uF Radial Leaded Low ESR Aluminum E-Caps

Low ESR Capacitor Resources: Articles & Papers
	"Physical and Electrical Characterization of Polymer Aluminum Capacitors" [link] - CARTS USA 2010 MEI Technologies Inc/NASA
	Paralleling Capacitors Differences in maximum ripple current and ESR can lead to a shift in the ripple current – and premature failure [link]
	Low ESR Capacitors [ link ] Low ESR Capacitor Trends [ link ]
	Electronic Component News Web Exclusive: "An Introduction to Low ESR Capacitors" [link ]
	Electronic Product News "Low ESR capacitors come to the fore" [ link ]
	Components In Electronics "Passive demands tighten as voltages drop" [ link ]