Transcript Low ESR capacitors - NIC Components Corp.

LOW ESR CAPACITORS
FOR
HIGH CURRENT APPLICATIONS
NIC COMPONENTS GUIDELINE 012002
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
Increasing Need for
Lower ESR Capacitors
40A
Industry trends for next generation systems…

Higher Speed of Operation (1Ghz & up)

Lower Voltage of Operation (sub 2VDC)

Higher Current of Operation (40A & up)

Tighter Regulation Windows*
Low Voltage – High Current Requirements
Applications:
 Voltage Converters (AC/DC, DC/DC)
15A
5A
Increasing Current
Decreasing Voltage
of Operation
 Voltage Regulators
 Servers and Workstations
 High Current, Ultra-fast Transient Microprocessors
5.0V
3.3V
2.5V
1.3V
* Careful attention to circuit noise budget can ensure reliable system
operation and immunity to dreaded intermittent noise faults
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
C
ESR

I
IR
Pd = Power Dissipated (lost) within the Capacitor
Pd = I2 x ESR
Lower capacitor ESR = Lower Pd
Low
ESR capacitors helps to reduce the total circuit energy used!
Less
heat dissipation within the capacitor means it lasts longer!

Longer life & better reliability!
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
Intel is identifying maximum
ESR of output filter capacitors
to meet output voltage regulation limits
2.8V +0.1 -0.06V
VDC
Allowable Variation Window
Ripple Voltage(Vr)
Vr = I x ESR
INTEL VRM8.2
Voltage Regulator Module
2700uF/10VDC/0.034 ESR max.
Low ESR Capacitor
NIC SMT version: NACZF332M16V18X22TR (0.028 Z)
NIC LEADED version: NRSZ272M10V12.5X25 (0.032 Z) NRSX272M10V12.5X25 (0.02
When used in output filter
Lower capacitor ESR = Lower output ripple voltage (Vr)
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
Noise budgets help maintain signal integrity in low-voltage systems
An ideal power supply has zero output impedance across all frequencies and load currents.
However, the inductances associated with cables, bus bars, connectors, pc boards, and IC
packages introduce impedances that increase with frequency.
Thus, an IC's supply voltage is not rock-solid.
Bulk, or low-frequency, decoupling is the first layer of defense against unwanted
impedances. This decoupling keeps the load voltage from drooping when there is a step
change in current at the load, that's too short for the power supply to respond. You need
enough capacitance to supply all the charge required by the ICs during this time without
letting the power-bus voltage droop below the limit allowed by your power noise
budget, (Delta)V.
Greg Edlund is a principal hardware engineer at Digital Equipment Corp (Maynard, MA), where he does signal-integrity engineering for
the Alpha server project. Edlund was formerly a member of the team that designed the SS-1 supercomputer. He holds a BS in physics
from the University of Minnesota Institute of Technology (Twin Cities).
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
Noise budgets help maintain signal integrity in low-voltage systems
The first layer of defense:
To get…”enough capacitance to supply all the charge” required by the circuit…
Typically, designers use electrolytic cans (Radial & SMT) at the PCB power entry
point (Output filter of the power supply)and spread tantalum & ceramic capacitors
across the board.
Important issue:
“if your design requires a large amount of low- or mid-frequency current, place a local dc/dc
converter near the loads. This local power source cuts the bus inductance and leaves only the
pc-board and IC-package inductances.“
DC– DC Converters use Low ESR Capacitors in output filters
Low ESR = Lower voltage fluctuation
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
Selecting By-Pass – Decoupling Capacitors
To minimize line voltage fluctuation under high load current
conditions Low ESR bypass- decoupling capacitors are required.
Lower capacitor ESR = Lower voltage fluctuation
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
LOW ESR POLYMER CATHODE
TANTALUM ELECTROLYTIC CAPACITORS
Market & Technology: Use of POLYMER in place of MnO2 for CATHODE results in low ESR,
high ripple current ratings (RCR) and suppression of combustion (will not support flame)
under failure. Applications in high density low voltage – high current power management
designs. Larger sizes C & D/V cases continue to be popular. Expansion will cover all sizes P ~
D/V. New NTP series parts developed include lower ESR 0.025-ohm products, and we will
achieve 0.020 ohm later in 2002.
Higher Conductivity of
polymer results in
reduced ESR
Conductive polymer
(polypyrrole) cathode
(replaces manganese dioxide)
for low ESR – high ripple
current applications.
Comparison of
Conductivity
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
LOW ESR POLYMER CATHODE
TANTALUM ELECTROLYTIC CAPACITORS
Comparison of Capacitance over Temperature
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
LOW ESR POLYMER CATHODE
TANTALUM ELECTROLYTIC CAPACITORS
10uF / 16VDC ALUMINUM
10uF / 6.3VDC P/N: NTP100M6.3TRA
100uF / 16VDC P/N: NTP101M16TRD
Comparison of ESR over Temperature
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POLYMER ELECTROLYTE
SOLID ALUMINUM ELECTROLYTIC CAPACITORS:
NSP Series
also see www.lowESR.com
Technology:
Replacement of liquid electrolyte with SOLID POLYMER results in ultra low ESR and high
RCR with long life at high temperature. Primarily used in low profile high current – low
voltage power management applications. Same size as D/E (7343) tantalum lends itself to
replacing multiple chip tantalum types. Lowest 100KHz ESR (0.012ohm) and highest RCR
(3.0Arms) of all SMT E-Caps. Higher capacitance low ESR parts are expected to dominate
production in future. Higher capacitance values (330uF / 2VDC) Lower profile version (1.5mm
max thick) special will be available for height restrictive applications.
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
Surface Mount Aluminum Electrolytic Capacitors
MOLDED FLAT CHIP SOLID ALUMINUM
NSP Series
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LOW LOSS CAPACITORS FOR
HIGH CURRENT APPLICATIONS
ESR & Impedance (Ohm)
Surface Mount Aluminum Electrolytic Capacitors
MOLDED FLAT CHIP SOLID ALUMINUM
P/N: NSP220M6.3TR
22uF / 6.3VDC
Impedance
ESR
Sub 0.020 ESR
Frequency
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SOLID ALUMINUM ELECTROLYTIC CAPACITORS:
New Products
NSPZ Series - Low ESR Solid Aluminum
Electrolytic Capacitors in SMT V-Chip
» Capacitance values from 15uF ~ 680uF
» Voltage ratings form 4 ~ 25VDC.
» Case sizes (DxL) include:
 6.3mm x 6.3mm
 8mm x 7mm
 10mmx 8mm
NIC Components continues to address the growing needs for low ESR capacitors with the
release of the NSPZ series of surface mount (SMT) solid polymer electrolyte aluminum
electrolytic capacitors. NSPZ series features:
 Ultra-low ESR and impedance (as low as 0.025ohm)
 High ripple current ratings (up to 2.5Arms; +105ºC/100KHz)
 Ideally suited for lower voltage - high current power management applications, including
dc-dc converters and switchers.
Rated for operation at temperatures between -55 ~ +105ºC and are compatible with reflow
soldering processes. The devices are supplied in tape-and-reel packaging for use with
automated pick-and-place manufacturing systems.
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SMT ALUMINUM ELECTROLYTIC CAPACITORS:
HYBRID ELECTROLYTE
NSPE Series - Low ESR Hybrid Electrolyte
Electrolytic Capacitors in SMT V-Chip
» Capacitance values: 22uF ~ 820uF
» Voltage ratings: 4 ~ 16VDC
» Case sizes (DxL) include:
 6.3mm x 6.3mm
 8mm x 10.8mm
 10mm x 10.8mm
Featuring the low ESR characteristics of solid electrolyte types, but at lower cost, NIC's new
hybrid (solid -liquid electrolyte) NSPE series of surface mount (SMT) aluminum electrolytic
capacitors provide cost effective solution for power management applications. NSPE
series uses combination solid polymer and liquid electrolyte toreduce the ESR characteristic
and increase the ripple currentrating. NSPE series features low ESR and impedance (as low as
0.023ohm) with high ripple current ratings (up to 2.18Arms;+105ºC/100KHz).
Ideally suited for lower voltage - high current power management applications, including
power supplies, dc-dc converters and switchers. Rated for operation at temperatures between
-55 ~ +105ºC and are compatible with reflow soldering processes.
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SMT ALUMINUM ELECTROLYTIC CAPACITORS:
HYBRID ELECTROLYTE - ESR over Frequency Comparison
NSPE Series - Low ESR Hybrid Electrolyte Electrolytic Capacitors in SMT V-Chip
SMT Aluminum Electrolytic Capacitors V-Chip style
100uF / 6.3VDC values shown
Standard Liquid Electrolyte (BLUE LINE) and Hybrid [Solid - Liquid] Electrolyte (RED
LINE)
Hybrid Electrolyte [ NSPE Series ] exhibits significantly lower ESR over wide frequency range
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SMT ALUMINUM ELECTROLYTIC CAPACITORS:
HYBRID ELECTROLYTE - ESR over Temperature Comparison
NSPE Series - Low ESR Hybrid Electrolyte Electrolytic Capacitors in SMT V-Chip
SMT Aluminum Electrolytic Capacitors V-Chip style
100uF / 6.3VDC values shown
Standard Liquid Electrolyte (BLUE LINE) and Hybrid [Solid - Liquid] Electrolyte (RED
LINE)
Hybrid Electrolyte [ NSPE Series ] exhibits less
significantly
change over
lowertemperature
ESR over wide
andfrequency
significantrange
improved
at low temperatures
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NEW TECHNOLOGY COMPONENTS:
New Product
Niobium Electrolytic Capacitors
Niobium is one of the alternatives being considered to replace tantalum in capacitors - as
tantalum becomes less available and human rights issues are raised about some of its African
sources. Estimates, niobium is over 100 times more plentiful than tantalum (less than 1/10th
the cost). NIC’s NBP series has same construction as conductive polymer cathode tantalum
(NIC NTP Series). It is anticipated that in the future, niobium capacitors will be used for highcapacity devices (up to 1000µF), which are too costly to produce using tantalum.
NIC’s niobium capacitor at a glance
Specifications:
Rated Voltage
2.5V
Capacitance
220uF
Size
(D) 7.3 x 4.3 x 2.8mm
ESR
0.055ohms
Part Number
NBP series (specifications in development)
Samples
Now
Production
Early 2002
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NEW TECHNOLOGY COMPONENTS:
Niobium Electrolytic Capacitors
Typical ESR over Frequency Comparison: SMT Electrolytic Capacitors
220uF D-Case 2.5 ~6.3VDC
Niobium / Polymer Cathode Tantalum / Standard MnO2 Cathode Tantalum
0.180
NTP - Polymer Cathode Tantalum
0.160
NTC-T Standard MnO2 Cathode Tantalum
0.164
NBP - Polymer Cathode Niobium
0.140
ESR (ohm)
0.120
0.125
0.100
0.087
0.080
0.085
0.080
0.060
0.058
0.040
0.044
0.040
0.027
0.024
0.020
0.020
0.023
0.019
0.021
0.018
0.000
1KHz
10KHz
100KHz
Frequency
NIC COMPONENTS CORP.
500KHz
1MHz
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NEW TECHNOLOGY COMPONENTS:
Niobium Electrolytic Capacitors
Typical Leakage Current over Voltage (VDC) Comparison: SMT Electrolytic Capacitors 220uF DCase 2.5 ~6.3VDC
Niobium / Polymer Cathode Tantalum / Standard MnO2 Cathode Tantalum
100.000
Niobium LC Spec = 0.5CV = 280uA Max.
18.834
10.000
NTP - Polymer Cathode Tantalum
NTC-T Standard MnO2 Cathode Tantalum
NBP - Polymer Cathode Niobium
Leakage Current (uA)
3.394
1.000
Tantalum LC Spec = 0.1CV = 139uA Max.
1.288
0.378
0.374
0.100
0.038
0.014
0.010
0.005
0.034
0.011
0.005
0.001
0.5V
1V
2.5V
Applied Voltage (VDC)
NIC COMPONENTS CORP.
6.3V
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REFERENCE: September 2001 - PRODUCT HIGHLIGHT - EPN
Low ESR capacitors come to the fore
There is a rapidly increasing demand for low equivalent series resistance (ESR) capacitors in a small case, surface mount format.
But what exactly is ESR, why is it important and what products are on offer to satisfy the market's hunger for these devices?
ESR is an abbreviation for Equivalent Series Resistance, the characteristic representing the sum of
resistive (ohmic) losses within a capacitor. While ESR is undesirable, all capacitors exhibit it to some
degree. Materials and construction techniques used to produce the capacitor all contribute to the
component's ESR value. ESR is a frequency dependent characteristic, so comparison between component
types should be referenced to same frequency. Industry standard reference for ESR is 100kHz at +25°C.
Power dissipation within the capacitor, and the effectiveness of the capacitor's noise suppression
characteristics will be related directly to the ESR value.
Why do we need low ESR?
An industry wide trend towards lower voltage, higher current circuit design, fuelled by lower voltage
silicon devices is causing designers to specify capacitors with minimal ESR. Higher levels of functionality in
today's designs mean that despite voltage levels falling, circuit power levels have not dropped accordingly.
Ohms law tells us, in very simple fashion, that at the same power dissipation level, lower voltage
operation will mean higher current levels. This greatly increases the demands on the power management
circuit (power supply or DC/DC converter) to deliver energy during periods of high current load stepping.
Lower voltage circuit operation also imposes greater restrictions upon the output voltage variation levels.
The output capacitors or capacitor bank, used in the power management circuit, need to exhibit low ESR
characteristics. Ripple voltage (noise) on the output supply voltage will be directly proportional to the ESR
of the capacitors used. By considering the formula: Vr = I x R, where Vr is the ripple voltage and R is the
ESR, we can see that if the current (I) increases from, say, 4A to 20A then the ripple voltage will also
increase by a factor of five. Increased ripple voltage (Vr) cannot be tolerated in today's and next
generation designs. This is driving the demand for lower ESR capacitors.
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TECHNOLOGY:
What's on Offer?
The high capacitance values (typically greater than 100uF) that are needed to supply energy to the
circuit during high load current stepping, are most often achieved through the use of multiple SMT
electrolytic capacitors. Surface mount devices are often preferred to leaded parts as they simplify PCB
assembly and allow closer component placement. Low ESR SMT electrolytic capacitors mainly fall into four
categories. Liquid electrolyte, vertical can chip aluminium electrolytic capacitors offer the highest values of
capacitance and low ESR. They tend to be low cost, but have case sizes that are large compared to other
constructions.
Solid electrolyte, resin encapsulated flat chip aluminium electrolytic capacitors feature reduced ESR, very
high ripple current ratings and reduced size at a higher cost. Solid 'dry' electrolyte also greatly extends
the operational life of the component when used at high temperature. Solid electrolyte, resin
encapsulated flat chip MnO2 cathode tantalum electrolytic capacitors again offer low ESR. They are
produced with a manganese dioxide cathode construction. Solid electrolyte, resin encapsulated flat chip
polymer cathode tantalum electrolytic capacitors are available as ultra-low ESR versions. These are
produced using a speciality polymer cathode construction. The Standard manganese dioxide cathode
(MnO2) being replaced by a highly conductive polymer (polypyrrole) cathode that considerably reduces
ESR. Indeed, the conductivity of polypyrrole is more than 100 times that of manganese dioxide.
Circuit designs incorporating lower voltage semiconductors and ICs are driving increasing demand for
better and lower ESR capacitors. SMT low ESR type electrolytic capacitors offer the combined solution of
high capacitance, to supply energy during high-speed load stepping, and low ESR to reduce the output
filter ripple (noise) voltage to meet the needs of today's and tomorrow's power management design
challenges.
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