4
Foreword
High speed switch mode power supplies place high
demands on the capacitors used in the input or output
filters of Resonant DC-DC or Pulse Modulated DC-DC
converters. Olean Advanced Products, a division of
AVX Corporation has developed two multilayer ceramic
(MLC) capacitor series (SM and SK) for these switcher
applications. These capacitors have been extensively
tested and characterized and found to have almost
ideal performances to meet the stringent requirements
of these applications.
Input Filter Capacitor
The Input Filter capacitor is required to perform two
functions: To supply an unrestricted burst of current to
the power supply switch circuitry and to not only do it
without generating any noise, but to help suppress
noise generated in the switch circuitry. It is, in effect, a
very large decoupling capacitor. It must have very low
ESL, capabilities for very high dv/dt, as well as di/dt
and it must have a very low ESR to eliminate power
loss.
The distance from the primary DC source, as well as
the type of capacitor used in this source (usually elec-
trolytics), presents a very high inductance to the input
of the Switcher. The MLC input capacitor, with its
excellent ESL and ESR characteristics, is located
physically close to the switch circuitry. Repetitive peak
currents, inherent with the Switcher design, require a
high ripple capability, as well as high surge capability
for transients, both induced and conducted from other
sources. MLCs have both these capabilities.
Output Filter Capacitor
The output from the switching circuit of a Switcher
consists of current on and off. From an elevated DC
reference, this current is an AC ripple additive on the
DC. In order to smooth this ripple effect, a filter circuit
(usually inductive input) is built to allow a storage of
energy to take place during the rising ripple portion
and to allow a discharge of energy during the falling
ripple portion.
The ESR and ESL of the capacitor contribute to the
net ripple effect. The output filter capacitor is chosen
for ESR, and with previous types of capacitors, multi-
ples were used in an attempt to lower the net ESR.
The MLC offers ESRs well below the minimum allow-
able to lower noise levels, thus eliminating the need for
multiple units.
Other MLC Capacitors for
SMPS Applications
Advanced Products also manufactures line filter,
coupling, decoupling, resonant and snubber capacitors
for SMPS applications. Contact OLEAN ADVANCED
PRODUCTS for Application Specific S.M.P.S. capacitor
requirements (716-372-6611).
SMPS Capacitors
SMPS Capacitors Performance
5
SMPS Capacitors
SM & SK Series/SMPS Capacitors
Capacitor Performance
SMPS Design Information (SM and SK Series)
Absolute Maximum Output Capacitance
Assuming no ESL and no ESR
25
20
15
10
5
0
Load Current - Amps
0 5 10 15 20
Maximum Output Filter Capacitance
2 MHz 1 MHz
500 KHz
250 KHz
( F)
m
Absolute Maximum Capacitance ESL
Assuming no ESR - Capacitive Induced Ripple
25
20
15
10
5
0
Load Current - Amps
0 5 10 15 20
Maximum Output Filter Capacitance ESL
(nH)
SM Series
SK Series
250 Khz
500 KHz
1 MHz
2 MHz
50 mv Noise
Due to ESL
Absolute Maximum Capacitance ESR
Assuming no ESL - Capacitive Induced Ripple
25
20
15
10
5
0
Load Current - Amps
0 10 20 30 40
Maximum Output Filter Capacitance ESR
(mOhm)
50 mv Noise
Due to ESR
SM Series
SK Series
m
m
m
m
m
m
AI Electrolytic
15 F
MLC SM02
10 F
Wet Ta
10 F
Solid Ta
5.6 F
MLC SM04
4.7 F
10 10 10 10 10
Capacitance ( F)
0
2
4
6
8
10
12
14
16
Time (Seconds)
-5
-6
-7
-8-9
Capacitance as Measured from dv/dt Slope
200 mA/nS Current Pulse
Measurement starts after Inductive Ring Decay
6
SMPS Capacitors
Capacitor Performance
AC Ripple Capability (SM_, SK_, SV_ and
High Voltage Chip Capacitors)
Due to the wide range of product offering in this cat-
alog, the AC ripple capabilities for switch mode power
supply capacitors (SM_ & SK_) and high voltage
capacitors (SV_ & SMD) are provided in the form of
IBM compatible software package called CALCI. The
3.5" diskette with a compiled, executable file can be
obtained by filling out and mailing the form enclosed in
this catalog.
CALCI program will provide answers to most of the
design engineers’ questions on critical parameters for
their specific applications:
• Equivalent Series Resistance
- function of frequency and temperature
• Equivalent Series Inductance
- function of design
• Self Resonant Frequency
f = 1/ (2 x πL x C)
• Thermal Characteristics
- function of design
• AC Ripple Capabilities
- function of frequency, temperature and
design
Î
TYPICAL ESR -vs- Frequency
FOR SM04 STYLE CAPACITORS
1uF 4.7uF 9uF
ESR (Ohms)
10.000
1.000
0.100
0.010
0.001
1.0 10.0 100.0 1000.0
Frequency (kHz)
MAXIMUM RMS CURRENT FOR 50 WVDC, SM - Z5U
@ 100 KHz & 258C Ambient
ASSUMING MAX. CAP. FOR SINGLE CHIP CONSTRUCTION
100 KHz ARMS
50
45
40
35
30
25
20
15
10
5
030.9 29.3 16.0 6.0 3.3 40.1
SM01 SM02 SM03 SM04 SM05 SM06
STYLE
MAXIMUM RMS CURRENT FOR 50 WVDC, SM - X7R
@ 100 KHz & 258C Ambient
ASSUMING MAX. CAP. FOR SINGLE CHIP CONSTRUCTION
100 KHz ARMS
50
45
40
35
30
25
20
15
10
5
028.6 29.1 15.4 6.3 3.5 42.7
SM01 SM02 SM03 SM04 SM05 SM06
STYLE
MAXIMUM RMS CURRENT FOR 25 WVDC, SK - Z5U
@ 100 KHz & 258C Ambient
ASSUMING MAX. CAP. FOR EACH STYLE
100 KHz ARMS
20
18
16
14
12
10
8
6
4
2
01.4 1.9 3.2 4.6 6.6 11.1 12.1 17.8
SK01 SK02 SK03 SK04 SK05 SK06 SK07 SK08
STYLE
14
SMPS Capacitors
SK Series/SMPS Capacitors
Product Offering – C0G, X7R
and Z5U
Olean Advanced Products’ SK series are conformally
coated MLC capacitors for input or output filtering in
switch mode power supplies. They are specially
processed to handle high currents and are low
enough in cost for commercial SMPS application.
SK 01 3 E 125 Z A A
How to Order:
Style Size Voltage Temperature Capacitance Capacitance Failure Leads
See chart 25V = 3 Coefficient Code Tolerance Rate A = Does not
below 50V = 5 Z5U = E (2 significant Z5U: Z = +80, -20% A = Does apply
100V = 1 X7R = C digits + no. P = GMV not apply
200V = 2 C0G = A of zeros) X7R: K = ±10%
500V = 7 22 nF = 223 M = ±20%
220 nF = 224 Z = +80, -20%
1 µF = 105 C0G: J = ±5%
100 µF = 107 K = ±10%
M = ±20%
Maximum Capacitance Values (C0G), µFd Maximum Capacitance Values (X7R), µFd
Style 50 WVDC 100 WVDC 200 WVDC 500 WVDC
SK01 .012 .010 .0056 .0018
SK03 .047 .039 .022 .0068
SK04 .10 .082 .047 .015
SK05 .15 .12 .068 .022
SK06 .47 .39 .22 .068
SK07 .56 .47 .27 .082
SK08 1.10 .82 .47 .15
Style 50 WVDC 100 WVDC 200 WVDC 500 WVDC
SK01 0.27 0.15 0.082 0.033
SK03 1.0 0.56 0.39 0.15
SK04 2.2 1.2 0.68 0.27
SK05 3.3 1.8 1.2 0.39
SK06 10 5.6 3.9 1.2
SK07 14 8.2 4.7 1.8
SK08 22 15 8.2 3.3
Maximum Capacitance Values (Z5U), µFd
Style 25 WVDC 50 WVDC 100 WVDC 200 WVDC
SK01 1.2 0.82 0.47 0.33
SK03 5.6 3.30 2.20 1.50
SK04 10.0 8.20 4.70 3.90
SK05 18.0 10.00 6.80 4.70
SK06 47.0 39.00 22.00 15.00
SK07 68.0 47.00 27.00 18.00
SK08 120.0 100.00 47.00 33.00
15
SK Series/SMPS Capacitors
Product Offering – C0G, X7R and Z5U
LH
T
M
LD
LS
LL
DIMENSION CHART
Style L (max.) H (max.) T (max.) LS (nom.) LD (nom.)
SK01 0.200 0.200 0.200 0.200 0.020
SK03 0.300 0.300 0.200 0.200 0.020
SK04 0.400 0.400 0.200 0.200 0.020
SK05 0.500 0.500 0.200 0.400 0.025
SK06 0.870 0.600 0.200 0.790 0.032
SK07 1.100 0.600 0.200 0.980 0.032
SK08 1.100 0.600 0.350 0.980 0.032
L -= Length T = Thickness LS = Lead Spacing (Nominal ±0.031)
H = Height M = Meniscus (0.060 max.) LL = Lead Length (2" max./1" min.)
LD = Lead Diameter (Nominal ±0.002)
SK01 SK03 – SK08
L
H
M
LD
LL
LS
