CAP-XX Purpose User manual

User manual for APPEB1002 Revision 2.1, Oct 2019
General Purpose CAP-XX Supercapacitor Evaluation Board
© CAP-XX Pty Limited 2019 | Tel [phone] | www.cap-xx.com
Page 1of 8
08
Fall$
Evaluation board user manual
APPEB1002
User Manual for
APPEB1002 General
Purpose CAP-XX
Supercapacitor Evaluation
Board
Author: Henry Huang
Revision 2.1, Oct 2019

User manual for APPEB1002 Revision 2.1, Oct 2019
General Purpose CAP-XX Supercapacitor Evaluation Board
© CAP-XX Pty Limited 2019 | Tel [phone] | www.cap-xx.com
Page 2of 8
User Manual for APPEB1002 Revision 2.1, Oct 2019
General Purpose CAP-XX Supercapacitor
Evaluation Board
Author: Henry Huang
Features
PCB supports all CAP-XX supercapacitors
•Supports all CAP-XX prismatic
supercapacitor footprints
•Supports all CAP-XX cylindrical
supercapacitor products
•Supports both single and dual cell
device
Multiple charging options
•Direct charging – no current limit
•Simple CAP-XX soft-start design
•Full current limit design
Multiple cell balancing options
•Single cell, no balancing
•Resistor balancing
•Very low quiescent current active
balance
Easy to use
•Purchase from CAP-XX, visit
www.cap-xx.com or email
[e-mail]
Description
The APPEB1002 evaluation board allows quick assessment of various design options for a
supercapacitor. It is primarily designed to evaluate the performance of a supercapacitor for peak
power or backup power delivery when coupled with any energy source.
This evaluation board can handle all variants of CAP-XX supercapacitor products. It provides three
distinct charging methods, two options for cell balancing and multiple test points for voltage
monitoring. The board has one input terminal and one output terminal which is directly connected
to the supercapacitor. All user configurable resistors can accommodate SMD 0603 chip resistors or
5mm pitch through hole resistors.
The use of solder jumpers on the board allows the user to completely disable unused circuitry to
minimise power consumption. When all options are disabled the supercapacitor has zero load on it,

User manual for APPEB1002 Revision 2.1, Oct 2019
General Purpose CAP-XX Supercapacitor Evaluation Board
© CAP-XX Pty Limited 2019 | Tel [phone] | www.cap-xx.com
Page 3of 8
and the voltage on the capacitor is only affected by its own self discharge. This feature makes the
board suitable for prototyping in low power applications.
The board, however, does not have any input voltage regulation built in. The user needs to limit the
input voltage supplied to the board to be ≤the rated voltage of the supercapacitor.
APPEB1002 Circuit
Figure 1: schematic for APPEB1002
The circuit of APPEB1002 is shown in Fig1. Looking at the schematic from left to right the circuit
blocks are: Input, Charging circuitry, Cell balancing circuitry, Supercapacitor and Output terminal.
Terminal CON1 takes the input power. JP1 is a 6 pin jumper link which selects one of three
charging methods.
C3, C4 and C5 are options for where the supercapacitor is fitted and only one supercapacitor
should be installed.
Terminal CON2 is the output of the evaluation board, that is directly connected to the
supercapacitor.
Installation of supercapacitor
The APPEB1002 board has number of solder pads and through holes laid out on the PCB to cater
for all CAP-XX supercapacitor product lines with different prismatic and cylindrical package types,
single cell or dual cell configurations. The resulting landing pad design is somewhat complex. In
this section the correct installation of all types of CAP-XX supercapacitor will be explained.
CAP-XX prismatic supercapacitors
CAP-XX has 4 package types for the prismatic line from the smallest to the biggest they are: Z, A,
W and S. These package types single and dual cell supercapacitor options.
Dual cell prismatic supercapacitors
All dual cell supercapacitors have the positive and negative pins at the same location, but the
different footprint between packages changes the balancing terminal location. The PCB has clearly
labelled silkscreen to orient the part. The following illustrations in figure 2 demonstrate the correct
ways to install prismatic dual cell parts.
Current
Limit block
Balancing Block

User manual for APPEB1002 Revision 2.1, Oct 2019
General Purpose CAP-XX Supercapacitor Evaluation Board
© CAP-XX Pty Limited 2019 | Tel [phone] | www.cap-xx.com
Page 4of 8
Figure 2: illustration to correctly installing prismatic dual cell device
Single cell prismatic supercapacitors
There is an inconsistency of the terminal locations between W/S packages and that of A/Z
packages. Hence when installing the W and S package single cell, they have to be rotated 180!as
shown in figure 3 below.
Figure 3: illustration to correctly installing prismatic single cell device
CAP-XX cylindrical cells
CAP-XX’s cylindrical products, labelled as the GY series has a range of capacitance from 1F to
100F in radial lead form.
The APPEB1002 board only supports single cell radial lead GY products. They can be installed as
a single cell or two cells in series to form a dual cell on the PCB. CAP-XX’s radial leads GY line
currently has 6 different diameters but with only three different pin pitches. The PCB through hole
design for our GY cells has one positive through hole and three negative through holes for the
negative pin corresponding to the different pitches. When installing a GY series cell, first place the
positive into the hole marked + then slide the negative pin of the cell into one of the negative
through holes with the correct pitch. Figure 4 below is a sample illustration.

User manual for APPEB1002 Revision 2.1, Oct 2019
General Purpose CAP-XX Supercapacitor Evaluation Board
© CAP-XX Pty Limited 2019 | Tel [phone] | www.cap-xx.com
Page 5of 8
Figure 4: illustration for installing a GY cell to APPEB1002
If only a single GY cell is required there must be a wire link made to short out the unused GY cell
positive and negative pins, shown as a red wire in the right side of figure 5. When two GY cells are
needed, both cells should be installed as shown above and the two GY cells must be identical
parts as illustrated on the left side of figure 5. Even though dual cell cylindrical modules are
available from CAP-XX, the APPEB1002 requires using 2 separate single cells in series. This
allows evaluation of different balancing options. The dual cell modules have their balancing circuit
built in so instead of using a GY25R51B22S505R0, 5F, 5.5V dual cylindrical cell module, use 2 x
GY12R71B020M106R 10F, 2.7V cells in series.
Figure 5: illustration of GY cell configuration, left – dual cells, right – single cell
Charging options
There is a 6-pin header located near the power input terminal that function as a link jumper to
easily change charging methods.
Direct Charging
This option connects the input directly to the supercapacitor without any protection or current limit.
This should only be used if the input power source is high impedance or the source has its own
current limit. To enable this option, place the jumper link on the top row of header marked Direct

User manual for APPEB1002 Revision 2.1, Oct 2019
General Purpose CAP-XX Supercapacitor Evaluation Board
© CAP-XX Pty Limited 2019 | Tel [phone] | www.cap-xx.com
Page 6of 8
connecting pins 5 & 6 of JP1, and leave solder jumper I Limiter ENABLE (SJ2) and Soft-Start
ENABLE (SJ1) open as shown on the left of figure 6. The PCB trace can withstand a maximum 5A
continuous current. This must be considered when using the direct charge option.
Soft-start charging
To enable charging via the low-cost CAP-XX soft-start circuit, place the jumper link on the second
row of the header marked Soft-start connecting pins 3 & 4 of JP1, leave solder jumper I Limiter
ENABLE (SJ2) open and solder a bridge connecting Soft-Start ENABLE (SJ1) as shown in the
middle of figure 6.
The sub circuit containing R1, R2, M1 and M2 is the soft-start cell charging design. Initially PFET
M1 is ON and the supercapacitor charges through power resistor R2, default value 5.6Ω. When the
supercapacitor charges to ~400mV below the input voltage, M1 will turn OFF, enabling R1 to pull
gate of PFET M2 to 0V, turning M2 ON which effectively short circuits the positive input terminal to
the positive terminal of the supercapacitor. For more information of the operation of this circuit
please refer to the Simple soft-start circuit in CAP-XX Application Note AN1001_Current_Limit Rev
4.0, available on our website.
Constant current limit charging
To enable charging through the TPS2553 constant current limit IC, place the jumper link on the
third row of the header marked I limiter connecting pins 1 & 2 of JP1, leave solder jumper Soft-
Start Enable (SJ1) open and solder a bridge connecting I Limiter ENABLE (SJ2) as shown on the
right of figure 6.
Components C6, IC1, R3 and C2 forms the constant current charging option. Solder jumper SJ2
connects this sub circuit to the supercapacitor. IC1, TPS2553 is a power distribution switch with
active constant current limit. Its current limit level is determined by R3, default value is 47kΩfor a
current limit of 556mA. However, this can be easily changed to any desired resistor, either an SMD
0603 or 5mm pitch through hole resistor. Since this IC may throttle its current limit level when it
gets hot, the charging time could be significantly longer than calculated if set current limit is too
high. The current limit threshold equation is given in the IC’s datasheet as:
𝐼!"#! 𝑚𝐴 =
23950
𝑅3!.!""𝑘Ω
For more information regarding on this circuit refer to the Integrated Current Limit Solution in in
CAP-XX Application Note AN1001_Current_Limit Rev 4.0, available on our website. For more
information on the TPS2553, please refer to Texas Instrument’s webpage
http://www.ti.com/product/TPS2553

User manual for APPEB1002 Revision 2.1, Oct 2019
General Purpose CAP-XX Supercapacitor Evaluation Board
© CAP-XX Pty Limited 2019 | Tel [phone] | www.cap-xx.com
Page 7of 8
Figure 6: three charging modes with APPEB1002
Cell balancing options
When a dual cell supercapacitor or two GY series cells are used, cell balancing is strongly
recommended, refer to CAP-XX Application Note AN1002 Cell Balancing Rev1.0 available on our
website.
When using single cell supercapacitor, all cell balancing option must be disabled. For more
information regarding cell balancing, please refer to CAP-XX Application Note AN1002_Cell
balancing on our website.
No cell balancing
When the board is fitted with a single cell supercapacitor resistors R7 and R8 must be left
unpopulated and solderable jumpers marked as Active Balance POWER (SJ3) and Balance output
ENABLE (SJ4) must be left open circuit.
Resistor balance
To use resistor balance, please solder two identical resistors to R7 and R8, highlighted on the PCB
with the marking Resistive balance. Their landing pads can accommodate SMD 0603 or 5mm pitch
through hole resistors. Solderable jumpers marked as Active Balance POWER (SJ3) and Balance
output ENABLE (SJ4) must be left open circuit as shown on the left of figure 7.
CAP-XX recommends the maximum resistance for R7 and R8 to be 39KΩ. At higher temperatures
lower value resistors should be used.
Active OPAMP balance
R4, R5, IC2 and R6 is the active cell balancing sub circuit. IC2 TLV8801 is a low quiescent current
general purpose OPAMP, configured as a unity gain buffer. R4 and R5 set the reference voltage
for the buffer and R6 limits the OPAMP output current and guarantees op amp stability into a
capacitive load. To use the active balancing option resistors R7 and R8 must be removed or left
unpopulated and the solderable jumpers marked as Active Balance POWER (SJ3) and Balance
output ENABLE (SJ4) must be bridged with solder as shown on the right of figure 7. The quiescent
current from this circuit is ~750nA excluding the supercapacitor leakage current.
For more information regarding cell balancing, please refer to CAP-XX Application Note
AN1002_Cell balancing on our website.
Figure 7: cell balance options, Left- resistor balance, Right – active balance

User manual for APPEB1002 Revision 2.1, Oct 2019
General Purpose CAP-XX Supercapacitor Evaluation Board
© CAP-XX Pty Limited 2019 | Tel [phone] | www.cap-xx.com
Page 8of 8
Further Information
CAP-XX will be pleased to provide further information on the applications described here, and on
the use of supercapacitors in any application. Please use the contact details provided on the CAP-
XX web site (www.cap-xx.com).
This evaluation PCB can be purchased from the CAP-XX website, https://cap-xx-store.com/ or
contact [e-mail] .
This User Manual is available on the cap-XX web site. On the web site you may also find product
bulletins, datasheets, SPICE models, application white papers, application briefs and design-aid
calculator (http://cap-xx.com/resources/resources.htm).