®
January 16th, 2013
Document-No.: DB_PCapØ2-EVA-Kit_en V0.0
®PCapØ2
acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de
Publishe d by acam-me s se l e ctronic gmbh
©acam-messelectronic gmbh 2013
Disclaime r / Notes
“Preliminary” product information describes a product which is not in full production so
that full information about the product is not available yet. Therefore, acam -messelectronic
gmbh (“acam”) reserves the right to modify this product without notice. The information
provided by this data sheet is believed to be accurate and reliable. However, no
responsibility is assumed by acam for its use, nor for any infringements of patents or
other rights of third parties that may result from its use. The information is subject to
change without notice and is provided “as is” without warranty of any kind (expressed or
implied). ® is a registered trademark of acam. All other brand and product names
in this document are trademarks or service marks of their respective owners.
Support / Cont a ct
For a complete listing of Direct Sales, Distributor and Sales Representative contacts, visit
the acam web site at:
http://www.acam.de/sales/distributors/
For technical support you can contact the acam support team in the headquarters in
Germany or the Distributor in your country. The contact details of acam in Germany are:
support@acam.de or by phone +49-7244-74190
PCapØ2
acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de 1-1
Content
1 Introduction .............................................................................................. 1-2
1.1 General .............................................................................................. 1-2
1.2 Component List .................................................................................... 1-2
2 Connecting Capacitors and Resistors ............................................................. 2-4
2.1 Capacitance Measurement ..................................................................... 2-4
2.2 Temperature Measurement .................................................................... 2-5
2.3 Pulse Code Generation .......................................................................... 2-6
2.4 Motherboard ....................................................................................... 2-6
3 Miscellaneous ........................................................................................... 3-1
3.1 Literature Guide ................................................................................... 3-1
3.2 Document History ................................................................................ 3-2
4 Appendix .................................................................................................. 4-1
4.1 Schematics ......................................................................................... 4-1
4.2 Layout ................................................................................................ 4-3
®PCapØ2
1-2 acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de
1 Introduction
1.1 General
The PCapØ2-EVA-KIT evaluation system provides a complete system for generally
evaluating the PCapØ2 chip. It comprises of a main board, a plug-in module, a Windows
based evaluation software, assembler software and the PicoProg V2.0 programming
device. The PCapØ2 evaluation board is connected to the PC‘s USB interface through the
PicoProg V2.0 programming device.
The evaluation kit offers user friendly configurations for evaluating the PCapØ 2 single-chip
solution for capacitance measurement. This kit can be used to evaluate the capacitance
measurement, temperature measurement and the pulse generation capa bilities of the
PCapØ2 chip.
For a proper use of the evaluation system it is strongly recommended to refer to the
current data sheet of the PCapØ2 device. You can download these data sheets from
www.acam.de/download-center/picocap .
1.2 Component List
PCapØ1-MB Motherboard
PCapØ2-AD Plug-in module Based on PCapØ2-AD in QFN32 package
PicoProg V2.0 Programmer
High density DSUB15 cable Connecting the Evaluation board to the
programmer
USB cable Connects PicoProg V2.0 to the PC
Wall power supply unit 9 V
CD-ROM Includes software and data sheets
PCapØ2
acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de 1-3
Figure 1-1: Components of the evaluation kit
®PCapØ2
2-4 acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de
2 Connecting Capacitors and Resistors
This evaluation kit can be used for evaluating capacitance measurement by connecting capacitive
sensors. Further, it can be used for evaluating temperature measurement by connecting external
temperature sensitive resistors or for generating quasi analog voltage (pulse width/density
modulated) that is dependent on the sensor connected to the system.
Depending on the purpose of evaluation, a modification has to be made to the same plug-in
module. Following is a picture of the Mother board with the plug-in module.
Figure 2-1: The evaluation kit’s motherboard and plug-in module
The following sections describe the modifications for each application in detail.
2.1 Capacitance Measurement
For the purpose of evaluating the capacitance measurement
using PCapØ2, the plug-in module is pre-assembled with
ceramic capacitors to emulate capacitive sensors. These
capacitors, each 47pF in value, are connected to the 8
ports PC0 to PC7. They are connected as single sensors in
floating mode, i.e. each capacitor is connected between 2
ports, and hence there are 4 x 47pF on-board capacitors.
Please refer to section 3 of the PCapØ2 data sheet for
more information on how to connect capacitors to the chip.
The capacitor connected between ports PC0 and PC1 is
taken as the reference capacitor.
Figure 2-2: Details of the plug-in module
Ceramic capacitors
47 pF each
Reference
capacitor
47 pF
PCapØ2
acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de 2-5
In the process of evaluation, when you are comfortable with interpreting the measurement results
from the chip, these fixed capacitors can be replaced with the actual capacitive sensors of your
application.
If you want to connect your capacitive sensors in grounded mode, then GND points are provided
at the two ends of the module, where the sensor ground connections ought to be soldered.
The typical value of the capacitive sensors that can be connected to the evaluation kit lies in the
range of 30pF to 3.5nF. The reference capacitor should be in the same order of magnitude as
the sensor. Depending on the value of the sensor, the value of the internal resistor for performing
the measurement has to be selected. For the pre-assembled 47pF capacitors, an internal
discharge resistor of 180kOhm works well. See section 3 of the PCapØ2 data sheet on how to
select the value of the internal discharge resistor.
2.2 Temperature Measurement
Temperature measurement or other resistive tasks may also be of interest for the user of this kit.
The evaluation kit offers this possibility through the RDC (resistive-to-digital converter) ports. An
on-chip thermistor coupled with an on-chip temperature-stable reference resistor made of
polysilicon is sufficient for observing the temperature measurement capability of the PCapØ2 chip.
Figure 2-3: Temperature sensor connection pads
However, there is a possibility to connect the reference resistor and the thermistor externally to
the chip, too. In case of external resistors, the temperature-stable reference resistor ought to be
connected at port PT2REF on the plug-in module. The module allows you to connect the external
Port PT1 for 2nd external temperature sensor
(not supported by the standard firmware)
Port PT0 for external temperature sensor
Port PT2 for external reference resistor
33 nF COG
®PCapØ2
2-6 acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de
thermistor, e.g. a PT1000 sensor at port PT0 (or PT1, not supported yet by the standard
firmware).
In any case, for the temperature measurement, an external capacitor 33 nF C0G has to be
connected to the chip; it is already pre-assembled on board.
2.3 Pulse Code Generation
Any of the capacitance or temperature measurement results from the PCapØ2 chip can be given
out as a pulse width modulated or pulse density modulated signal. This output can be filtered to
generate an analog output signal that can be used for further controlling.
These pulse width or pulse density codes can be generated at Ports PG0, PG1, PG2 or PG3.
Since ports PG0 and PG1 are used for the SPI Interface in the module, the hardware allows to get
a valid pulse width/density modulated signal on PG2 or PG3. However, when I2C communication
mode is used the pulsed signals can be optionally obtained on the ports PG0 and PG1.
Figure 2-4: General purpose interface ports PG0 to PG3
2.4 Motherboard
The motherboard connects to the PicoProg V2.0 programmer. It serves the various power
options. It can be powered via wall plug supply, the voltage being set from 1.8V to 4.5V by
jumpers. Further, it supports a battery power option. Power present is indicated by a green LED.
PG2
PG3
PG0
PG1
PCapØ2
acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de 2-7
There is a jumper ‘Current’ on the mother board. The current consumption of the PCapØ2 chip
during operation can be directly measured from these jumper terminals.
All interface signals and general purpose I/O signals can be monitored by means of a separate
jumper.
®PCapØ2
2-2 acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de
PCapØ2
acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de 3-1
3 Miscellaneous
3.1 Literature Guide
Title
Document-No
PCapØ2A
Single-chip Solution for Capacitance Measurement
Volume 1: General data and front-end description
DB_PCap02A_Vol1_en.pdf
PCapØ2Ax-DSP
Single-chip Solution for Capacitance Measurement
Volume 2: Digital Signal Processor
DB_PCap02A_Vol2_en.pdf
PCapØ2-EVA-Kit
Evaluation System for PCapØ2
DB_PCap02-EVA-Kit_en.pdf
PCapØ2plus
Evaluation Software for PICOCAP Devices
DB_PCap02plus_en.pdf
PCap Assembler
Assembler Software for PICOCAP Devices
DB_PCap-Assembler_en.pdf
Title
Document-No
Title
Document-No
The latest versions of the available documents can be downloaded from the acam website
at:
http://www.acam.de/download-center/picocap
®PCapØ2
3-2 acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de
3.2 Document History
16.01.2013 First release
PCapØ2
acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de 4-1
4 Appendix
4.1 Schematics
Figure 4-1: Motherboard schematics
®PCapØ2
4-2 acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de
Figure 4-2: PCa02 AD module schematics
PCapØ2
acam messelectronic gmbh - Friedrich-List-Str.4 - 76297 Stutensee - Germany - www.acam.de 4-3
4.2 Layout
Figure 4-3: PCa02 AD module layout
