GestIC Design Guide

GestIC® Design Guide
 2013-2016 Microchip Technology Inc.
DS40001716C
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DS40001716C-page 2
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Microchip Technology Inc. in other countries.
GestIC is a registered trademarks of Microchip Technology
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All other trademarks mentioned herein are property of their
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© 2013-2016, Microchip Technology Incorporated, Printed in
the U.S.A., All Rights Reserved.
ISBN: 978-1-5224-0477-4
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Table of Contents
Preface ........................................................................................................................... 5
Chapter 1. GestIC® Design-In
1.1 Introduction ................................................................................................... 11
Chapter 2. GestIC® Sensor
2.1 Introduction ................................................................................................... 13
2.2 Decision for a sensor design ........................................................................ 14
2.3 GestIC Sensor Characteristics ..................................................................... 15
Chapter 3. GestIC® Standard Electrode Design
3.1 General Design Rules .................................................................................. 17
3.1.1 Sensor Outline ........................................................................................... 17
3.1.2 Rx Electrodes ............................................................................................ 17
3.1.3 Tx Electrodes ............................................................................................ 18
3.1.4 Chip Placement and Rx Feeding Lines ..................................................... 19
3.1.5 Layer Stack ............................................................................................... 20
Chapter 4. Electrode Design for Battery-Operated Systems
4.1 What is battery operation? ........................................................................... 23
4.1.1 Electrode Design ....................................................................................... 24
4.1.2 Parameterization ....................................................................................... 27
Chapter 5. Boosted Electrode Design
5.1 Circuitry for Tx Boost .................................................................................... 29
5.2 Electrode Design for 3D only systems ......................................................... 30
5.2.1 Rx electrodes ............................................................................................ 30
5.2.2 Tx electrodes ............................................................................................. 30
5.2.3 Rx Feeding Lines ...................................................................................... 31
5.2.4 Chip Placement ......................................................................................... 31
5.2.5 Layer Stack ............................................................................................... 31
5.2.6 Optimization of Rx-Tx Coupling ................................................................. 31
Chapter 6. Sensor Integration and Common Mistakes
6.1 GestIC® and Ground .................................................................................... 33
6.2 Sensor Layout on a PCB .............................................................................. 34
6.3 Common Mistakes of GestIC Electrode Design ........................................... 35
Appendix A. GestIC® Design-In Checklist
Appendix B. Reference Circuitry for MGC3130
Appendix C. Reference Circuitry for MGC3030
Appendix D. Reference Circuitry for MGC3130 Boosted
Appendix E. GestIC® Equivalent Circuitry and Capacitance Design Goals
Appendix F. GestIC® Performance Evaluation
 2013-2016 Microchip Technology Inc.
DS40001716C-page 3
GestIC® Design Guide
F.1 Analog Front End (AFE) ............................................................................... 47
F.2 Signal Deviation ........................................................................................... 48
F.3 Noise values ................................................................................................. 49
F.4 Recognition Range ....................................................................................... 50
Appendix G. GestIC® Hardware References
G.1 GestIC® Hardware References ................................................................... 51
Worldwide Sales and Service .....................................................................................53
DS40001716C-page 4
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Preface
NOTICE TO CUSTOMERS
All documentation becomes dated, and this manual is no exception. Microchip tools and
documentation are constantly evolving to meet customer needs, so some actual dialogs
and/or tool descriptions may differ from those in this document. Please refer to our website
(www.microchip.com) to obtain the latest documentation available.
Documents are identified with a “DS” number. This number is located on the bottom of each
page, in front of the page number. The numbering convention for the DS number is
“DSXXXXXA”, where “XXXXX” is the document number and “A” is the revision level of the
document.
For the most up-to-date information on development tools, see the MPLAB® IDE online help.
Select the Help menu, and then Topics to open a list of available online help files.
INTRODUCTION
This chapter contains general information that will be useful to know before using the
GestIC® Design Guide. Items discussed in this chapter include:
•
•
•
•
•
•
•
•
Document Layout
Conventions Used in this Guide
Warranty Registration
Recommended Reading
The Microchip Website
Development Systems Customer Change Notification Service
Customer Support
Revision History
 2013-2016 Microchip Technology Inc.
DS40001716C-page 5
GestIC® Design Guide
DOCUMENT LAYOUT
This document describes how to use the GestIC® Design Guide as a development tool
to emulate and debug firmware on a target board, as well as how to program devices.
The document is organized as follows:
• Chapter 1. “GestIC® Design-In” – Describes the recommended design-in
process got GestIC® sensors.
• Chapter 2. “GestIC® Sensor” – Introduces GestIC® sensor designs, expected
performance and characteristic values.
• Chapter 3. “GestIC® Standard Electrode Design” – Describes the rules to
design GestIC® standard electrodes.
• Chapter 4. “Electrode Design for Battery-Operated Systems” – Describes the
rules to design electrodes for battery-operated systems.
• Chapter 5. “Boosted Electrode Design” – Describes the rules to design
boosted GestIC® systems.
• Chapter 6. “Sensor Integration and Common Mistakes” – Presents tips for
sensor integration and a list of common mistakes.
• Appendix A. “GestIC® Design-In Checklist” – Describes the GestIC® design-in
checklist – worksheet for customers.
• Appendix B. “Reference Circuitry for MGC3130” – Provides reference circuitry
for MGC3130.
• Appendix C. “Reference Circuitry for MGC3030” – Provides reference circuitry
for MGC3030.
• Appendix D. “Reference Circuitry for MGC3130 Boosted” – Provides
reference circuitry for MGC3130 boosted.
• Appendix E. “GestIC® Equivalent Circuitry and Capacitance Design Goals”
– Provides the GestIC® equivalent circuitry and capacitance design goals.
• Appendix F. “GestIC® Performance Evaluation” – Provides details about
performance evaluation and reference values.
• Appendix G. “GestIC® Hardware References” – Provides details on the
GestIC® hardware references package which contains design sources for
electrodes and demos.
DS40001716C-page 6
 2013-2016 Microchip Technology Inc.
Preface
CONVENTIONS USED IN THIS GUIDE
This manual uses the following documentation conventions:
DOCUMENTATION CONVENTIONS
Description
Arial font:
Italic characters
Initial caps
Quotes
Underlined, italic text with
right angle bracket
Bold characters
N‘Rnnnn
Text in angle brackets < >
Courier New font:
Plain Courier New
Represents
Referenced books
Emphasized text
A window
A dialog
A menu selection
A field name in a window or
dialog
A menu path
MPLAB® IDE User’s Guide
...is the only compiler...
the Output window
the Settings dialog
select Enable Programmer
“Save project before build”
A dialog button
A tab
A number in verilog format,
where N is the total number of
digits, R is the radix and n is a
digit.
A key on the keyboard
Click OK
Click the Power tab
4‘b0010, 2‘hF1
Italic Courier New
Sample source code
Filenames
File paths
Keywords
Command-line options
Bit values
Constants
A variable argument
Square brackets [ ]
Optional arguments
Curly brackets and pipe
character: { | }
Ellipses...
Choice of mutually exclusive
arguments; an OR selection
Replaces repeated text
Represents code supplied by
user
 2013-2016 Microchip Technology Inc.
Examples
File>Save
Press <Enter>, <F1>
#define START
autoexec.bat
c:\mcc18\h
_asm, _endasm, static
-Opa+, -Opa0, 1
0xFF, ‘A’
file.o, where file can be
any valid filename
mcc18 [options] file
[options]
errorlevel {0|1}
var_name [,
var_name...]
void main (void)
{ ...
}
DS40001716C-page 7
GestIC® Design Guide
WARRANTY REGISTRATION
Please complete the enclosed Warranty Registration Card and mail it promptly.
Sending in the Warranty Registration Card entitles users to receive new product
updates. Interim software releases are available at the Microchip website.
RECOMMENDED READING
This user’s guide describes how to design a GestIC® sensor. Other useful documents
are listed below. The following Microchip documents are available and recommended
as supplemental reference resources.
MGC 3030/3130 3D Gesture Controller Data Sheet (DS40001667)
This data sheet provides information about the MGC3030/3130 3D Gesture Controller.
GestIC® Hardware References
This is a collection of reference designs for electrodes and demonstrators to be used
for hardware integration.
MGC3030/3130 GestIC® Library Interface Description (DS40001718)
This document is the interface description of the MGC3XXX and provides a description
and the complete reference of I2C messages.
MGC3030/3130 Software Development Kit (SDK)
The Software development kit contains GestIC API and C reference code for applications for Windows, Linux, and Embedded controllers.
MGC3030/3130 PIC18 Host Reference Code
The PIC18 reference code contains an easy example for MGC3XXX message decoding on PIC18F14K50 (Hillstar I2C to USB bridge)
Aurea Graphical User Interface User’s Guide (DS40001681)
Aurea Software Package
The Aurea package contains all relevant system software and documentation to operate and parameterize MGC3XXX devices. An integrated online help give the details
about MGC3XXX parameterization.
DS40001716C-page 8
 2013-2016 Microchip Technology Inc.
Preface
THE MICROCHIP WEBSITE
Microchip provides online support via our website at www.microchip.com. This website
is used as a means to make files and information easily available to customers. Accessible by using your favorite Internet browser, the website contains the following information:
• Product Support – Data sheets and errata, application notes and sample
programs, design resources, user’s guides and hardware support documents,
latest software releases and archived software
• General Technical Support – Frequently Asked Questions (FAQs), technical
support requests, online discussion groups, Microchip consultant program
member listing
• Business of Microchip – Product selector and ordering guides, latest Microchip
press releases, listing of seminars and events, listings of Microchip sales offices,
distributors and factory representatives
DEVELOPMENT SYSTEMS CUSTOMER CHANGE NOTIFICATION SERVICE
Microchip’s customer notification service helps keep customers current on Microchip
products. Subscribers will receive e-mail notification whenever there are changes,
updates, revisions or errata related to a specified product family or development tool of
interest.
To register, access the Microchip website at www.microchip.com, click on Customer
Change Notification and follow the registration instructions.
The Development Systems product group categories are:
• Compilers – The latest information on Microchip C compilers, assemblers, linkers
and other language tools. These include all MPLAB C compilers; all MPLAB
assemblers (including MPASM™ assembler); all MPLAB linkers (including
MPLINK™ object linker); and all MPLAB librarians (including MPLIB™ object
librarian).
• Emulators – The latest information on Microchip in-circuit emulators.This
includes the MPLAB REAL ICE™ and MPLAB ICE 2000 in-circuit emulators.
• In-Circuit Debuggers – The latest information on the Microchip in-circuit
debuggers. This includes MPLAB ICD 3 in-circuit debuggers and PICkit™ 3
debug express.
• MPLAB® IDE – The latest information on Microchip MPLAB IDE, the Windows®
Integrated Development Environment for development systems tools. This list is
focused on the MPLAB IDE, MPLAB IDE Project Manager, MPLAB Editor and
MPLAB SIM simulator, as well as general editing and debugging features.
• Programmers – The latest information on Microchip programmers. These include
production programmers such as MPLAB REAL ICE in-circuit emulator, MPLAB
ICD 3 in-circuit debugger and MPLAB PM3 device programmers. Also included
are nonproduction development programmers such as PICSTART® Plus and
PICkit 2 and 3.
 2013-2016 Microchip Technology Inc.
DS40001716C-page 9
GestIC® Design Guide
CUSTOMER SUPPORT
Users of Microchip products can receive assistance through several channels:
•
•
•
•
Distributor or Representative
Local Sales Office
Field Application Engineer (FAE)
Technical Support
Customers should contact their distributor, representative or field application engineer
(FAE) for support. Local sales offices are also available to help customers. A listing of
sales offices and locations is included in the back of this document.
Technical support is available through the website at:
http://www.microchip.com/support.
REVISION HISTORY
Revision A (August 2013)
This is the initial release of this document.
Revision B (January 2015)
Changed document title; Added note and updated titles in the Recommended Reading
section; Other minor corrections.
Revision C (April 2016)
Added latest design rules for GestIC standard designs; Added battery operated
systems information; Added boosted systems information. Updated the Recommended Reading section; Other corrections.
DS40001716C-page 10
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Chapter 1. GestIC® Design-In
1.1
INTRODUCTION
The MGC3XXX gesture controllers based on Microchip’s GestIC® technology offer a
fully integrated 3D gesture solution for numerous commercial, industrial, medical and
automotive applications. This design guide explains the GestIC electrode design rules,
provides examples for good sensor designs and deals with potential pitfalls.
The design-in process of a GestIC system has five steps, as shown as an overview in
Figure 1-1.
FIGURE 1-1:
GESTIC® DESIGN-IN PROCESS
1. Step 1 reviews the entire 3D application before starting the design. The following
points should be known:
- Use cases of the input device
- Sensor range expectation
- Required 3D sensor features
- Available space for the sensor
- Battery operation
- Combination with Microchip 2D (touch controller) or 1D (buttons) solutions
When this information is available, a first electrode design can be drawn.
2. Step 2 is the electrode design within the given application boundaries. At this
point the following information is required:
- Mechanical construction of the device (dimensions, placement of building
blocks, metal/conductive parts)
- Electrical circuitry (block diagram, power supply, host controller, peripherals,
interconnection)
- Connection to ground (GND)
- Possible noise sources within the system
3. Steps 3 and 4 are integration steps for the sensor into the application’s hardware
and software structure, based on the information provided at step 2. Details such
as schematics and software architecture of the complete system may be
required.
4. After these steps, it is recommended to build a sensor prototype and
parameterize it for the target application.
5. Step 5 handles the tuning of GestIC firmware parameters.
This Electrode Design Guide covers the GestIC electrode design (steps 1 and 2) and the
basics of hardware integration (steps 3 and 4).
 2013-2016 Microchip Technology Inc.
DS40001716C-page 11
GestIC® Design Guide
TABLE 1-1:
DESIGN-IN REFERENCE DOCUMENTATION
Design-In Step
1. Idea
2. Electrode Design
3. Hardware Integration
Reference Documentation
MGC 3030/3130 3D Gesture Controller Data Sheet (DS40001667)
GestIC® Design Guide (DS40001716)
GestIC® Hardware References (Collection of reference designs for
electrodes and demonstrators)
4. Software Integration MGC3030/3130 GestIC® Library Interface Description
(DS40001718)
MGC3030/3130 Software Development Kit (SDK)
MGC3030/3130 PIC18 Host Reference Code
5. Parameterization
Note:
Aurea Graphical User Interface User’s Guide (DS40001681)
Aurea Software Package
All referenced guides, reference designs, and drivers can be downloaded from
http://www.microchip.com/gesticresources.
The GestIC design-in checklist in Appendix A. “GestIC® Design-In Checklist” will help
the designer to collect the needed information for the sensor design.
DS40001716C-page 12
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Chapter 2. GestIC® Sensor
2.1
INTRODUCTION
A 3D GestIC® sensor is the combination of a gesture controller (MGC3XXX) and a set
of sensor electrodes.
FIGURE 2-1:
GESTIC® SENSOR
MGC3XXX communicates with a host controller via I2C or by gesture mapping to I/O
pins (GesturePort). For details, refer to the MGC3030/3130 3D Tracking and Gesture
Controller Data Sheet (DS40001667). It is possible to combine a 3D GestIC sensor with
Microchip’s 1D and 2D solutions, sharing the same electrode structures. This is
supported by MGC3130 and MGC3140.
The GestIC electrodes consist of:
• 4 or 5 Receive electrodes (Rx) connected to Rx 0-4 pins of MGC3XXX
• 1 Transmit electrode (Tx) connected to the Tx pin of MGC3XXX
• Isolation between Rx and Tx
Rx and Tx are made of any conductive material such as copper, metal mesh, indium
tin oxide (ITO) or similar. The isolation between the electrodes can be any material
which is non-conductive (PCB, glass, PET, etc.). An optional cover layer on top of the
electrode must be non-conductive as well.
There are two different sensor designs supported:
1. The Standard sensor (Tx amplitude = 2.85V) is used in small or medium-sized
devices and it is mandatory for devices having a weak connection to earth
ground (battery operated).
 2013-2016 Microchip Technology Inc.
DS40001716C-page 13
GestIC® Design Guide
2. Boosted sensors (Tx amplitude = 5-18V) allow larger sensor sizes and
recognition ranges. That is necessary in particular in combination with 2D touch
sensors.
Figure 2-2 shows the structure of the two sensor designs.
GestIC® ELECTRODE
FIGURE 2-2:
GestIC® Standard Sensor
GestIC® Boosted Sensor
Cover
(non conductive)
Rx Electrodes
es
Isolation
Tx Electrode
Ground (GND)
The reference circuitry for each design is shown in Appendix B. “Reference Circuitry
for MGC3130”.
2.2
DECISION FOR A SENSOR DESIGN
The decision for a sensor design depends on the application, on the available space in
the customer’s system, and on the sensor environment. Devices which are connected
to ground and have a certain size may prefer a boosted electrode. Non-grounded
sensor systems (battery operated) are based on standard electrodes.
Figure 2-3 shows an overview of expected gesture recognition ranges of GestIC
sensors, Figure 2-4 provides a decision matrix which helps to choose the right design
for a given application.
FIGURE 2-3:
EXPECTED GESTURE RECOGNITION RANGE VS. SENSOR
SIZE AND TYPE
Maximum Recognition range
mm
200
Boosted, grounded
100
Standard, grounded
Standard, Battery Operation
100
200
mm
Sensor Size
DS40001716C-page 14
 2013-2016 Microchip Technology Inc.
GestIC® Sensor
FIGURE 2-4:
DECISION MATRIX
20 ..
140mm
Target Sensor Size
50 ..
>200mm
Standard
electrode
Battery
Operation*
NO
External
electrical
noise
Low Medium
Chapter 3
2 Layer
2.3
Boosted
Electrode
YES
Battery
Operation*
NO
YES
High
Chapter 3
3 Layer
Chapter 4**
3 Layer
Not
applicable
Chapter 5**
2 Layer
Note 1:
Battery operation refers to systems which are battery-driven and have a weak connection to
ground. Details in Chapter 4.
2:
The general design rules for GestIC® electrodes are explained in Chapter 3 and are valid for
battery-optimized and boosted electrodes as well.
GESTIC SENSOR CHARACTERISTICS
A number of definitions are used to describe and characterize a GestIC sensor, as
shown in Figure 2-5.
The Sensing Space is the space above the sensor area where it’s sensitive to the
human hand. The sensor area is measured between the inner edges of the Rx
electrodes. The height of the sensing space is determined by the maximum recognition
range of the sensor.
GestIC technology utilizes the electrical field to track hand movements. The detection
method recognizes the electrical center of mass of the human hand, and it is able to
track a single point inside the sensing space of a GestIC sensor over time.
The Sensor Recognition Range is defined as the maximum distance of the human
hand from the sensor surface, which allows to track the position and to recognize
gestures. Depending on the feature, different recognition ranges can be defined.
FIGURE 2-5:
GESTIC® SENSOR DEFINITIONS
Hold
Recognition Range
 2013-2016 Microchip Technology Inc.
b cm
a cm
Flick
Recognition Range
DS40001716C-page 15
GestIC® Design Guide
NOTES:
DS40001716C-page 16
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Chapter 3. GestIC® Standard Electrode Design
3.1
GENERAL DESIGN RULES
3.1.1
Sensor Outline
GestIC®
technology can work with a wide range of sensor sizes and shapes. The
sensor outline follows the available space in the product. The sensor shape can be
square, rectangular, circular or oval, but it should not exceed a 1:3 ratio, as shown in
Figure 3-1.
FIGURE 3-1:
SENSOR OUTLINE
square
OK
circle
OK
oval
OK
ratio 1:3
OK
GestIC standard electrodes work within the following recommended dimensions:
• Maximum size = 140 x 140 mm/diameter 140 mm
• Minimum size = 20 x 20 mm/diameter 20 mm
Using the Tx Boosted sensor, the maximum size increases to 200 x 200 mm and
higher. Refer to Chapter 5. “Boosted Electrode Design”.
3.1.2
Rx Electrodes
Rx electrodes are placed inside the top layer of the sensor. The minimum GestIC
system consists of four Rx electrodes aligned as a rectangular frame along the edges
of a sensor board. They are named after the four cardinal directions: North, West,
South, and East.
Their length should be laid out as long as the device size allows. It is good practice to
balance the length of the two vertical and the two horizontal electrodes. If the
recognition range should be symmetrical in both directions, the electrode design should
be symmetrical. The recommended distance between the Rx electrodes is 1.5 mm, as
indicated in Figure 3-2.
FIGURE 3-2:
ELECTRODE SHAPE
equal length for all
Rx electrodes
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DS40001716C-page 17
GestIC® Design Guide
The Rx electrodes’ width is 4 to 7% of their length. Wider electrodes have a better
exposure to the human hand and should be preferred.
It is also possible to further increase the Rx electrodes’ area. That will limit the gesture
recognition range, but the higher capacitance to the hand brings advantages in weakly
grounded systems. Thus, such an extension has been consequently applied for battery
powered systems. For further details, refer to Chapter 4. “Electrode Design for
Battery-Operated Systems”.
FIGURE 3-3:
RX ELECTRODE WIDTH
Battery optimized
Standard widthŝƐ
5Ͳ7%
from length
Increased
width
The Microchip gesture controllers support a fifth electrode, as shown in Figure 3-4. It
functions either as a center electrode to establish a center touch, or as a structure to
build a sensor ring for approach/proximity detection, or an additional touch button.
A center electrode is usually stretched over the area inside the frame electrodes, and
it is recommended to be cross-hatched (5-10% hatching, not smaller than the finger
pitch). Alternative structures can be placed outside the sensor area, but need to be laid
out over a Tx area. For further information on the rules for Tx, refer to
Section 3.1.3 “Tx Electrodes”.
FIGURE 3-4:
USAGE OF FIFTH ELECTRODE
Alternative:
Button
Center 5Ͳ10%
hatched
3.1.3
Alternative:
Proximity
Tx Electrodes
The GestIC Tx electrode emits an electrical field and it is located below the Rx
electrodes. It shields Rx electrodes and feeding lines from the human body and from
electrical disturbers on the back of the sensor.
In order to improve shielding, it is recommended to overlap all Rx structures with Tx.
1-2 mm is the minimum overlapping value, and the optimum value is 50-100% of the
Rx electrodes width. The same rule applies when the electrode layout has cutouts,
holes, or if the center area is completely cut out (GestIC Ring Sensor).
DS40001716C-page 18
 2013-2016 Microchip Technology Inc.
GestIC® Standard Electrode Design
FIGURE 3-5:
TX ELECTRODE
overlap
overlap
overlap
overlap
Full Tx
Hatched Tx
to keep
CTxGND > 1 nF
Tx with Cutout
or ring design
When the capacitive load of Tx (CTXGND) exceeds MGC3XXX’s driving capability of
1 nF, the Tx electrode may be cross-hatched. If that is not sufficient, the Tx driving
strength can be increased using an external operational amplifier, such as a voltage
follower. Refer to Section 3.1.5 “Layer Stack” for more details.
For best performance and stability it is preferred that the Tx electrode covers the
complete area of the sensor. A ring design, as shown in Figure 3-5, is prone to external
noise. If the design includes a larger GND area inside the ring, recognition range will
decrease. That includes a possible GestIC sensor design around a TFT display. If
GestIC should be combined with a display, it is recommended to design transparent
electrodes and place them on top of the display. Refer to Chapter 5. “Boosted
Electrode Design” for more information.
3.1.4
Chip Placement and Rx Feeding Lines
The MGC3XXX device has to be placed as close as possible to the GestIC electrodes.
A good way to do this is to integrate the chip directly on the sensor board, e.g., on the
back side. The MGC3XXX circuitry should be away from the user’s common approach
direction.
The connection between Rx electrodes and the input pins of the gesture controller must
be handled with great care, as the Rx feeding lines are sensitive to the human hand
and to environmental noise in the same way Rx electrodes are. That’s why they should
be routed as short as possible and kept away from all external influences.
The following requirements should be met:
•
•
•
•
•
Keep as thin and short as possible (width 0.1-0.15 mm)
Route inside the sensor area
Keep away from analog and digital sources
Keep ground away from Rx electrodes and feeding lines
Shield with Tx (distance to Tx > 0.15 mm)
Note:
Rx feeding lines ought to be routed to the nearest Rx pin of MGC3XXX and
should not cross each other. The logical assignment between electrode and
Rx pin can be done later during the AFE parameterization.
 2013-2016 Microchip Technology Inc.
DS40001716C-page 19
GestIC® Design Guide
Figure 3-6 shows three possible layouts for Rx feeding lines. In the first two examples,
the feeding lines are routed in the Tx layer, while the third example shows a possibility
to route them in the top layer, e.g., if the center area is transparent.
FIGURE 3-6:
CHIP PLACEMENT AND RX FEEDING LINES – TOP VIEW
>1mm
Routed in
top layer
Routed in bottom layer,
embedded in Tx
Figure 3-7 represents the rear side view of the three examples.
FIGURE 3-7:
CHIP PLACEMENT AND RX FEEDING LINES – BOTTOM
VIEW
Rx overlapped
by Tx, 1Ͳ2mm
Rx feeding lines routed in
Tx, distance to Tx 0͘15mm
As seen in these examples, the gesture controller is recommended to be placed on the
same board as the sensor. It is, however, possible to connect the Rx electrodes via
connector to the MGC3XXX device on a different PCB. In this case, the connection
must be mechanically fixed and any moving of the feeding lines during sensor
operation has to be avoided. The connection via board-to-board connector is
recommended as opposed to using cables or flexible structures, unless they are
directly glued onto the PCBs and shielded by Tx.
3.1.5
Layer Stack
The GestIC sensor is built in a two layer stack, Rx on top and Tx underneath Rx. The
optimum distance between Rx and Tx (d) depends from the relative permeability of the
isolation material between the two layers, as shown in Equation 3-1.
EQUATION 3-1:
THICKNESS CALCULATION
r
d  ---5
DS40001716C-page 20
 2013-2016 Microchip Technology Inc.
GestIC® Standard Electrode Design
For the PCB material FR4 (εr = 5), the thickness is d > 1 mm.The sensor signals will
increase when the thickness increases: 1.5-2 mm will significantly improve the
performance. A thickness beyond 2 mm is seen as not practical and is the object of
future development. If the thickness is lower than 1 mm, the performance will drop.
Examples for different materials are given in Figure 3-8.
FIGURE 3-8:
LAYER STACK
d > 1.2 mm
d > 1 mm
d > 0.6 mm
εr = 3
εr = 5
Plastic
PCB (FR4)
εr = 6
Glass
The design of a two-layer electrode is simple, as shown in Figure 3-9. It is
recommended to lay out the top layer according to the rules in Section 3.1.2 “Rx
Electrodes”, and add the Tx layer as a full copper area. The overlapping rules from
Section 3.1.3 “Tx Electrodes” and the thickness rules mentioned before apply.
ELECTRODE LAYER STACK – TWO LAYERS
PCB:
> 1mm
FIGURE 3-9:
Rx Center
Rx South
Rx East
Rx West
Rx North
Rx
Conductive layer
Isolation
Conductive layer
Tx
Tx
An additional GND layer can be added to the layer stack. In battery-operated devices
this is mandatory (refer to Chapter 4. “Electrode Design for Battery-Operated
Systems”). In earth grounded systems it is optional and it depends on the
environment. The GND layer adds stability, noise robustness, and shield sensitivity
from the backside of the sensor at the cost of 10-20% lower range. The layer stack is
shown in Figure 3-10.
 2013-2016 Microchip Technology Inc.
DS40001716C-page 21
GestIC® Design Guide
FIGURE 3-10:
ELECTRODE LAYER STACK – THREE LAYERS
Tx
Rx Center
Rx East
Rx West
Rx North
Tx
GND
PCB:
> 1mm
Rx South
Rx
Conductive layer (Rx)
Isolation
Conductive layer (Tx)
Isolation
GND layer
Tx
PCB:
> 0͘5mm
GND
One additional requirement must be fulfilled: the capacitance between Tx and GND
must not exceed the MGC3XXX’s Tx driving capability of 1 nF, which is indicated in
Figure 3-11. An estimate of the capacitance can be done using the formula of the plate
capacitor, shown in Equation 3-2.
FIGURE 3-11:
ELECTRODE LAYER STACK – CAPACITANCE TX-GND
A
Tx
d
GND
EQUATION 3-2:
CAPACITANCE ESTIMATION
A
C =  0   r  --d
If the calculated capacitance is in the range of 1 nF or higher, special measures must
be taken to reduce it. The following options are recommended:
• Increase distance between Tx and GND
• Decrease relative permeability of the isolation layer (choose different material)
• Cross-hatch the Tx area – a good value is to cover of 50-60% with copper
If this is not possible, an external Tx driver (voltage follower) can be used. The circuitry
is shown in Figure 3-12.
FIGURE 3-12:
TX DRIVER
MGC3yyy
VCC
Tx pin
Tx
Electrode
+
-
GND
e.g. MCP6H91
DS40001716C-page 22
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Chapter 4. Electrode Design for Battery-Operated Systems
4.1
WHAT IS BATTERY OPERATION?
If the gesture-controlled electric device is battery-operated, it is often not sufficiently
connected to ground to maintain the loop to the human hand.
Two main effects can be observed:
• Low sensor signals
• Signals decrease when the hand approaches instead of increasing
The severity of these effects depend on the actual capacitance of the sensor to earth
ground and the sensor design and size. The result can be a low sensor performance
and requires adaptations of the electrode design which are described below.
The following figures illustrate the dependency from the ground capacitance.
Figure 4-1 shows a sensor in three different grounding conditions: grounded via USB,
battery-operated with a short wire connected to system ground, and just
battery-operated without any wire or connection to GND. The performance of this
sensor was tested on a wooden table. Figure 4-2 shows the corresponding flick
recognition ranges.
FIGURE 4-1:
TEST CASES FOR EARTH GROUND COUPLING
Grounded via USB
FIGURE 4-2:
Battery with wire
Battery no wire
FLICK RECOGNITION RANGE DEPENDING ON EARTH
GROUND COUPLING
8
Range in cm
7
6
5
4
3
2
1
0
Grounded
 2013-2016 Microchip Technology Inc.
Battery with wire Battery no wire
DS40001716C-page 23
GestIC® Design Guide
The tests show that the flick recognition range is reduced to 50% if the sensor does not
have any connection to earth ground. It becomes obvious that the first countermeasure
is to increase the coupling of the device to earth ground. Just a wire connected to the
system ground results in a much higher range.
Applications with metallic parts and internal wiring (chassis, loudspeakers) benefit from
that effect. If the presence of metal in a device is large enough (e.g., laptops), it can be
considered as ‘grounded’, and design rules in Chapter 3. “GestIC® Standard
Electrode Design” and Chapter 5. “Boosted Electrode Design” apply.
For small battery-driven devices with a few metallic parts, such as remote controls,
Bluetooth® speakers, or light controls, the following additional design rules apply:
1. Increase Rx electrode area: better exposure to hand
2. Hide Tx behind Rx: do not expose Tx to hand/avoid transmission
3. Increase coupling to earth ground: maximize system ground (4-layer design
mandatory)
4. Electrodes > 8-10 cm: increase coupling between Rx electrodes to compensate
decreasing sensor signals
4.1.1
Electrode Design
These additional rules result in designs with increased Rx area as shown in Figure 4-3.
The principle sensor design is the same as introduced in 3.1 “General Design Rules”,
only the Rx electrode is changed to meet the additional design rules. Requirements for
layer stack-up, Tx electrode, chip placement and feeding lines remain the same.
Rx North
Rx West
BATTERY-OPTIMIZED SENSOR DESIGN
Tx
Rx East
FIGURE 4-3:
Tx
GND
PCB:
> 1mm
Rx South
Rx
Conductive layer (Rx)
Isolation
Conductive layer (Tx)
Isolation
GND layer
GND
PCB:
> 0͘5mm
Tx
Compared to standard electrode design, battery-optimized electrodes achieve a lower
flick recognition range (compare with Figure 2-3).
Depending on electrode size and system architecture, the following variants of Rx
electrode layout are recommended:
1. Setup A
Setup A, shown in Figure 4-4, is represented by small devices which consist of a single
PCB and have a size of < 8 cm. This includes battery-driven light switches or remote
controls.
DS40001716C-page 24
 2013-2016 Microchip Technology Inc.
Electrode Design for Battery-Operated Systems
FIGURE 4-4:
TYPICAL SETUP A DEVICE
Sensor PCB
Batteries
Setup A devices need to be optimized for a maximum signal deviation and do not have
a significant decrease of their sensor signals when a hand approaches. Thus, the
optimization is to increase the Rx electrode area as shown in Figure 4-5.
SENSOR DESIGN FOR SETUP A DEVICES
< 8cm
FIGURE 4-5:
A 3-layer design is mandatory, for the rest of the design the general rules of Chapter
3. “GestIC® Standard Electrode Design” apply.
Note:
It is recommended that the capacitance between Tx and GND (CTXGND) is
smaller than 1 nF. For details, refer to Section 3.1.5 “Layer Stack”.
2. Setup B
Setup B is represented by devices which consist of a single PCB and a size between
8 and 14 cm.
These devices can be table top devices for home automation or wireless control units
for home appliances.
Setup B devices need to be optimized for a maximum signal deviation, but due to their
size, they have a significant decrease of their sensor signals when a hand approaches.
Thus, the optimization includes increased Rx electrodes and a higher coupling
between opposite Rx electrodes.
A recommended way is to add extensions to the electrodes which go inside the
opposite electrodes, as shown in Figure 4-6.
FIGURE 4-6:
SENSOR DESIGN FOR SETUP B DEVICES
Increase Rx coupling by
direct signal coupling
 2013-2016 Microchip Technology Inc.
DS40001716C-page 25
GestIC® Design Guide
If such design is required, contact Microchip.
3. Setup C
Setup C is represented by devices which include two or more modules that are
distributed in a certain volume and are interconnected via cables. The actual GestIC®
sensor size is not crucial for such systems because the system ground is distributed
over the complete volume and establishes a minimum connection to earth ground.
Typical Setup C devices, shown in Figure 4-7, are Bluetooth speakers (sensor PCB,
main PCB, speaker), and toys (sensor PCB, main PCB, motors).
FIGURE 4-7:
TYPICAL SETUP C DEVICES
Sensor PCB
Cable
Main PCB
Batteries
Setup C sensors need care for a maximum signal deviation only. Thus, the optimization
is to increase the Rx electrode area only as shown in Figure 4-8.
FIGURE 4-8:
SENSOR DESIGN FOR SETUP C DEVICES
Electrode width:
20% from length
A 3-layer design is recommended, for the rest of the design the general rules of
Section 3.1 “General Design Rules” apply.
DS40001716C-page 26
 2013-2016 Microchip Technology Inc.
Electrode Design for Battery-Operated Systems
4. Setup D
Setup D devices have a good connection to earth ground because of their size and
construction. They can be treated like grounded devices.
Setup D devices consist of multiple modules, large metallic parts like chassis or metallic
housing and usually have dimensions of 20cm and more. Typical examples are
Laptops, large table top devices or appliances.
The electrode design follows the rules described in Chapter 3. “GestIC® Standard
Electrode Design” (Standard Electrodes) and Chapter 5. “Boosted Electrode
Design” (Boosted Electrodes).
4.1.2
Parameterization
The parameterization of battery optimized designs should be done in the non-grounded
condition. The resulting parameter set is valid for the grounded case, too.
Performance validation and parameterization require a wireless connection to the PC
running Aurea, e.g., IR or Bluetooth. For further details, contact Microchip.
 2013-2016 Microchip Technology Inc.
DS40001716C-page 27
GestIC® Design Guide
NOTES:
DS40001716C-page 28
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Chapter 5. Boosted Electrode Design
5.1
CIRCUITRY FOR TX BOOST
GestIC® standard electrode design is applicable up to a maximum electrode size and
within the detection range. An enhanced electrode design allows to boost the Tx voltage to overcome these limits.
This approach requires a Tx level shifter like MCP1416, which allows increasing the Tx
amplitude to values of up to 18V. It is recommended to provide its DC input voltage from
an available voltage in the customer’s system. If not available, it can be generated by
a step-up controller like MCP1661.
If a step-up other than MCP1661 is used, it is recommended that the switching frequencies and noise are above MGC3XXX operating frequencies (44-250 kHz). The whole
circuitry is shown in Figure 5-1.
FIGURE 5-1:
TX BOOST CIRCUITRY
MGC3XXX can be used as well in combination with the high-performance MTCH6303
2D Touch Controller and the MTCH652 Line Driver with boost functionality to create a
unique 2D/3D sensing solution. The line driver MTCH652 can drive up to 19 Tx channels with up to 18V. The MTCH652 Line Driver will be shared for 2D and 3D operation.
The control will be automatically handled in the firmware of MTCH6303 and MGC31XX.
A block diagram is shown in Figure 5-2. For further details, contact Microchip.
FIGURE 5-2:
2D/3D MULTIPLEXING WITH COMMON Tx DRIVER
2D Rx
2D Rx
2D Rx
2D Rx
Touchpanel
GIC-EL
GIC-EL
MTCH652
2D Tx
MTCH6303
 2013-2016 Microchip Technology Inc.
3D Tx
MGC3130
DS40001716C-page 29
GestIC® Design Guide
5.2
ELECTRODE DESIGN FOR 3D ONLY SYSTEMS
In order to keep a stable working point and protect the MGC3XXX inputs from signal
overload, it is mandatory to separate the physical Tx electrode area from the Rx input
electrodes. Boosted Tx electrodes are not placed underneath the Rx electrodes as typical for standard GestIC systems (refer to Chapter 3. “GestIC® Standard Electrode
Design”). Instead, they are laid out in the same layer as the Rx electrodes.
It is recommended to place a GND layer underneath the GestIC electrode arrangement. Figure 5-3 shows a typical sensor design for boosted systems.
FIGURE 5-3:
BOOSTED ELECTRODE DESIGN
Layer stack: 1Ͳ2mm between
Layer1 (top)
Layer2 (bottom)
top and bottom
North
Tx (boosted)
East
West
Rx + Tx
GND
Conductive layer
Isolation
Conductive layer
South
GND
The design rules for boosted systems are different from those for standard electrodes
and they are summarized below:
5.2.1
Rx electrodes
Rx electrodes are designed as a frame like standard electrodes as described in
Section 3.1.2 “Rx Electrodes”.
The width of the electrodes depends on the sensor size:
• < 140 mm: 4-7% of the electrode’s length
• > 140 mm: 5-7 mm is recommended, smaller values (e.g., 2 mm) are in characterization
The center area is used for boosted Tx and thus, no center electrode is supported.
5.2.2
Tx electrodes
The boosted Tx electrode is placed in the center of the Rx frame. In order to limit the
noise coupling between boosted Tx and Rx, it is mandatory to keep a 3-5 mm distance
between the Rx and Tx electrodes.
Holes and cutouts in the Tx electrodes are allowed, but it is recommended that the Tx
electrode covers 70-80% of the electrode area.
FIGURE 5-4:
Tx ELECTRODE FOR BOOSTED SENSOR
Layer1 (top)
3Ͳ5mm
Tx (boosted)
DS40001716C-page 30
 2013-2016 Microchip Technology Inc.
Boosted Electrode Design
5.2.3
Rx Feeding Lines
Unlike proposed for standard sensor designs, Rx feeding lines should be kept apart
from the boosted Tx structures. It is recommended to route them next to the Rx electrodes or inside the GND layer. It is recommended to leave a 0.3-0.5 mm space
between feeding lines and GND.
FIGURE 5-5:
Rx FEEDING LINES FOR BOOSTED SENSOR
0͘3Ͳ0͘5mm
3Ͳ5mm
>1mm
Feeding lines in
top layer,
GND in bottom layer
5.2.4
GND
Feeding lŝŶĞƐ in
bottom lĂyeƌ ;GND)
Chip Placement
The MGC3XXX device should be placed outside of the sensor frame and kept away
from boosted Tx structures.
5.2.5
Layer Stack
A 2-layer stack consisting of GestIC electrodes in the top layer and GND in the bottom
layer is recommended. The distance between the layers is 1-2 mm for PCB material
(εr = 5) and it goes down to 0.5 mm for plastic material (εr < 3).
Single layer designs are, in general, possible but object of further investigation.
Boosted electrode designs have been verified up to a 300 mm x 300 mm dimension
and a maximum Tx amplitude of 18V.
5.2.6
Optimization of Rx-Tx Coupling
The boosted GestIC system uses mutual effects between Rx and Tx to measure the
presence of the human hand. Sensor signals increase with the hand’s approach. In
very close proximity (< 1 mm), or if the hand touches the electrodes, however, the signals may decrease with the hand’s approach due to transmission effects.
For that reason, it is recommended to design boosted GestIC sensors with a 1-2 mm
thick cover on top of the sensor.
Furthermore, it is recommended to add capacitances between Rx and (non-boosted)
Tx pins of the MGC3XXX. 10 pF give an optimum between performance reduction and
transmission effects.
The capacitors are included in the boosted reference circuitry in Appendix
D. “Reference Circuitry for MGC3130 Boosted”.
 2013-2016 Microchip Technology Inc.
DS40001716C-page 31
GestIC® Design Guide
NOTES:
DS40001716C-page 32
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Chapter 6. Sensor Integration and Common Mistakes
6.1
GestIC® AND GROUND
Special attention must be given to the ground (GND) around the GestIC® sensor. GND
has a shielding function, but at the same time it takes sensitivity from the GestIC
sensor.
Different rules apply for GestIC standard designs and boosted designs.
The following rules apply for standard designs:
1. Keep GND away from Rx electrodes
A distance of 3-5 mm should be kept as a minimum. Especially inside the sensor area,
it is recommended to avoid GND areas.
2. Keep GND away from Rx feeding lines
The same rules apply as for the Rx electrodes. In particular, the Rx feeding lines should
not be routed inside a GND plane.
3. Shield with Tx
A good GND connection is necessary for the signal integrity of the digital circuitry of
MGC3XXX and connected parts. If these parts are assembled on the same board as
the GestIC sensor, it is recommended to shield the GND area with a Tx layer (refer to
Section 3.1.5 “Layer Stack”).
GestIC® AND GND
FIGURE 6-1:
>5mm
GND
Avoid GND in the center,
Ŭeep distance
Rx
Min. 3Ͳ5mm
More distance
is better
GND
Shield with Tx
Tx
GND
The following rules apply for boosted designs:
1. Shield Rx electrodes with GND
A GND layer behind the Rx electrodes adds stability to the whole system and limits
noise coupling from the boosted Tx layer. A minimum distance of approximately 1 mm
should be kept between Rx and GND.
2. Shield Rx feeding lines with GND
Rx feeding lines must be shielded from boosted Tx and that can be done with GND. It
is recommended to route feeding lines inside the GND layer. A distance of 0.3-0.5 mm
should be kept between Rx feeding lines and GND.
 2013-2016 Microchip Technology Inc.
DS40001716C-page 33
GestIC® Design Guide
6.2
SENSOR LAYOUT ON A PCB
A lot of applications have the GestIC sensor built on a 2 or a 4-layer PCB (Printed
Circuit Board), and in many cases it is combined with the gesture controller and even
with other circuitry. These combinations require a strict separation between the circuitry
and the GestIC electrode structures. If the additional components are placed in the
center of the sensor board, a 4-layer PCB is recommended to allow an electrode
shielding with a Tx layer.
Some additional tips on how to integrate the GestIC sensor on a PCB layout are
provided below:
1. Separate digital and analog domains on the MGC3XXX gesture controller.
- low-impedance GND connection is required for digital signals
- keep area around Rx pads and feeding lines clear from GND, as indicated in
Figure 6-2 (if necessary, apply Tx for shielding)
SEPARATION OF Rx PADS, FEEDING LINES AND GND
Digital
circuitry
GND
Tx
Feeding lines
FIGURE 6-2:
MGC
2. Do not place vias inside the Rx electrodes and do not place routes in the Rx
layer, as shown in Figure 6-3.
FIGURE 6-3:
Rx LAYER
Rx
NO
NO
3. Avoid to place routes in the Tx layer, as indicated in Figure 6-4.
FIGURE 6-4:
Tx LAYER
Tx
Avoid
DS40001716C-page 34
 2013-2016 Microchip Technology Inc.
Sensor Integration and Common Mistakes
4. Empty layers should not be filled with copper (Figure 6-5). Some PCB
manufacturers misinterpret empty layers as “full copper”. Add text or small
structures into the empty layers.
FIGURE 6-5:
EMPTY LAYERS
L4
L3
L2 - empty
L1
5. Check with PCB manufacturer if required hatching structures can be
manufactured, as shown in Figure 6-6. Some PCB manufacturers may interpret
hatched areas as “full copper”.
FIGURE 6-6:
6.3
HATCHING STRUCTURES
COMMON MISTAKES OF GestIC ELECTRODE DESIGN
Table 6-1 lists the most common mistakes of a GestIC sensor design and offers
suggestions for possible countermeasures.
TABLE 6-1:
COMMON MISTAKES IN GestIC® SENSOR DESIGN
Observation
Recognition range
is low
Mistake
Electrode size is too small
Countermeasure
Extend available space for GestIC®
sensor (Section 3.1.1 “Sensor
Outline”)
Recognition range Electrode layer stack is not optimal
is low
Increase distance between Rx and Tx
(Section 3.1.5 “Layer Stack”)
Rx electrodes are too close to GND
Recognition range
areas
is low
Increase distance between Rx and
GND (Section 3.1.5 “Layer
Stack”)
Recognition range Sensor outline is asymmetric
in one direction is
lower than in the
other
Increase symmetry – use a square or
circular design
(Section 3.1.5 “Layer Stack”)
Rx signals are
noisy
Rx electrodes or Rx feeding lines
are routed too close to digital signals
Increase the distance to digital lines
and shield feeding lines with Tx (ch.
Section 3.1.2 “Rx Electrodes”
to Section 3.1.4 “Chip Place-
ment and Rx Feeding Lines”)
Rx signals are
jumping or drifting
Rx signals are
noisy
 2013-2016 Microchip Technology Inc.
Feeding lines are mechanically
instable
Care for mechanically stable conditions
(ch. Section 3.1.4 “Chip Placement and Rx Feeding Lines”)
Capacitance between Tx and GND
is too high
Improve layer stack, change to a
cross-hatched Tx layer
(Section 3.1.5 “Layer Stack”)
DS40001716C-page 35
GestIC® Design Guide
NOTES:
DS40001716C-page 36
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Appendix A. GestIC® Design-In Checklist
GestIC® DESIGN-IN CHECKLIST
FIGURE A-1:
Project:
Check
Date:
Item
Details
Application
†
Use Case
†
Sensor range expectation
†
Sensor features
†
Available
space
for
the
sensor
Mechanical construction of the device
†
Drawing
†
Dimensions
†
Placement of building blocks
†
Metallic/conductive parts
Electrical circuitry
†
Block diagram
†
Power supply
†
Host controller
†
Peripherals
†
Interconnection
Ground and Noise
†
Connection to Earth Ground
†
Possible noise sources within
the system
 2013-2016 Microchip Technology Inc.
DS40001716C-page 37
GestIC® Design Guide
NOTES:
DS40001716C-page 38
 2013-2016 Microchip Technology Inc.
 2013-2016 Microchip Technology Inc.
J1
GND
VDD_3V3
GND
1
2 VDD_3V3
3
4
5
6
EIO1
EIO2
EIO3
EIO6
EIO7
GND
J3
1
2
3
4
5
6
GND
Gesture Port
TS
VDD
GND
SDA
SCL
MCLR
J2
Pin assignment for
Hillstar/Woodstar
I2C-to-USB bridge
I2C
VDD 3.3V (+-5%)
GND
2 1
R2
1K8
R1
10k
10k
R4
EIO1/IS1
EIO2
EIO3
EIO6
EIO7
1K8
R3
VDD_3V3
SDA0
SCL0
MCLR
EIO0/TS
VDD_3V3
GND
2
1
9
11
27
3
10
29
28
24
EIO1/IS1
16
17
C3
18
4.7uF 26
GND
4.7uF
C2
GND
0.1uF
C1
MCLR
IS2
EIO0
EIO1
EIO2
EIO3
SI0
SI1
SI2
SI3
RX0
RX1
RX2
RX3
RX4
TXD
15
12
13
14
19
20
21
22
23
4
5
6
7
8
25
IS2
GND
10k
GND
R8
10k
DNP
R6
R7
DNP
VDD_3V3
R5
VDD_3V3
Interface Selection
NC
NC
NC
NC
VINDS
VCAPS
VCAPA
VCAPD
VSS1
VSS2
VSS3
EPAD
VDD
MCLR
U1
0*&
GestIC¤ Chip
IS2
EIO0/TS
EIO1/IS1
EIO2
EIO3
SDA0
SCL0
EIO6
EIO7
RX0
RX1
RX2
RX3
RX4
TX
1
0
IS2
0
0
IS1
Mode (Address)
)#Slave Address 1 (0x43)
I2C Slave Address 1 (0x42)
RX4
RX3
TX
RX2
RX1
RX0
FB1
R13
R12
R11
R10
R9
10k
10k
10k
10k
10k
GND
J4
RX0
RX1
RX2
TX
RX3
RX4
GND
Pin assignment for
Hillstar/Woodstar
Standard Electrodes
Electrode Connector
FIGURE B-1:
1 2 3 4 5 6 7
Power
GestIC® DESIGN GUIDE
Appendix B. Reference Circuitry for MGC3130
REFERENCE CIRCUITRY FOR MGC3130
DS40001716C-page 39
GestIC® Design Guide
NOTES:
DS40001716C-page 40
 2013-2016 Microchip Technology Inc.
J1
Power
GND
VDD_3V3
GND
1
2 VDD_3V3
3
4
5
6
EIO1
EIO2
EIO3
EIO6
EIO7
GND
J3
1
2
3
4
5
6
GND
Gesture Port
TS
VDD
GND
SDA
SCL
MCLR
J2
Pin assignment for
Hillstar/Woodstar
I2C-to-USB bridge
I2C
2 1
 2013-2016 Microchip Technology Inc.
R2
1K8
R1
10k
10k
R4
EIO1/IS1
EIO2
EIO3
EIO6
EIO7
1K8
R3
VDD_3V3
SDA0
SCL0
MCLR
EIO0/TS
VDD_3V3
GND
EIO1/IS1
4.7uF
GND
C3
4.7uF
5
6
7
14
26
18
28
19
16
20
27
17
13
C2
GND
0.1uF
C1
MCLR
EIO0
EIO1
EIO2
EIO3
EIO4/SI0
EIO5/SI1
EIO6/SI2
EIO7/SI3
IS2
TXD
RX0
RX1
RX2
RX3
RX4
IS2
GND
10k
GND
R8
10k
DNP
R6
R7
DNP
VDD_3V3
1
2
3
8
9
10
11
12
4
15
21
22
23
24
25
R5
VDD_3V3
Interface Selection
NC
NC
NC
NC
VCAPA
VCAPS
VCAPD
VINDS
VSS1
VSS2
VSS3
VDD
MCLR
U1
MGC3030
GestIC¤ Chip
1
0
IS2
EIO0/TS
EIO1/IS1
EIO2
EIO3
SDA0
SCL0
EIO6
EIO7
IS2
TX
RX0
RX1
RX2
RX3
RX4
0
0
IS1
Mode (Address)
I2C 0 Slave Address 1 (0x43)
I2C Slave Address 1 (0x42)
RX4
RX3
TX
RX2
RX1
RX0
FB1
R13
R12
R11
R10
R9
10k
10k
10k
10k
10k
GND
J4
RX0
RX1
RX2
TX
RX3
RX4
GND
Pin assignment for
Hillstar/Woodstar
Standard Electrodes
Electrode Connector
1 2 3 4 5 6 7
FIGURE C-1:
VDD 3.3V (+-5%)
GND
GestIC® DESIGN GUIDE
Appendix C. Reference Circuitry for MGC3030
REFERENCE CIRCUITRY FOR MGC3030
DS40001716C-page 41
GestIC® Design Guide
NOTES:
DS40001716C-page 42
 2013-2016 Microchip Technology Inc.
J1
GND
VDD_3V3
GND
1
2 VDD_3V3
3
4
5
6
EIO1
EIO2
EIO3
EIO6
EIO7
GND
J3
1
2
3
4
5
6
GND
Gesture Port
TS
VDD
GND
SDA
SCL
MCLR
J2
Pin assignment for
Hillstar/Woodstar
I2C-to-USB bridge
I2C
VDD 3.3V (+-5%)
GND
Power
R2
1K8
R1
10k
10k
R4
EIO1/IS1
EIO2
EIO3
EIO6
EIO7
1K8
R3
VDD_3V3
X)
9
C4
SDA0
SCL0
MCLR
EIO0/TS
GND
VDD_3V3
4
5
GND
VDD_3V3
EN
VIN
4.7μH
L1
1
SW
GND
2
 2013-2016 Microchip Technology Inc.
2 1
D1
3
GND
2
1
9
11
27
3
10
29
28
24
EIO1/IS1
120K
120K
120K
120K
1.6M
1.05M
860K
370K
IS2
EIO0
EIO1
EIO2
EIO3
SI0
SI1
SI2
SI3
RX0
RX1
RX2
RX3
RX4
15
12
13
14
19
20
21
22
23
4
5
6
7
8
IS2
GND
10k
GND
R8
10k
DNP
R6
R7
DNP
VDD_3V3
R5
VDD_3V3
5V
10V
12V
18V
25
Interface Selection
NC
NC
NC
NC
VINDS
VCAPS
VCAPA
VCAPD
VSS1
VSS2
VSS3
EPAD
VDD
MCLR
TXD
GestIC¤ Chip
R15
R14
IS2
EIO0/TS
EIO1/IS1
EIO2
EIO3
SDA0
SCL0
EIO6
EIO7
RX0
RX1
RX2
RX3
RX4
FB1
VDD_Boost
0.1uF
50V
0603
GND
C6
10uF
35V
1206
VDD_Boost
C5
GND
U1
0*&
120k
1%
R15
1.6M
1%
R14
VDD_Boost = ca. 18V
16
17
C3
18
4.7uF
26
GND
4.7uF
C2
GND
0.1uF
C1
MCLR
MCP1661T-E/OT
U2
FB
PMEG2005EH,115
1
0
IS2
0
0
IS1
TX
TX
GND
I2C 0 Slave Address 1 (0x43)
I2C Slave Address 1 (0x42)
Mode (Address)
TX
VDD_Boost
4
3
2
5
RX0
RX1
RX2
RX3
RX4
N
N
N
N
R13
N
DNP
C11
R12
DNP
C10
R11
DNP
C9
R10
DNP
C8
R9
DNP
C7
MCP1416T-E/OT
U3
TX Level Shifter
TX_Boost
TX_Boost
GND
J4
TX_Boost
GND
RX4
RX3
RX2
RX1
RX0
Pin assignment for
Hillstar/Woodstar
Boosted Electrodes
Electrode Connector
FIGURE D-1:
7 6 5 4 3 2 1
Step Up Converter
GestIC® DESIGN GUIDE
Appendix D. Reference Circuitry for MGC3130 Boosted
REFERENCE CIRCUITRY FOR MGC3130 BOOSTED
DS40001716C-page 43
GestIC® Design Guide
NOTES:
DS40001716C-page 44
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Appendix E. GestIC® Equivalent Circuitry and Capacitance Design Goals
GestIC® EQUIVALENT CIRCUITRY AND CAPACITANCE
DESIGN GOALS
FIGURE E-1:
GND
CTxGND
Tx load <1nF
CTxH
Human Hand
Tx
Tx
CRxTx
„Base Coupling“
CRxH
CL
ADC
Rx
CHGND
CRxGND
CBh&
MGC3XXX
CHBM
CGNDEarth
Earth
„Grounding“
GND
Where,
Tx, Rx
CRxTx
Tx and Rx electrodes of the GestIC® sensor
Capacitance between Rx and Tx electrode (base coupling)
CRxGND
Capacitance between Rx electrode and system ground
CTxGND
Capacitance between Tx electrode and system ground (capacitive load of the
GestIC system)
CHGND, CRxH, CTxH Capacitances between human hand and GestIC sensor
CHBM
Capacitance between human body and earth ground (“Human Body Model”)
CGNDEarth
Capacitance between earth ground and GestIC system ground (actual
CBUF
CL
“grounding”)
Input Capacitance of the MGC3XXX Rx pin (approximately 5 pF)
Capacitance of the Rx feeding lines
 2013-2016 Microchip Technology Inc.
DS40001716C-page 45
GestIC® Design Guide
TABLE E-1:
Capacitance
Standard Electrode
Standard Electrode
Battery operation
Boosted Electrode
CRXTX
5-20 pF
5-20 pF
< 5 pF
CRXGND
5-20 pF
5-20 pF
5-20 pF
CTXGND
< 1 nF
< 1 nF
it depends from booster
driving capabilities
CTXH
0.1 pF
0.1pF
0.1pF
CRXH
0.1 pF
0.1pF
0.1pF
CHGND
0.1 pF
0.1pF
0.1pF
CHBM
>> CHGND, CRxH, CTxH
>> CHGND, CRxH, CTxH
>> CHGND, CRxH, CTxH
CGNDEARTH
Note 1:
2:
DS40001716C-page 46
CAPACITANCE DESIGN GOALS
>> CHGND, CRxH, CTxH n.a.
>> CHGND, CRxH, CTxH
Rule for Standard Electrode best operation: CRXGND + CBUF = CRXTX + CL
Rule for Boosted Electrode best operation: CRXGND + CBUF > = CRXTX + CL
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Appendix F. GestIC® Performance Evaluation
F.1
ANALOG FRONT END (AFE)
AFE parameters are tuned according to the electrode capacitances and indicate a good
or bad electrode design.
Signal Matching values represent the status of the capacitive voltage divider (CRXGND)
+ CBUF | CRXTX + CL). They are good between 10-180 counts. Higher values are an
indication for a high capacitance between Rx and GND (CRXGND), and will cause a
lower sensor performance.
The Rx signal represents a half cycle of the ADC input signal. In an optimal electrode
design, the following conditions will apply:
- Rx signal goes through the sampling point (+/-20%)
- Rx signal is settled at sampling time
- Rx signal has a maximum clipping of 2 ms
If these conditions are not met, the Tx signal cannot be driven (CTXGND too high) and
an increased noise level must be expected.
FIGURE F-1:
 2013-2016 Microchip Technology Inc.
AFE
PARAMETERIZATION
ELECTRODE)
(HILLSTAR
STANDARD
DS40001716C-page 47
GestIC® Design Guide
F.2
SIGNAL DEVIATION
Signal deviation (SD) is the signal change when the hand approaches. It is measured
with an artificial hand 3 cm above the center of an electrode. The following minimum
values are required:
- SD at near end (directly above the electrode): > 200 counts
- SD at far end (measured at the opposite electrode): > 12 counts
Aurea supports SD measurement in the Extended Parameterization.
FIGURE F-2:
TABLE F-1:
SD MEASUREMENT WITH AUREA HELP
SIGNAL DEVIATION TYPICAL VALUES
Standard Electrode –
(Hillstar 95x60 mm)
S
W
N
E
C
Near End
374
342
367
350
437
Far End
120
42
115
50
n/a
S
W
N
E
C
Near End
290
301
301
208
0
Far End
119
124
96
103
n/a
S
W
N
E
C
Near End
1409
1620
1613
1229
0
Far End
186
85
245
54
n/a
Standard Electrode –
Battery Operation
Boosted Electrode
DS40001716C-page 48
 2013-2016 Microchip Technology Inc.
GestIC® Performance Evaluation
F.3
NOISE VALUES
Several methods are used to characterize the noise of a GestIC system.
1. Aurea Noise Level:
100s average of CIC signal standard deviation, measures internal and external noise
floor (select in Aurea Signals tab)
2. Noise variance:
Value for the external noise floor, measured between 200-1000 Hz (shown with CIC
values in Aurea Signals tab, available via I2C messages)
3. CIC STD:
Standard deviation of CIC values over 1024 samples
4. CIC PP:
Peak-to-Peak values of CIC values over 1024 samples
Typical values are listed in the table below.
TABLE F-2:
GestIC® NOISE TYPICAL VALUES (Tx = 103 kHz)
Standard Electrode –
(Hillstar 95x60)
S
W
N
E
C
Aurea Noise Level
2,0
2,3
2,3
2,0
2,9
CIC STD
2,2
2,0
2,8
1,7
2,5
CIC PP
12,7
10,6
15,0
13,0
12,8
Noise Variance
Standard Electrode –
Battery Operation
Aurea Noise Level
0,0016
S
W
N
E
C
3,7
2,9
2,7
2,3
0,0
CIC STD
3,2
3,9
2,6
2,7
0,0
CIC PP
17,6
18,6
18,6
16,9
0,3
Noise Variance
Boosted Electrode
Aurea Noise Level
0,0039
S
W
N
E
C
2,5
2,3
3,0
2,1
0,0
CIC STD
3,3
3,5
3,8
2,5
0,0
CIC PP
17,8
19,6
21,2
15,8
0,1
Noise Variance
Note 1:
2:
3:
0,0040
Noise values should be close to the typical values, higher noise will degrade
GestIC® performance.
All 4-frame electrodes (NESW) should have noise values in the same range, if one
or more electrodes have higher noise, check signal integrity (crosstalk) of your
system.
Different noise values will be measured at different GestIC Tx frequencies, it is
recommended to check all.
 2013-2016 Microchip Technology Inc.
DS40001716C-page 49
GestIC® Design Guide
F.4
RECOGNITION RANGE
The Sensor Recognition Range is defined as the maximum distance of the human
hand from the sensor surface to track the position and to recognize gestures.
Depending on the feature, different recognition ranges can be defined.
TABLE F-3:
Standard
Electrode –
(Hillstar 95x60)
Battery Operation –
Setup A (70 x 70 mm)
Boosted Electrode
8” (210 x 135 mm)
Flick Recognition N-S
60 mm
40 mm
140 mm
Flick Recognition E-W
50 mm
40 mm
130 mm
Proximity Range
140 mm
100 mm
320 mm
FIGURE F-3:
DS40001716C-page 50
GESTURE RECOGNITION RANGE TYPICAL VALUES
MEASUREMENT OF GESTURE RECOGNITION RANGE
 2013-2016 Microchip Technology Inc.
GestIC® DESIGN GUIDE
Appendix G. GestIC® Hardware References
G.1
GESTIC® HARDWARE REFERENCES
The GestIC® Hardware References package contains the PCB layouts (Gerber files)
for the MGC3XXX development kits (Hillstar, Woodstar) and a collection of electrode
reference designs fitting both kits. In addition, the package includes designs, parameter
files and host code of various demonstrators which represent complete systems for
embedded or PC-based applications.
New designs will be added to the package once they are available. The GestIC
Hardware Reference package can be downloaded from the Microchip website at
http://www.microchip.com/gesticresources.
 2013-2016 Microchip Technology Inc.
DS40001716C-page 51
GestIC® Design Guide
NOTES:
DS40001716C-page 52
 2013-2016 Microchip Technology Inc.
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 2013-2016 Microchip Technology Inc.
DS40001716C-page 53