IQS128EV04 S Azoteq, IQS128EV04 S Datasheet - Page 20

• Manufacturer Part Number: IQS128EV04 S
• Description: Touch Sensor Development Tools Long range IQS128 proximity kit
• Manufacturer: Azoteq

Specifications of IQS128EV04 S

• Tool Is For Evaluation Of: IQS128
• Interface Type: LED
• Operating Voltage: 2.95 V to 5.5 V

The options for the ATI BASE is as follows:
IQS128
Configuration: Bank2 bit 2-1
ATI
Bit
00
01
10
11
IQS128L
Configuration: Bank2 bit 3-1
ATI
Bit
000
001
010
011
100
101
110
111
8.2 Sensitivity due to ATI
The adjustment of the ATI parameters will
result in variations in the CS and sensitivity.
Sensitivity can be observed as the change in
CS as the result of a fixed change in sensed
capacitance. The ATI parameters have been
chosen to provide significant overlap. It may
therefore be possible to select various
combinations of ATI multiplier and ATI
compensation settings to obtain the same
CS. The sensitivity of the various options
may however be different for the same CS.
8.3 ATI Procedure
While the ATI algorithm is in progress this
condition will be indicated in the streaming
data and proximity and touch events cannot
be detected.
remain in this condition and it will be entered
only when relatively large shifts in the CS
has been detected.
The ATI function aims to maintain a constant
CS, regardless of the capacitance of the
sense electrode (within the maximum range
of the device).
The effects of ATI on the application are the
following:
Copyright © Azoteq (Pty) Ltd 2012
All Rights Reserved
BASE1
BASE2
Selection
200
100
150
250 (Least sensitive)
Selection
200
250
300
350
400
550
700
850
:ATI
:ATI
BASE0
BASE0
(Most sensitive)
(Most sensitive)
(Least sensitive)
The device will only briefly
ATI BASE values
ATI BASE values
IQ Switch
®
ProxSense
IQS128 & IQS128L Datasheet v2.4
®
Series
ATI can be implemented so effectively due
to:
Automatic adjustment of the device
configuration
parameters for a wide range of PCB
and application designs to maintain a
optimal configuration for proximity and
touch detection.
Automatic
electrode at start-up to optimise the
sensitivity of the application.
Automatic re-tuning when the device
detects
electrode’s
accommodate
changes in the environment of the
application
sensing electrode.
Re-tuning only occurs during device
operation when a relatively large
sensitivity reduction is detected. This
is to ensure smooth operation of the
device during operation.
Re-tuning may temporarily influences
the normal functioning of the device,
but in most instances the effect will be
hardly noticeable.
Shortly after the completion of the re-
tuning process the sensitivity of a
Proximity detection may be reduced
slightly for a few seconds as internal
filters stabilises.
Excellent system signal to noise ratio
(SNR).
Effective digital signal processing to
remove AC and other noise.
The very stable core of the devices.
The
accommodate
sensing electrode capacitances.
built-in
changes
tuning
that
a
a
capacitance
and
large
large
in
influences
capability
of
the
the
processing
Page 20 of 33
range
range
sensing
April 2013
sense
the
to
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to
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