IQS128EV04 S Azoteq, IQS128EV04 S Datasheet - Page 19

• 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

Byte Definitions for Streaming Mode
Azoteq provides a
Interface) application that can be utilised to
capture and visualise the data streamed from
the IQS128/IQS128L.
8 Automatic Tuning
ATI
implemented
ProxSense
performance of the sensor in a wide range of
applications and environmental conditions
(refer
Automatic Tuning Implementation).
ATI makes adjustments through external
reference
required by most other solutions) to obtain
optimum performance.
Copyright © Azoteq (Pty) Ltd 2012
All Rights Reserved
Byte
0
1
2
3
4
5
6
7
Implementation (ATI)
is
to
7:0
15:8
23:16
31:24
39
38
37
36
35
34
33
32
47
46
45
44
43
42
41
40
55:54
53
52
51
50
49
48
63:56
Bit
®
application
a
capacitors
devices that optimises the
in
CS High byte
CS Low byte
LTA High byte
LTA Low byte
ATI busy
Proximity Event Detected
Touch Event Dectected
OUT State Indication
Not Used
Zoom active
Not Used
Not Used
ATI Multiplier (I)
ATI Multiplier (S)
ATI Multiplier (S)
Compensation (P4)
Compensation (P3)
Compensation (P2)
Compensation (P1)
Compensation (P0)
Not Used
Compensation (P5)
Touch Threshold Bit 2
Touch Threshold Bit 1
Touch Threshold Bit 0
Proximity Threshold Bit 1
Proximity Threshold Bit 0
Counter
sophisticated
the
GUI
IQ Switch
note
unnecessary
Value
latest
(Graphical User
AZD0027
®
technology
generation
ProxSense
IQS128 & IQS128L Datasheet v2.4
(as
-
®
Series
8.1 ATI
The IQS128/IQS128L implements an ATI
algorithm.
parameters
electrode’s connection to the device.
The device will execute the ATI algorithm
whenever the device starts-up and or when
the CS are not within a predetermined range.
There
understand for ATI:
8.1.1 ATI Target
ATI adjusts internal circuitry according to two
parameters, the ATI multiplier and the ATI
compensation.
•
•
With these two parameters the CS of the
IQS128/IQS128L is tuned until an ATI target
value of 1600 is achieved.
8.1.2 ATI
As mentioned above, the ATI multiplier is
used to select a base value for the ATI. The
ATI BASE value is important, as this
determines the sensitivity of the device. The
sensitivity can be defined as:
Sensitivity = ATI TARGET / ATI BASE
The ATI Target remains fixed at 1600 and it
can thus be seen from this that a larger base
value will result in a less sensitive device.
The
increase/reduce the sensitivity of the system
through the ATI BASE value. For most
applications the ATI BASE should be kept
default.
The ATI multiplier can be viewed as a
course adjustment of CS, used to
achieve the ATI BASE value.
The
adjustment used to reach the ATI
TARGET value.
designer
are
ATI
BASE
This algorithm adjusts the ATI
2
to
: Significance of ATI Base
compensation
important
optimise
has
the
definitions
the
option
is
Page 19 of 33
sensing
April 2013
a
fine
to
to