IQS550EV03 S Azoteq, IQS550EV03 S Datasheet - Page 28

• Manufacturer Part Number: IQS550EV03 S
• Description: Touch Sensor Development Tools Trackpad Demo for IQS550
• Manufacturer: Azoteq

Specifications of IQS550EV03 S

• Tool Is For Evaluation Of: IQS550
• Interface Type: I2C, SPI
• Operating Voltage: 1.65 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C

5.6.14 Timing Settings (0x14)
On-chip timings can be adjusted here, and are
explained below.
Reseed Time
The reseed time is the time that a channel
allows a prox/touch to continually be set,
before assuming it is a fault condition. Once
this time has elapsed, a reseed is forced to
correct the condition. In Normal Mode, all the
channels
channel) are reseeded. For the default value,
if a prox/touch is seen anywhere on the touch
panel for 40s, a global reseed will be executed
to remove this assumed stuck condition. It is
recommended to make this timeout quite long,
since it is unpleasant to have the device
reseed while drawing on the panel.
master can however still send the Reseed
command anytime
relative to the application are assumed.
When this occurs in ProxMode, only the
ProxMode channel is reseeded.
The configurable value works in multiples of
500ms, thus the default value of 80, will select
a ReseedTime of 40s.
Comms Timeout
This is a timer that monitors the activity on the
I
this within this time a timeout will occur, and
the
resuming sensing.
This
conditions caused by errors on the I
can also be used as a RDY timeout, thus if the
master
communication, and does not mind missing a
Copyright © Azoteq (Pty) Ltd
All Rights Reserved.
2
C bus. If there is no successful read/write
communication
assists
cannot
(not
0 = Touch filtering enabled
1 = Touch filtering disabled
in
including
overcoming
always
when fault
window
the
service
will
any
ProxSense
ProxMode
conditions
2
C bus. It
IQ Switch
close,
stuck
The
the
IQS550 Trackpad Datasheet
®
cycle‟s data, then the RDY will only be high for
the Comms Timeout time, and then it will go
low, and the cycle will continue.
Mode Time
This timer is responsible for the timings used
when implementing the Automatic
control, and also the low-power timings. The
value used here is also a multiple of 500ms.
For more details see Section 3.4 and Section
3.5
Low-Power Time
Here the low-power timing can be adjusted.
Predetermined intervals can be selected here
to configure how long the device will sleep
between data acquisitions in the Low-Power
charging mode. Clearly the longer the sleep
time, the lower the power consumption will be,
at
Typically the ProxMode channel will be setup
to provide a good distance proximity. This will
give the device enough time to be up and
running before the user interacts with the
trackpad channels, even if the LPTime is
selected to be reasonably long.
Sleep Time
This is a sleep interval that is permanently
added to each cycle in Normal Mode, unlike
the Low-Power which is only added under
certain
prox/touch is sensed). This can be used in
current sensitive designs, where a rapid
response
For example, if a normal cycle took ~10ms in
total, then adding a 10ms SleepTime could
almost halve the total current consumption.
This would add to any Low-Power timing.
Revision 1.04
Series
®
the
conditions (for example
expense
rate
of
is
response
not
November 2012
Page 28 of 50
crucial.
if
Mode
time.
no