IQS550EV03 S Azoteq, IQS550EV03 S Datasheet - Page 9

• 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

the trackpad sensors are enabled. This gives
a good proximity sensor in the trackpad area.
3.4 Automatic Mode Switching
With this enabled, automatic interaction and
switching between Normal- and ProxMode
charging is achieved. For the automatic mode
(and also low-power charging) a selectable
ModeTime is used.
After being correctly configured, the system
will operate in ProxMode, until a proximity
event is sensed on the ProxMode channel. At
this point the system will switch to Normal
Mode
interaction with the trackpad channels.
The system will revert back to ProxMode
charging if no prox, touch or snap condition is
found on the Normal Mode channels for a
period of ModeTime.
When
conversion
roughly every 4s, but no communication for
this cycle will be presented.
simply to keep the Long-Term Average values
of the Normal Mode channels up to date.
3.5 Low Power Charging
By enabling low-power, the device will add a
sleep between conversions. If no prox, touch
or snap is sensed for ModeTime, then the
system will go into the low duty-cycle charging
mode.
sensed, the system will resume full-speed
charging.
cycle into the system naturally decreases total
power consumption of the device, dependant
on the selected LPTime.
3.5.1 Low-Power with Automatic Mode
If it is possible to have a ProxMode sensor,
the best is to use the system in automatic
mode switching, combined with low-power
charging.
power consumption, and works as follows:
The system charges in ProxMode until a
PROX event occurs, and since automatic
mode is enabled, it will switch to Normal Mode
charging which occurs at full-speed (no low-
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All Rights Reserved.
Switching
charging,
in
As soon as a channel output is
This will give by far the lowest
Introducing this low-power duty
ProxMode,
will
automatically
ready
a
to
Normal
This cycle is
sense
take
ProxSense
IQ Switch
Mode
place
user
IQS550 Trackpad Datasheet
®
power). If no activity occurs for ModeTime,
then the system will revert to ProxMode
charging. Here it will continue at full-speed for
a further ModeTime, and after this, low-power
charging will take place on the ProxMode
channel.
This gives the lowest power consumption,
combined with a possibility of good range
proximity (sensor and system dependent)
which helps with the wake-up response time
of the system.
3.5.2 Low-Power in Normal Mode
If automatic mode is NOT selected, the
system will work as follows in Normal Mode
(possibly the hardware does not allow for a
ProxMode electrode):
After ModeTime of no prox, touch or snap, the
system will stay in Normal Mode, but all
channels will with a low-power duty cycle. If
an event is sensed on a Normal Mode
channel, full-speed charging will commence
immediately to provide fast response.
will
consumption as found in ProxMode, since
more channels are usually processed in
Normal
consumption (longer/more processing means
higher ratio of high current operation time
versus sleep time).
3.5.3 Low-Power in ProxMode
If automatic mode is NOT selected, and the
system is in ProxMode charging:
After a period of ModeTime of no PROX on
the ProxMode sensor, the ProxMode channel
will charge in the low-power mode. If a PROX
is sensed on this channel, it will stay in
ProxMode, and will charge at full-speed.
3.6 Data Report Rate
The report rate of the device depends on the
charge transfer frequency, number of enabled
channels, and the count value of the channels.
The length of communications initiated by the
master device will also affect the report rate.
There is a maximum rate governed by the
time taken to process the data, but the rate
Revision 1.04
Series
®
not
provide
Mode,
the
thus
same
increasing
low
November 2012
Page 9 of 50
power
This
the