at42qt2160 ATMEL Corporation, at42qt2160 Datasheet - Page 27

• Manufacturer Part Number: at42qt2160
• Description: Qslide?, 16-key Qmatrix? Sensor Ic
• Manufacturer: ATMEL Corporation

7.10
7.11
7.12
9502A–AT42–07/08
Address 11: Reset
Address 12: LP Mode
Address 13: Burst Repetition
Table 7-10.
Table 7-11.
Table 7-12.
Any nonzero value will trigger the device to reset. After a reset, the device will revert to default
settings.
After receiving a reset command the QT2160 will start not acknowledging
communications and make CHANGE inactive within 16ms. The chip will reset after another
~16ms.
LP mode sets the sleep time between bursts. A higher value causes more sleep time between
acquisitions resulting in lower power consumption, but slower response time.
The values are between 1...255, with each incrementing the sleep time by 16ms steps. For
example, 1 = 16ms LP, 2 = 32ms LP, 3 = 48ms LP, etc.
A value of zero causes the device to enter an ultra-low power mode (SLEEP), where no
measurements are carried out (see
The QT2160 is designed to sleep as much as possible to conserve power.
Note: the longer the LP mode, the longer the response time at first touch. The response time for
the first touch includes the digital filter's settling time (a few measurement cycles) and the DI
process. Above 256ms LP mode the power consumption does not reduce as much, even with
longer LP mode durations. Refer to
Default value: 1 (6ms LP)
Burst Repetition (BREP) is a feature that enables the QT2160 to make multiple measurements
and take the average result; this improves the device’s ability to operate in noisy environments.
The number of burst repetitions can be reduced in low noise environments for faster response
time. The BREP value can range between 1...63 repetitions. Do not set to 0 because it is not
valid.
Default value:1 (one measurement burst)
Address
Address
Address
11
12
13
Reset
LP Mode
Burst Repetition
b7
b7
b7
0
b6
b6
b6
0
Section 4.17 on page
Table 10-1 on page 45
b5
b5
b5
b4
b4
b4
LP_MODE
RESET
13).
b3
b3
b3
for typical power consumptions.
BREP
b2
b2
b2
AT42QT2160
b1
b1
b1
I
2
C
-compatible
b0
b0
b0
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