Datasheet

27
9502A–AT42–07/08
AT42QT2160
7.10 Address 11: Reset
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
I
2
C-compatible
communications and make CHANGE
inactive within 16ms. The chip will reset after another
~16ms.
7.11 Address 12: LP Mode
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 Section 4.17 on page 13).
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 Table 10-1 on page 45 for typical power consumptions.
Default value: 1 (6ms LP)
7.12 Address 13: Burst Repetition
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)
Table 7-10. Reset
Addressb7b6b5b4b3b2b1b0
11 RESET
Table 7-11. LP Mode
Addressb7b6b5b4b3b2b1b0
12 LP_MODE
Table 7-12. Burst Repetition
Addressb7b6b5b4b3b2b1b0
13 0 0 BREP