3.
User Guide
3.1
Powering the Board
The kit is powered from the micro-USB connector. The kit can be powered by connecting the micro-USB
cable to the USB connector on the board and to the computer.
On initial power-up, the QT1010 requires approximately 100 ms to power on, to allow power supplies to
stabilize. During this time, the OUT-pin state is not valid and should be ignored.
3.2
Operation Modes
The kit operates in three different operation modes, which depend on the state of the SYNC pin (High or
Low).
3.2.1
Fast Mode
The QT1010 runs in Fast mode if the SYNC pin is permanently high. In this mode, the QT1010 runs at
maximum speed at the expense of increased current consumption. Fast mode is useful when speed of
response is the prime design requirement. The delay between bursts (= touch scans) in Fast mode is
approximately 1 ms.
3.2.2
Low-Power Mode
The QT1010 runs in Low-Power (LP) mode if the SYNC pin is held low. In this mode, it sleeps for
approximately 80 ms at the end of each burst, saving power but slowing response. On detecting a
possible key touch, it temporarily switches to Fast mode until either the key touch is confirmed or found to
be spurious (via the detect integration process). It then returns to LP mode after the key touch is
resolved.
3.2.3
Sync Mode
It is possible to synchronize the device to an external clock source by placing an appropriate waveform
on the SYNC pin. SYNC mode can synchronize multiple QT1010 devices to each other to prevent cross-
interference, or it can be used to enhance noise immunity from low-frequency sources such as 50 Hz or
60 Hz mains signals. The SYNC pin is sampled at the end of each burst.
AT42QT1010
User Guide
©
2018 Microchip Technology Inc.
User Guide
DS40002062A-page 5
