at42qt2100 ATMEL Corporation, at42qt2100 Datasheet - Page 7

• Manufacturer Part Number: at42qt2100
• Description: Qtouch Touch Sensor Ic
• Manufacturer: ATMEL Corporation

2.7
9554CX–AT42–11/11
Operating Modes
The device features a number of operating modes to set the current drain and speed of
response.
The available operating modes are:
• Free Run Mode
• LP Mode
• Sleep Mode
• Sync Mode
This mode uses a continuous stream of acquire bursts. Free Run mode has, in
consequence, the highest power drain of all the QT2100 operating modes but the fastest
response time.
In LP (low power) modes, the QT2100 spends a portion of the time sleeping to conserve
power; it wakes itself periodically to perform acquire bursts, then normally goes back to
sleep again. The QT2100 provides a choice of intervals between acquire bursts to allow an
appropriate trade-off between speed and power to be made for each product.
In Sleep mode, the QT2100 shuts down to conserve power; it remains in this mode,
carrying out no acquisition bursts until the host wakes it using the SS pin.
In this mode the device synchronizes to the host in a way that allows for the suppression of
heavy low frequency noise; for example, from mains frequencies and their harmonics.
AT42QT2100
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