at42qt1040 ATMEL Corporation, at42qt1040 Datasheet - Page 9

• Manufacturer Part Number: at42qt1040
• Description: Qtouch? 4-key Sensor Ic
• Manufacturer: ATMEL Corporation

4.3
9524B–AT42–04/09
Speed Selection
Figure 4-1.
Speed selection is determined by a 1 M resistor (RFS resistor) connected between SNSK1
and either Vdd (Fast Mode) or Vss (Slow Mode).
Table 4-2.
In Fast Mode, the device sleeps for 16 ms between burst acquisitions. In Slow Mode, the device
sleeps for 64 ms between acquisitions. Hence, Slow Mode conserves more power but results in
slightly less responsiveness.
Note:
RFS Connected To...
Vdd
Vss
The RFS resistor should always be connected to either Vdd or Vss and not changed
during operation of the device. Changing the RFS option will affect the sensitivity of the
particular key. Always check that the sensitivity is suitable after a change. Retune Cs1 if
necessary.
~500 ns Pulse On OUT2 Pin
RFS Resistor
SNS0K
OUT2
SNS0K
OUT2
Power-on/
Reset
~20 ms
Mode
Fast mode
Slow mode
Pulse on OUT2
AT42QT1040
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