Rainbow Electronics AT42QT1040 - Manual (Page 9)

9
9524A–AT42–03/09
AT42QT1040
Figure 4-1. ~500 ns Pulse On OUT2 Pin
4.3 Speed Selection
Speed selection is determined by a 1 M
 resistor (RFS resistor) connected between SNSK1
and either Vdd (Fast Mode) or Vss (Slow Mode).
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: 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.
Pulse on OUT2
SNS0K
OUT2
SNS0K
OUT2
~20 ms Power-on/
Reset
Table 4-2. RFS Resistor
RFS Connected To... Mode
Vdd Fast mode
Vss Slow mode