AK4160 Datasheet, PDF (12/40 Pages) Asahi Kasei Microsystems – 16-channel Capacitive Touch Sensor IC

[AK4160]
■ Programmable Interrupt
A state change of a sense terminal or GPIO is notified to the host by the IRQ output. The output driver is selectable from
open-drain type and totem-pole type, and the activate polarity can be configured. The active condition of the IRQ pins is
user-selectable as follows.
1. State Change
2. Touch (State Change from release state to touch state at sense terminals)
3. Release (State Change from touch state to release state at sense terminals)
4. Measurement Execution (any states)
5. Input edge detection of GPIO
Three IRQ pins can be independently configured to different conditions. Several user applications can be supported by the
flexible configuration. The unused pin of IRQ pins can simply be configured as a GPIO pin.
■ Multi Touch
The AK4160 supports multi touch operation. The multi touch function can be controlled, improving operability of an
application by enabling and disabling.
· Multi Touch Enabled
The status register reflects a touch detection of each sense terminal directly. Update of the status register is independent
for each sense terminal. The state of a sense terminal is not influenced by the state of other sense terminals.
· Multi Touch Disabled
Update of the status register is executed singularly. This is for an application that expects a single touch. The user can
select a mode shown below.
1. Release ALL
In this mode, if some sense terminals are touched while all sense terminals are internally released, only the most
pushed sense terminal is detected as touched and other touched sense terminal statuses are not updated to touched.
(Their statuses remain as released, but internally they are judged as touched.) All sense terminals must be
released internally, for a new touch detection in this state.
2. Release CH
In this mode, if some sense terminals are touched while all sense terminals are internally released, only the most
pushed sense terminal is detected as touched and other touched sense terminal statuses are not updated to touched.
(Their statuses remain as released, but internally they are judged as touched.) The most pushed sense terminal
must be released internally, for a new touch detection in this state. When the most pushed sense terminal is
released, the status of second most pushed sense terminal is updated to touched.
This exclusive update (multi touch disabled) can independently be assigned to each sense terminal. However, Release
ALL or Release CH mode configuration is common to all sense terminals which are assigned as multi touch disabled.
“The most pushed sense terminal” means a sense terminal which has the biggest difference between measured and
reference values. If there was a tie for the biggest difference value, the state of the sense terminal which has the smallest
channel number will be changed. By the user setting, “a touched sense terminal with the smallest channel number” can be
chosen as the condition of Release CH mode instead of the “the most pushed terminal”.
MS1313-E-01
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2011/11