AK4186 Datasheet, PDF (25/33 Pages) Asahi Kasei Microsystems – Low Power Touch Screen Controller with I2C Interface

[AK4186]
■ Pen Interrupt
The AK4186 has pen interrupt function to detect pen touches. Pen interrupt function is enabled at power-down state and
PD0 bit = “0” (Figure 34). The YN pin (4-wire) or BL pin (5-wire) is connected to VSS at the PEN interrupt enabled
state. The XP pin (4-wire) or WIPER pin (5-wire) is pulled up via an internal resistor (R_IRQ: typ.50kΩ). PENIRQN is
connected to the XP pin (4-wire) or WIPER pin (5-wire) inside. If touch plate is pressed by a pen, the current flows via
<VDD> - <Ri> - <X+> - <Y-> (4-wire). If 5-wire, via <VDD> - <Ri> - <WIPER> - <BL>. The resistance of the plate
is generally 1kΩ or less, PENIRQN is forced to “L” level. If the pen is released, PENIRQN returns “H” level because
two plates are disconnected, and the current does not flow via two plates.
During an A/D conversion or Sequence measurement or when PD0 bit is set to “1”, the PENIRQN is “L” for all the
time in this period regardless of the touched/non-touched state.
While in single measurement mode, the pen interrupt function is disabled from the rising edge of 26th SCL to the end of
the measurement. (Figure 28)
It is recommended that the micro controller mask the pseudo-interrupts while the control command is issued or A/D
data is output.
VDD
R_IRQ =
50kΩ
VDD
EN2
Driver OFF
PENIRQN
VDD
XP/WIPER
EN1
Driver ON
YN/BL
Figure 34. PENIRQN Functional Block Diagram (WIPER does not have a driver.)
MS1068-E-04
- 25 -
2011/03