[AK4187]

MS1260-E-03

2013/01

- 12 -

The AK4187 has pen interrupt function to detect pen touches. (Figure 6). The YN pin is connected to VSS at the PEN

to the XP pin internally. If the touch plate is pressed by a pen, the current flows via <VDD> - <Ri> - <X+> - <Y->

(4-wire). The resistance of the plate is generally 1kΩ or less, PENIRQN is forced to “L” level. If the pen is released, the

PENIRQN pin returns “H” level because two plates are disconnected, and the current does not flow via two plates.

During Sequence measurement or calculations, the pen interrupt function is disabled, and the PENIRQN pin is operated as

“Busy” signal. While in sleep mode, the pen interrupt function is disabled, and the PENIRQN pin is “H” or “Hi-z”. (Refer

to Table 10. Sleep Mode)

It is recommended that the micro controller masks the pseudo-interrupts while the sequence measurement is busy.

XP

PENIRQN

Driver ON

YN

EN

50k

Ω

Driver OFF

EN

VDD

VDD

1

0

Sleep

Busy

Figure 6. PENIRQN Function Block Diagram