AK4186 AKM [Asahi Kasei Microsystems], AK4186 Datasheet - Page 29

• Manufacturer Part Number: AK4186
• Description: Low Power Touch Screen Controller with I2C Interface
• Manufacturer: AKM [Asahi Kasei Microsystems]

AK4186EN <5-wire Touch Screen Input>
1. Grounding and Power Supply Decoupling
The AK4186 requires careful attention to power supply and grounding arrangements. VDD is usually supplied from the
system’s analog supply. VSS of the AK4186 must be connected to the analog ground plane. System analog ground and
digital ground should be connected together near to where the supplies are brought onto the printed circuit board.
Decoupling capacitors should be as near to the AK4186 as possible, with the small value ceramic capacitor being the
nearest.
2. Analog Inputs
When an EMI source is close to the touch panel analog signal line, EMI noise affects analog characteristics
performance. Connect noise canceling capacitors (*) as close as possible to each pin (XP, XN, YP, YN pins) of the
AK4186 to avoid this noise.
MS1068-E-04
Notes:
- VSS of the AK4186 should be distributed separately from the ground of external controllers.
- All digital input pins (SCL, SDA, CAD0 pins) must not be left floating.
Digital Ground
µP
(Figure
Rp
Figure 38. Typical Connection Diagram (5-wire, AK4186EN)
Analog Ground
35,
Figure
Rp
13
14
15
16
36,
VSS
T EST
N C
NC
AK4186EN
Figure
Top View
Touch Screen
- 29 -
5-wire
37,
Figure
WIPER
VDD
NC
NC
38)
8
7
6
5
“L” or “H”
0.001µ *
0.1µ
0.001µ *
0.001µ *
0.001µ *
0.001µ *
+
10µ
Analog Supply
1.6∼3.6V
[AK4186]
2011/03