[AK4185]
AK4185
Low Power Touch Screen Controller with SPI™ Interface
GENERAL DESCRIPTION
The AK4185 is a 4-wire/ 5-wire resistive touch screen controller that incorporates 12bit SAR A/D
converter. The AK4185 operates down to 1.6V supply voltage in order to connect a low voltage
microprocessor. The AK4185 has both an automatic continuous measurement and a measurement data
calculation function. The functions that normally require external processing, such as calculating the
average screen input value, are processed by the AK4185. In addition, a new sequential mode achieves
short coordinate measurement time while greatly reducing the microprocessor overhead. The AK4185
can detect the pressed screen location by performing two A/D conversions and it can also measure touch
pressure. The AK4185 is the best fit for cellular phone, DSC, DVC, smart phone, or other portable
devices.
FEATURES
4-wire or 5-wire Touch Screen Interface
SPI
TM
Serial Interface
12bit SAR A/D Converter with S/H circuit
Sampling Rate: 300Ksps
Pen Pressure Measurement (4-wire)
Continuous Read Function (External Clock Mode)
Integrated Internal Osc (Sequence Mode)
Integrated Median Averaging Filter
Low Voltage Operation: VDD = 1.6V ~ 3.6V
PENIRQN Buffer Output
Low Power Consumption: 240μA at 1.8V
Auto Power Down
Package: 12pin CSP (1.96mm x 1.46mm, pitch 0.5mm)
Software Compatible with AK4182A
VDD
XP/BR
YP/TR
XN/TL
YN/BL
IN/
WIPER
TEMP
Internal
Osc
CSN
4/5wire
Touch
Screen
Drivers
Interface
SPI
Serial I/F
&
Control
Logic
DIN
SCLK
DOUT
PENIRQN
VREF+
AIN+
MUX
AIN-
SAR
ADC
VREF-
VSS
Figure 1. Block Diagram
SPI
TM
is a registered trademark of Motorola, Inc.
MS0954-E-05
-1-
2010/10
AKM [ ASAHI KASEI MICROSYSTEMS ]
