AK4185_10 Datasheet, PDF (1/30 Pages) Asahi Kasei Microsystems – Low Power Touch Screen Controller with SPI™ Interface

[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
MS0954-E-05
4/5wire
Touch
Screen
Drivers
Interface
TEMP
MUX
VREF+
AIN+ _SAR
ADC
AIN-
VREF-
SPI
Serial I/F
&
Control
Logic
Internal
Osc
CSN
DIN
SCLK
DOUT
PENIRQN
VSS
Figure 1. Block Diagram
SPI^TM is a registered trademark of Motorola, Inc.
2010/10
-1-