[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

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: 240

μA at 1.8V

Auto Power Down

Package: 12pin CSP (1.96mm x 1.46mm, pitch 0.5mm)

Software Compatible with AK4182A

PENIRQN

SPI

Serial I/F

&

Control

Logic

CSN

VSS

AIN+

AIN-

DOUT

DIN

SCLK

XP/BR

YP/TR

XN/TL

YN/BL

IN/

WIPER

SAR

ADC

VDD

4/5wire

Touch

Screen

Drivers

Interface

MUX

TEMP

VREF+

VREF-

Internal

Osc

Figure 1. Block Diagram

MS0954-E-05

2010/10

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