General Description

The MK715 Touch Screen Controller IC provides all the screen drive, Analog to Digital converter (ADC) and control circuits to easily interface to 4-wire analog resistive touch screens. It also includes a general purpose A to D converter and a clock synthesizer.

Features

• Tiny 20 pin SSOP (150 mil body)

• 4 microamp standby current

• Less than 3mA active current at 3.3V, including screen drive

• Touch pressure can be measured

• One or two general purpose A to D inputs

• On-chip voltage reference

• 32.768kHz crystal/clock input

• MHz clock outputs available

• Operates with four wire touch screens

• Ratiometric conversion eliminates screen calibration

• Automatic wake up upon screen touch

• Programmable conversion rate to a maximum of 303 points per second

• 3.3V or 5V supply (2.7V version available)

• 10 bit A/D converter

• Full powerdown control

• Touch screen is directly driven - no external transistors are required

• A to D Converter guaranteed monotonic

• 3 or 4 wire serial interface

Applications

• Notebook Computers

• Handheld Computers

• PDAs

• Touch-screen kiosks