MK715

ICS reserves the right to make changes in the device data identified in this publication

without further notice. ICS advises its customers to obtain the latest version of all device

data to verify that any information being relied upon by the customer is current and accurate.

MK715RevD020200

Touch Screen Controller

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.

The IC continually monitors the screen waiting for a

touch. In this mode, the supply current is typically 4µA.

When the screen is touched, the IC performs analog to

digital conversions to determine the location of the touch,

stores the X and Y locations in the registers, and issues

an interrupt. This process is repeated up to 303 times per

second until no further screen touches are detected, at

which time the low current mode is resumed.

The device has a general purpose input into the 10-bit

ADC, allowing for the measurement of other inputs such

as battery voltage. The MK715 can be powered from a

3.3V supply, and uses an inexpensive 32.768kHz watch

crystal as the input reference. An internal Phase-Lock

Loop clock synthesizer provides the high speed clock for

the ADC, and the option to have a clock output to drive

other digital chips in the system.

The tiny package is the same body size as the 14 pin

SOIC, with 25 mil spacings on the leads.

•

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

Pin Assignment

Applications

• Notebook Computers

• Handheld Computers

• PDAs

• Touch-screen kiosks

General Description

Features

MK715

20 pin SSOP

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

CS

CLKOUT

INT

VDD

X2

X1

GND

CAP2

CAP1

CAP3

SK

D0

DI

TOUCH#

XH

XL

YH

YL

PL

GP