DATASHEET
TOUCH SCREEN CONTROLLER MK712
IDT™
TOUCH SCREEN CONTROLLER 1
MK712 REV M 122109
Description
The MK712 Touch Screen Controller IC provides all the
screen drive, A to D converter and control circuits to easily
interface to 4-wire analog resistive touch screens.
The IC continually monitors the screen waiting for a touch.
In this mode, the supply current is typically 0.5µA. 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 197 times per
second until no further screen touches are detected, at
which time the low current mode is resumed.
Block Diagram
Features
• Packaged in 28-pin SSOP (150 mil) or 28-pin SOIC (300
mil)
• Industrial (-30°C to +70°C) and commercial (0 to +70°C)
and automotive (-35°C to +85°C) temperature ranges
• Available in Pb (lead) free
• Fully integrated, lowest power solution
• Low standby current of 0.5µA (typical) at 5.0 V
• Active current while converting less than 10 mA
• Resolves 350 dots/inch on 10.5” display
• Maximum speed of 197 points/second
• Ratio metric conversion may eliminate screen calibration
• Automatically wakes up and goes back to standby
• 3.3 V or 5 V supply
• 12 bit A/D converter
• Simplifies the writing of software for touch screens
• Extended temperature range available
• Capacitors are the only external components required
• Touch screen is directly driven - no external transistors
are required
• Programmable conversion rate
• A to D Converter is monotonic
• Parallel interface
NOTE: EOL for non-green parts to occur on 5/13/10
per PDN U-09-01
Pin Assignment
18
7
17
8
16
9
15
XL
10
YH
11
YL
12
GND
13
GND
14
GND
D6
D7
CLKIN
WR
A0
A2
RD
A1
22
21
20
19
CS
VDD
5
6
VDD
XH
D5
24
23
D4
3
4
TOUCH
VDD
D3
26
25
D2
1
2
NC
INT
D1
28
27
D0
