Audioaccess MA-361 Service, Service Manual

Page: 57 / 110

FEATURES
●
SAME PINOUT AS ADS7843
●
2.2V TO 5.25V OPERATION
●
INTERNAL 2.5V REFERENCE
●
DIRECT BATTERY MEASUREMENT (0V to 6V)
●
ON-CHIP TEMPERATURE MEASUREMENT
●
TOUCH-PRESSURE MEASUREMENT
●
QSPI/SPI 3-WIRE INTERFACE
●
AUTO POWER DOWN
●
TSSOP-16 AND SSOP-16 PACKAGES
APPLICATIONS
●
PERSONAL DIGITAL ASSISTANTS
●
PORTABLE INSTRUMENTS
●
POINT-OF-SALES TERMINALS
●
PAGERS
●
TOUCH-SCREEN MONITORS
●
CELLULAR PHONES
TOUCH-SCREEN CONTROLLER
DESCRIPTION
The ADS7846 is a next-generation version to the industry
standard ADS7843 4-wire touch-screen controller. The
ADS7846 is 100% pin-compatible with the existing
ADS7843, and will drop into the same socket. This allows
for easy upgrade of current applications to the new ver-
sion. Only software changes will be required to take
advantage of the added features of direct battery measure-
ment, temperature measurement, and touch-pressure mea-
surement. The ADS7846 also has an on-chip 2.5V refer-
ence that can be utilized for the auxiliary input, battery
monitor, and temperature measurement modes. The refer-
ence can also be powered down when not used to conserve
power. The internal reference will operate down to 2.7V
supply voltage while monitoring the battery voltage from
0V to 6V.
The low power consumption of < 0.5mW typ at 2.7V
(reference OFF), high speed (> 125kHz clock rate), and
on-chip drivers make the ADS7846 an ideal choice for
battery-operated systems such as Personal Digital Assis-
tants (PDAs) with resistive touch screens, pagers, cellu-
lar phones, and other portable equipment. The ADS7846
is available in the small TSSOP-16 and SSOP-16 pack-
ages and is guaranteed over the –40
°
C to +85
°
C tem-
perature range.
ADS7846
CDAC
Internal 2.5V
Reference
SAR
ADS7846
Comparator
6-Channel
MUX
Serial
Data
Out
Temperature
Sensor
Battery
Monitor
DOUT
BUSY
CS
DCLK
DIN
V
BAT
AUX
V
REF
+V
CC
X+
X–
Y+
Y–
PENIRQ
ADS7846
SBAS125A – APRIL 2001
www.ti.com
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters. Copyright © 1999, Texas Instruments Incorporated
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.