ADS7846

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
·QSPITM/SPITM 3-WIRE INTERFACE
·AUTO POWER-DOWN
·TSSOP-16, SSOP-16, QFN-16, AND VFBGA-48 PACKAGES


Application

·PERSONAL DIGITAL ASSISTANTS
·PORTABLE INSTRUMENTS
·POINT-OF-SALE TERMINALS
·PAGERS
·TOUCH SCREEN MONITORS
·CELLULAR PHONES


Pinout




Specifications

+V_CC to GND ........................................................ 0.3V to +6V
Analog Inputs to GND ............................. 0.3V to +V_CC + 0.3V
Digital Inputs to GND ...............................0.3V to +V_CC + 0.3V
Power Dissipation ...........................................................250mW
Maximum Junction Temperature ....................................+150°C
Operating Temperature Range ......................40°C to +85°C
Storage Temperature Range .......................65°C to +150°C
Lead Temperature (soldering, 10s) ..............................+300°C


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 drops into the same socket. This allows for easy upgrade of current applications to the new version. Only software changes are required to take advantage of the added features of direct battery measurement, temperature measurement, and touch-pressure measurement. The ADS7846 also has an on-chip 2.5V reference that can be used for the auxiliary input, battery monitor, and temperature measurement modes. The reference can also be powered down when not used to conserve power. The internal reference operates down to 2.7V supply voltage while monitoring the battery voltage from 0V to 6V.

The low-power consumption of < 0.75mW (typ at 2.7V, reference off), high speed (up to 125kHz clock rate), and onchip drivers make the ADS7846 an ideal choice for batteryoperated systems such as personal digital assistants (PDAs) with resistive touch screens, pagers, cellular phones, and other portable equipment. The ADS7846 is available in the small TSSOP-16, SSOP-16, QFN-16, and VFBGA-48 packages and is specified over the 40°C to +85°C temperature range.