AD7873 Touch Screen Digitizer

Ratiometric conversion mode available, eliminating errors due to on-board switch resistances. On-board temperature sensor: −40°C to +85°C. Battery monitor input. Touch pressure measurement capability. Low power consumption of 1.37 mW maximum with the reference off, or 2.41 mW typical with the reference on, at 125 kSPS and VCC at 3.6 V. Package options include 4 mm × 4 mm LFCSP. Analog input range from 0 V to VREF. Versatile serial I/O ports.

The AD7873 is a 12-bit successive approximation ADC with a synchronous serial interface and low on resistance switches for driving touch screens. The AD7873 operates from a single 2.2 V to 5.25 V supply, with a throughput rate of 125 kSPS.

The AD7873 features direct battery measurement, temperature measurement, and touch pressure measurement. The AD7873 also has an on-board reference of 2.5 V that can be used for the auxiliary input, battery monitor, and temperature measurement modes. When not in use, the internal reference can be shut down to conserve power. An external reference can also be applied and varied from 1 V to VCC with an analog input range from 0 V to VREF. The device includes a shutdown mode that reduces the current consumption to less than 1 µA.

The AD7873 features on-board switches. This, coupled with low power and high speed operation, makes the device ideal for battery-powered systems with resistive touch screens. The part is available in a 16-lead, 0.15 inch quarter size outline package (QSOP), a 16-lead, thin shrink small outline package (TSSOP), and a 16-lead, lead frame chip scale package (LFCSP).

Product Highlights

Applications

Features and Benefits
  • 4-Wire touch screen interface
  • On-chip temperature sensor:
    –40°C to +85°C
  • On-chip 2.5 V reference
  • Direct battery measurement (0 V to 6 V)
  • Touch pressure measurement
  • Specified throughput rate
    of 125 kSPS
  • Single supply, VCC of 2.2 V to 5.25 V
  • Ratiometric conversion
  • High speed serial interface
  • Programmable
    8- or 12-bit resolution
  • One auxiliary analog input
  • Shutdown mode: 1 µA maximum
  • 16-lead QSOP, TSSOP, and LFCSP packages
Analog to Digital Converters
Data Sheets
Documentnote
AD7873: Touch Screen Digitizer Data Sheet (Rev. F)PDF 579 kB
Application Notes
Documentnote
AN-577: Layout and Grounding Recommendations for Touch Screen Digitizers (Rev. 0)PDF 52 kB
User Guides
Documentnote
UG-062: Evaluation Board for AD7843/AD7873 Resistive Touch Screen ControllersPDF 334 kB
Order Information
Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
AD7873ACPZ Production16 ld LFCSP (4x4x.85mm, 2.10mm exposed pad)OTH 490-40 to 85C2.11.95Y
AD7873ARQZ Production16 ld QSOPOTH 98-40 to 85C2.11.95Y
AD7873ARQZ-REEL Production16 ld QSOPREEL 2500-40 to 85C2.11.95Y
AD7873ARQZ-REEL7 Production16 ld QSOPREEL 1000-40 to 85C2.11.95Y
AD7873ARUZ Production16 ld TSSOPOTH 96-40 to 85C2.11.95Y
AD7873ARUZ-REEL Production16 ld TSSOPREEL 2500-40 to 85C2.11.95Y
AD7873ARUZ-REEL7 Production16 ld TSSOPREEL 1000-40 to 85C2.11.95Y
AD7873BRQZ Last Time Buy16 ld QSOPOTH 98-40 to 85C2.11.95Y
AD7873BRQZ-REEL7 Last Time Buy16 ld QSOPREEL 1000-40 to 85C01.95Y
Reference Materials
AD7873: Touch Screen Digitizer Data Sheet (Rev. F) ad7873
AN-577: Layout and Grounding Recommendations for Touch Screen Digitizers (Rev. 0) ad7843
UG-062: Evaluation Board for AD7843/AD7873 Resistive Touch Screen Controllers ad7843
MS-2210:高速ADC的电源设计 ad9861