AD7843 Touch Screen Digitizer

The AD7843 is a 12-bit successive-approximation ADC with a synchronous serial interface and low on resistance switches for driving touch screens. The part operates from a single 2.2 V to 5.25 V power supply and features throughput rates greater than 125 kSPS. The external reference applied to the AD7843 can be varied from 1 V to +VCC, while the analog input range is from 0 V to VREF. The device includes a shutdown mode that reduces the current consumption to less than 1 µA. This part is available in a 16-lead 0.15" Quarter Size Outline (QSOP) package and a 16-lead Thin Shrink Small Outline (TSSOP) package.

Also see the AD7843 sister part, which is the AD7873. This part is similar to the AD7843 but has added functionality such as an on-chip temperature sensor (-40°C to + 85°C), on-chip 2.5 V reference and direct battery and touch-pressure measurement.

Features and Benefits
  • 4-wire touch screen interface
  • Specified throughput rate of 125 kSPS
  • Low power consumption:
    1.37 mW max at 125 kSPS with VCC = 3.6 V
  • Single supply, VCC of 2.2 V to 5.25 V
  • Ratiometric conversion
  • High speed serial interface
  • Programmable 8-bit or 12-bit resolution
  • 2 auxiliary analog inputs
  • Shutdown mode: 1 µA max
  • 16-lead QSOP and TSSOP packages
Analog to Digital Converters
Data Sheets
Documentnote
AD7843: Touch Screen Digitizer Data Sheet (Rev. B)PDF 271 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
AD51/064Z-0REEL Production16 ld TSSOPREEL 2500-40 to 85C00Y
AD7843ARQZ Production16 ld QSOPOTH 98-40 to 85C1.291.16Y
AD7843ARQZ-REEL Production16 ld QSOPREEL 2500-40 to 85C01.16Y
AD7843ARQZ-REEL7 Production16 ld QSOPREEL 1000-40 to 85C01.16Y
AD7843ARUZ Production16 ld TSSOPOTH 96-40 to 85C1.291.16Y
AD7843ARUZ-REEL7 Production16 ld TSSOPREEL 1000-40 to 85C01.16Y
Reference Materials
AD7843: Touch Screen Digitizer Data Sheet (Rev. B) ad7843
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