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AD7843:  Touch Screen Digitizer

Product Details

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. View the QSOP Package Dimensions. (pdf, 19,569 bytes)

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.


  • 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

Functional Block Diagram for AD7843


Title Content Type File Type
AD7843: Touch Screen Digitizer Data Sheet (Rev B, 03/2004) (pdf, 271 kB) Data Sheets PDF
AN-577: Layout and Grounding Recommendations for Touch Screen Digitizers  (pdf, 52 kB) Application Notes PDF
UG-062: Evaluation Board for AD7843/AD7873 Resistive Touch Screen Controllers  (pdf, 334 kB) User Guides PDF
The PDA Challenge—Met by the AD7873 Resistive-Touch-Screen Controller ADC
(Analog Dialogue, Vol. 35, No. 4, August-September, 2001)
Analog Dialogue HTML
MS-2210: Designing Power Supplies for High Speed ADC  (pdf, 327 kB) Technical Articles PDF
RAQs index Rarely Asked Questions HTML
Glossary of EE Terms Glossary HTML

Design Tools,Models,Drivers & Software

Title Content Type File Type
AD7873 Input Touch Screen Digitizer Linux Driver Device Drivers HTML

Evaluation Kits & Symbols & Footprints

Symbols and Footprints— Analog Devices offers Symbols & Footprints which are compatible with a large set of today’s CAD systems for broader and easier support.

SampleSample & Buy

Price, packaging, availability

AD7843 Model Options
Model Package Pins Temp.
Price*(100-499) Price*1000 pcs RoHS View PCN/ PDN Check Inventory/
AD51/064Z-0REEL Status: Production 16 ld TSSOP 16 Comm. Reel, 2500 - - Y  Material Info PCN Contact ADI
AD7843ARQZ Status: Production 16 ld QSOP 16 Comm. Tube, 98 $1.29 $1.16 Y  Material Info PCN Purchase Sample
AD7843ARQZ-REEL Status: Production 16 ld QSOP 16 Comm. Reel, 2500 - $1.16 Y  Material Info PCN Purchase
AD7843ARQZ-REEL7 Status: Production 16 ld QSOP 16 Comm. Reel, 1000 - $1.16 Y  Material Info PCN Purchase
AD7843ARUZ Status: Production 16 ld TSSOP 16 Ind Tube, 96 $1.29 $1.16 Y  Material Info PCN Purchase Sample
AD7843ARUZ-REEL7 Status: Production 16 ld TSSOP 16 Ind Reel, 1000 - $1.16 Y  Material Info PCN Purchase
Price Table Help

The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

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