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 ...More
AD7843: Touch Screen Digitizer
Product Description
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.)
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
- 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
Diagrams
- Enlarge
- Symbols and Footprints
Functional Block Diagram for AD7843
Touch Screen Digitizer
Functional Block Diagram for AD7843
EVAL-CED - Converter Evaluation and Development (CED) Board
AD7682 - 16-Bit, 4-Channel, 250 kSPS PulSAR® ADC
AD7262 - True Differential, Dual, 1 MSPS, 14-Bit/12-Bit, 2-Channel SAR ADC With PGA
AD7949 - 14-Bit, 8-Channel, 250 kSPS PulSAR® ADC
| Part# | Res | Throughput Rate | # of Inputs | Operating Pwr Diss |
|---|---|---|---|---|
| AD7450 | 12 | 1MSPS | 1 | 1.3mW |
| AD7466 | 12 | 200KSPS | 1 | 900µW |
| AD7994 | 12 | 188KSPS | 4 | 6mW |
| AD7923 | 12 | 200KSPS | 4 | 7.5mW |
| AD7924 | 12 | 1MSPS | 4 | 13.5mW |
| AD7934 | 12 | 1.5MSPS | 4 | 16mW |
| AD7866 | 12 | 1MSPS | 4 | 24mW |
| AD7862 | 12 | 250KSPS | 4 | 75mW |
| AD7366 | 12 | 1MSPS | 4 | 88.8mW |
| AD7864 | 12 | 520KSPS | 4 | 120mW |
| AD9228-65 | 12 | 65MSPS | 4 | 510mW |
AD7843 Model Options
Help
- Pre-Release: The model has not been released to general production, but samples may be available.
- Production: The model is currently being produced, and generally available for purchase and sampling.
- Last Time Buy: The model has been scheduled for obsolescence, but may still be purchased for a limited time.
- Obsolete: The specific part is obsolete and no longer available. Other models listed in the table may still be available (if they have a status that is not obsolete).
For detailed drawings and chemical composition please consult our Package Site
- Commercial: 0 to +70 degrees Celsius
- Military : -55 to +125 degrees Celsius
- Industrial: Temperature ranges may vary by model. Please consult the datasheet for more information.
- Automotive: -40 to +125 degrees Celsius
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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