ADS7843E - 12-Bit Resistive Touch Controller | Texas Instruments
Teilenummer: ADS7843E ✓ AktivADS7843E Übersicht
A resistive touchscreen controller is an ADC-and-switch combination that measures voltage ratios from a four-wire touch panel. The ADS7843E belongs to the analog-to-digital converter hierarchy, where the ADC digitizes the touch-panel voltage and the synchronous serial interface transfers conversion results to a host processor. Its ratiometric conversion method allows the reference voltage to vary from 1 V to VCC, producing a corresponding input range from 0 V to VREF.
Key features include programmable or 12-bit resolution, two auxiliary analog inputs, a four-wire resistive touch-screen interface, and full power-down control. The 125 kHz conversion capability supports responsive touch sampling while the ratiometric measurement approach helps compensate for supply and reference variations. The 16-pin SSOP format also supports compact, surface-mount touchscreen modules.
Internally, the controller combines switched inputs, a sampling ADC, a reference path, and a synchronous serial interface. The low-on-resistance switches reduce the load presented to the touch panel, while the auxiliary inputs let the host monitor additional analog signals through the same converter. Conversion results are transferred through the serial interface, allowing the ADS7843E to operate as a peripheral to a microcontroller or embedded controller.
Typical applications include four-wire resistive touchscreen panels in industrial HMIs, portable instruments, test equipment, medical-device interfaces, and compact embedded control panels. The 12-bit resolution supports touch-position calculations across a typical X-Y panel, while the 125 kHz sampling rate can be adapted to the host interface and required response time.
When connecting the touch panel, maintain the recommended analog layout and route the touch, reference, and serial signals to minimize interference. Select output data rate, reference voltage, and auxiliary-channel multiplexing in software according to the host sampling rate and control-panel responsiveness.
This page combines the manufacturer specifications with practical interface guidance, sourcing paths, and a parameter comparison for engineers evaluating touch-screen controllers. It focuses on the ADS7843E itself rather than treating the different order codes as functionally distinct designs.
Drop-in-Alternativen für ADS7843E – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
ADS7843EG4
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
ADS7843E Grenzwerte & elektrische Eigenschaften
| ADC Resolution | 12 bit |
| Conversion Rate | 125 kHz |
| Typical Power Dissipation | 750 uW at 125 kHz throughput and 2.7 V supply |
| Versorgungsspannung | 2.7 V single supply |
| Reference Voltage Range | 1 V to VCC |
| ADC Input Range | 0 V to VREF |
| Conversion Method | Ratiometric |
| Touch-Screen Interface | 4-wire resistive touch screen |
| Auxiliary Analog Inputs | 2 inputs |
| Serial Interface | Synchronous serial interface |
| Power-Down Control | Full power-down control |
| Programmable Resolution | Programmable or 12-bit resolution |
| Gehäuse | 16-pin SSOP |
| Montageart | Surface mount |
| Betriebstemperaturbereich | -40 C to 85 C |
| RoHS-Status | Compliant |
ADS7843E 16-pin ssop Pinbelegungsleitfaden
Pinbelegung für ADS7843E (16-pin ssop-Gehäuse). Dieses analoge Bauteil verfügt über Eingangs-, Ausgangs- und Versorgungspins. Offset-Null-, Kompensations- und Enable-Pin-Konfigurationen entnehmen Sie dem Herstellerdatenblatt. Ideal für Signalaufbereitung und Verstärkerschaltungen.
Keine detaillierten Pinbelegungsdaten verfügbar für ADS7843E.
Siehe die Datenblatt für die vollständige Pin-Konfiguration.
Typische Anwendungen
ADS7843E ist geeignet für 6 Anwendungs: Industrial Human-Machine Interfaces, Portable Test and Measurement Instruments, Medical Device Touch Panels, Embedded Control and Diagnostics, Data Acquisition and Calibration Panels, IoT Appliance User Interfaces.
Industrial Human-Machine Interfaces
The ADS7843E suits industrial control panels using a four-wire resistive touch screen because its 12-bit conversion resolution and 125 kHz sampling rate provide responsive position data. Its integrated low-on-resistance switches reduce the loading applied to the panel, while ratiometric conversion supports measurements referenced to an adjustable 1 V to VCC range. The device operates from a single 2.7 V supply and reports typical power dissipation of 750 uW at maximum throughput. A host microcontroller can poll the synchronous serial interface, select the required panel axis, and apply calibration coefficients stored in nonvolatile memory.
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Portable Test and Measurement Instruments
The ADS7843E is appropriate for handheld analyzers, meters, and calibration instruments with a four-wire resistive display. Its 125 kHz conversion rate supports rapid touch sampling, while the 12-bit result provides adequate granularity for defining menu selections and instrument controls. The 2.7 V single-supply operation can simplify low-voltage portable architectures, and full power-down control is useful when the instrument is inactive. Designers should set the conversion rate to balance touch responsiveness against the 750 uW maximum-throughput dissipation figure and use the two auxiliary inputs for other slow-changing analog measurements when panel resources are not in use.
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Medical Device Touch Panels
The ADS7843E can support four-wire resistive touch panels in medical equipment where a dedicated touch digitizer is unnecessary. Its 12-bit sampling ADC provides enough resolution for menu navigation, and the ratiometric conversion method couples the measurement to the reference path, which helps reduce errors from shared voltage variation. The single 2.7 V supply requirement and 16-pin SSOP package fit compact control boards. For connected or life-critical equipment, confirm the final product's electrical-safety, EMC, and qualification requirements independently because the ADS7843E's component-level RoHS status does not establish system compliance.
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Embedded Control and Diagnostics
The ADS7843E is useful in embedded diagnostic equipment that combines a touch display with additional analog measurements. Its two auxiliary analog inputs can sample sensors or status signals when the touch panel is idle, reducing the number of separate ADC packages required in a compact design. The controller's 125 kHz conversion capability supports rapid panel sampling, and the 12-bit resolution supports proportional and calibration-based touch-position calculations. The host should time the serial transactions and auxiliary-channel multiplexing, keep analog routing short, and use full power-down control during long inactive periods to reduce system energy use.
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Data Acquisition and Calibration Panels
The ADS7843E fits data-acquisition front ends that use an operator touch interface to select ranges, channels, and calibration parameters. Its 125 kHz conversion rate allows rapid screen response, while programmable resolution can balance host bandwidth and power use. The reference may be varied from 1 V to VCC, enabling the analog front end to match the excitation and measurement range of the touch panel. Engineers should perform endpoint, linearity, and offset calibration for both screen axes, include the two auxiliary inputs only after confirming their acquisition timing, and place the analog and serial interfaces according to the manufacturer layout guidance.
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IoT Appliance User Interfaces
The ADS7843E can add a local four-wire resistive touch interface to connected appliances and compact IoT control equipment. Its 2.7 V single-supply operation is compatible with low-voltage embedded systems, and the 125 kHz sampling rate is sufficient for responsive menu input. Because the device is a peripheral rather than a complete user-interface processor, the host must handle debouncing, coordinate mapping, calibration, and communication with the application processor. Full power-down control provides a defined low-power state during inactivity, while the auxiliary inputs can reduce peripheral count when additional status signals must be digitized.
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Zusammenfassung der empfohlenen Produkte
Technische Referenzdaten für ADS7843E – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt | ADS7843EG4 |
|---|---|---|
| Package | 16-SSOP | 16-SSOP |
| Brand | Texas Instruments | Texas Instruments |
| ADC Resolution | 12 bit | 12 bit |
| Conversion Rate | 125 kHz | 125 kHz |
| Typical Power Dissipation | 750 uW at 125 kHz throughput and 2.7 V supply | 750 uW at 125 kHz throughput and 2.7 V supply |
| Reference Voltage Range | 1 V to VCC | 1 V to VCC |
| ADC Input Range | 0 V to VREF | 0 V to VREF |
| Touch-Screen Interface | 4-wire resistive touch screen | 4-wire resistive touch screen |
Wichtigste Unterscheidungsmerkmale
- High sampling rate for a compact resistive-touch digitizer (vs. ADS7843EG4)
- Simplified monitoring architecture for designs without battery sensing (vs. ADS7846E)
- Two auxiliary analog inputs extend measurement capability (vs. ADS7843EG4)
Designhinweise
Route the touch-panel inputs and reference network as a compact analog section. Keep the ADS7843E close to the touch connector, place the manufacturer's recommended input and reference capacitors at the associated pins, and avoid routing sensitive touch signals beside the synchronous serial clock. Review the pin-description and layout sections in the manufacturer datasheet before fixing the PCB footprint, because generic SSOP drawings do not show the complete analog pin grouping.
Design the 2.7 V supply path for both the touch controller and the host system. Place local high-frequency bypass capacitance at the device supply pins and keep the return current close to the analog ground reference. The stated 750 uW figure applies at 125 kHz throughput and a 2.7 V supply; use full power-down control when the panel is inactive, and calculate the total load with the supply voltage, converter efficiency, and host activity included.
Do not assume that two controllers in the same SSOP footprint are interchangeable. ADS7846E adds temperature and battery monitoring and changes reference and supply requirements, while ADS7841-family devices have different auxiliary-channel arrangements. Before any substitution, compare every pin, the allowable VREF range, serial timing, conversion mode, and power-down state against the existing schematic. Perform touch calibration and axis-accuracy checks after replacing the device.
Compliance-Informationen
The part listing identifies ADS7843E as RoHS compliant. No automotive qualification, lead-free status, halogen-free status, REACH status, or conflict-minerals statement is confirmed for the exact order code.