ADS7846AN

Overview

The ADS7846AN is a 12-bit resolution resistive touch screen controller manufactured by Texas Instruments, succeeding the industry-standard ADS7843. It operates on a single supply voltage ranging from 2.2V to 5.25V and features a 3-wire SPI/QSPI serial interface with a throughput rate of 125 kSPS. The device integrates an internal 2.5V reference, battery monitoring (0V to 6V), on-chip temperature sensing, and touch-pressure measurement capabilities. Designed for low-power applications, it consumes less than 0.75mW at 2.7V with the reference off. It supports automatic power-down modes and is specified for industrial temperatures between -40°C and +85°C.

Feature Summary

• 100% pin-compatible with ADS7843, enabling direct socket replacement with software updates only.
• Integrates an internal 2.5V reference that can be powered down to conserve energy.
• Supports direct battery voltage measurement (0V to 6V) and on-chip temperature sensing.
• Features a 3-wire serial interface compatible with standard SPI protocols.

Applications

• Personal Digital Assistants (PDAs)
• Portable Instruments
• Point-of-Sale Terminals
• Cellular Phones

Procurement Notes

Verify the specific package designation for the 'AN' suffix, as datasheet ordering tables list SSOP-16 (ADS7846N) and TSSOP-16 (ADS7846E) variants. Confirm current production status and lead times directly with Texas Instruments or authorized distributors, as availability may vary by region.

Selection Notes

Select this component for systems requiring a drop-in upgrade from ADS7843 designs. Ensure the host microcontroller supports the required 3-wire serial timing. Verify that the system voltage remains within the 2.2V to 5.25V operating range and that the application benefits from the integrated battery and temperature monitoring features.

Part Context

The ADS7846 series represents a next-generation evolution of the ADS7843 touch screen controller. While maintaining identical pinouts for legacy compatibility, it adds significant functionality including pressure detection and auxiliary input channels. The family includes various package options such as SSOP, TSSOP, QFN, and VFBGA to suit different PCB space constraints.

Replacement Considerations

The ADS7846 is a direct functional replacement for the ADS7843 in existing hardware layouts. No PCB modifications are required due to 100% pin compatibility. Implementation requires updating firmware to utilize new features like battery monitoring or pressure sensing if desired.