AFE2256TDT

Analog Front End (AFE) Overview

The AFE2256TDT is a 256-channel analog front-end (AFE) designed for digital X-ray flat-panel detectors. It integrates 256 integrators, a programmable gain amplifier, correlated double samplers, and four 16-bit SAR ADCs with LVDS outputs. Key electrical parameters include an input charge range of 0.6 pC to 9.6 pC, noise performance of 750 electrons RMS, and scan times from <20 µs to 204.8 µs. The device operates on AVDD1 = 1.85 V and AVDD2 = 3.3 V, featuring nap and power-down modes for low-power applications.

Analog Front End (AFE) Feature Summary

• 256 integrated channels with on-chip 16-bit SAR ADCs
• Photodiode short immunity and built-in correlated double sampling
• Pipelined integrate-and-read architecture for improved throughput
• Six selectable full-scale input ranges from 0.6 pC to 9.6 pC

Analog Front End (AFE) Applications

• Flat-panel X-ray detectors
• Charge detectors
• Capacitance measurement systems

Analog Front End (AFE) Procurement Notes

Verify the specific package suffix against the official orderable part list. The 'TDT' suffix does not appear in the current Texas Instruments documentation; available packages include TDR, TDU, and TBN. Confirm availability and exact physical dimensions before procurement to ensure compatibility with the target COF assembly.

Analog Front End (AFE) Selection Notes

Select based on required channel count and integration density. The AFE2256 supports pipelined data readout during integration, which increases system throughput. Ensure the application requires the specified 1.85 V and 3.3 V supply rails and that the photodiode short immunity meets the detector's safety requirements.

Analog Front End (AFE) Part Context

The AFE2256 belongs to the family of high-channel-count analog front-ends developed by Texas Instruments specifically for medical imaging. It replaces discrete signal conditioning components by integrating amplification, sampling, and conversion into a single custom Chip-On-Film (COF) solution optimized for space-constrained detector arrays.

Analog Front End (AFE) Replacement Considerations

Publicly confirmed substitute part numbers are not provided in the source material. Verify if legacy parts like the AFE0064 or AFE0256 meet the specific 256-channel requirement, noting differences in channel count and integration features.