Texas Instruments AFE2256TDU

Description
The AFE2256 is a 256-channel analog front-end (AFE) designed for flat-panel detector (FPD) based digital x-ray systems. It includes 256 integrators, a programmable gain amplifier (PGA), a correlated double sampler (CDS), 256:4 analog multiplexers, and four 16-bit successive-approximation register (SAR) analog-to-digital converters (ADCs). Serial data from the ADCs is available in low-voltage differential signaling (LVDS) format. Hardware-selectable integration polarity allows positive or negative charge integration. The Nap feature enables substantial power saving.

Features
256 channels
On-chip, 16-bit ADC
Photodiode short immunity
Column short immunity
High performance:
Noise: <800 e-RMS with 50-pF sensor capacitance in 1.2-pC input range
Integral nonlinearity: 5 LSB with internal 16-bit ADCs
Scan time:
20 us in non-binning mode
15 us in 2 x 2 binning mode
Integration:
Six selectable full-scale input ranges: 0.6 pC (min) to 9.6 pC (max)
Internal timing generator (TG)
Built-in correlated double sampler
2 x 2 binning mode (averages charge of two adjacent channels) for faster throughput
Pipelined integrate and read: allows data read during integration
Serial LVDS output
Flexibility:
Electron and hole integration
Simple power-supply scheme:
AVDD1 = 11.85 V
AVDD2 = 3.3 V
Low power:
<2 mW/ch
<0.05 mW/ch in Nap mode
Total power-down
Chip-on-film (COF) package

Applications
Flat-panel, X-ray detectors
Charge detectors