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The image-sensing area of the TC244A is configured into 242 lines with 786 elements in each line. Twenty-nine elements are provided in each line for dark reference. The blooming protection incorporated into the sensor is based on recombining excess charge with charge of opposite polarity in the substrate. This antiblooming is activated by supplying clocking pulses to the antiblooming gate, which is an integral part of each image-sensing element.

The sensor is designed to operate in an interlace mode, electronically displacing the image-sensing elements by one-half of a vertical line during the charge integration period in alternate fields, effectively increasing the vertical resolution and minimizing aliasing. The single-chip color-sensing capability of the TC244A is achieved by processing on striped color filter with RGB organization. The stripes are precisely aligned to the sensing elements, and the signal charge columns are multiplexed during the readout into three separate registers with three separate outputs corresponding to each individual color.

A gated floating-diffusion detection structure with an automatic reset and voltage reference incorporated on-chip converts charge to signal voltage. The signal is further processed by a low-noise, state-of-the-art correlated clamp-sample-and-hold circuit. A low-noise, two-stage, source-follower amplifier buffers the output and provides high output-drive capability.

The TC244A is built using TI-proprietary virtual-phase technology, which provides devices with high blue response, low dark signal, good uniformity, and single-phase clocking.

The TC244A is characterized for operation from -10°C to 45°C.

This MOS device contains limited built-in gate protection. During storage or handling, the device leads should be shorted together or the device should be placed in conductive foam. In a circuit, unused inputs should always be connected to SUB. Under no circumstances should pin voltages exceed absolute maximum ratings. Avoid shorting OUTn to ADB during operation to prevent damage to the amplifier. The device can also be damaged if the output terminals are reverse-biased and an excessive current is allowed to flow. Specific guidelines for handling devices of this type are contained in the publication Guidelines for Handling Electrostatic-Discharge-Sensitive (ESDS) Devices and Assemblies available from Texas Instruments.

• High-Resolution, Solid-State Image Sensor for NTSC Color TV Applications
• 8-mm Image-Area Diagonal, Compatible With 1/2" Vidicon Optics
• 755 (H) x 242 (V) Active Elements in Image-Sensing Area
• Advanced On-Chip Signal Processing
• Low Dark Current
• Electron-Hole Recombination Antiblooming
• Dynamic Range . . . More Than 70 dB
• High Sensitivity
• High Photoresponse Uniformity
• High Blue Response
• Single-Phase Clocking
• Separate Outputs for Each Color (RGB)
• Solid-State Reliability With No Image Burn-in, Residual Imaging, Image Distortion, Image Lag, or Microphonics