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The image-sensing area of the TC277 is configured into 288 lines with 699 elements in each line. Thirty-three elements are provided in each line for dark reference. The blooming-protection feature 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 device can also be run as a 732 (H) by 288 (V) noninterlaced sensor with significant reduction in the dark signal. The image is read out through three outputs, each of which reads out every third column.

A gated floating-diffusion detection structure with an automatic reset and voltage reference incorporated on-chip converts charge to signal voltage. A low-noise, two-stage, source-follower amplifier buffers the output and provides high output-drive capability.

The TC277 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 TC277 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 PAL B/W TV Applications
• 8-mm Image-Area Diagonal, Compatible With 1/2" Vidicon Optics
• 699 (H) x 288 (V) Active Elements in Image-Sensing Area
• Low Dark Current
• Electron-Hole Recombination Antiblooming
• Dynamic Range . . . More Than 70 dB
• High Sensitivity
• High Photoresponse Uniformity
• High Blue Response
• Single-Phase Clocking
• Solid-State Reliability With No Image Burn-in, Residual Imaging, Image Distortion, Image Lag, or Microphonics