The TC217 is a frame-transfer charge-coupled-device (CCD) image sensor with two field memories. It is suitable for use in NTSC video or still-picture photography applications. Its image-sensing area is configured into 488 lines; 486 of these are active and the remaining two are used for dark reference. Each line is configured into 1158 pixels with 1134 active and 24 for dark reference. The TC217 has a standard aspect ratio of 4:3 and a standard 11-mm image-sensing-area diagonal. Its blooming protection, which is an integral part of each pixel, is based on electron-hole recombination and is activated by clocking the antiblooming gate. One important aspect of the TC217 high-resolution sensor is its ability to simultaneously capture both fields of a TV frame. Its two independently addressable memories allow separate storage of each field and operation in a variety of modes, including EIA-170 (formerly RS-170) with true interlace, EIA-170 with pseudointerlace, and nonstandard pseudointerlace with a resolution of 972 lines. A unique multiplexer section (see Figure 3) rearranges the horizontal pixels into vertical groups of three and separates and loads the image into the two field memories. The independent addressing of each field memory provides flexibility for different modes of operation. The interdigitated layout of the memories allows each memory to share the same bank of three serial registers and associated charge detection amplifiers (see Figure 4 and the functional block diagram). Each register and associated amplifier reads out every third column of the image area (see Figure 5). The three amplifiers are optimized dual source-followers that allow the use of off-chip double-correlated clamp-sample-and-hold amplifiers for removing KTC noise. The TC217 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 TC217 is characterized for operation from 10C to 40C.