DVC DigitEyes Series, Technical Manual, Page: 12 / 66

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The Image Sensing area of the TC-245 is configured into 242 lines with 786 elements in each
line. 29 elements are provided in each line for dark reference. The blooming protection feature of
the sensor is based on recombining excess charge with charge of opposite polarity in the
substrate. This Anti-blooming is activated by supplying clocking pulses to the anti-blooming gate,
an integral part of each image-sensing element. The sensor is designed to operate in an
interlace mode, electronically displacing the image sensing elements in alternate fields by 1/2 of
a vertical line during the charge integration period, effectively increasing the vertical resolution
and minimizing aliasing. The device can also be operated as a 755(H) X 242(V) non-interlaced
sensor with significant reduction in the dark signal.
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 image is
readout through three outputs, each of which reads out every third image column.
The TC-245 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 TC-245 is
characterized for operation from -10°C to 45°C.
Figure 4-2: TC-245 Mechanical Drawing (

Texas Instruments, 1994)