TC255P

336-

× 244-PIXEL CCD IMAGE SENSOR

SOCS057 – JUNE 1996

Copyright

2-1

POST OFFICE BOX 655303

Sensor for Low-Cost B/W TV Applications

Sensing Area

1/60–1/50000 s

Burn-In, Residual Imaging, Image

Distortion, Image Lag, or Microphonics

description

The TC255P is a frame-transfer charge-coupled device (CCD) designed for use in B/W NTSC TV and special-

purpose applications where low cost and small size are desired.

The image-sensing area of the TC255P is configured in 243 lines with 336 elements in each line. Twelve

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 antiblooming is activated

by supplying clocking pulses to the antiblooming gate, which is an integral part of each image-sensing element.

The sensor can be operated in a noninterlace mode as a 324(H) by 243(V) sensor with low dark current. The

device can also be operated in an interlace mode, electronically displacing the image-sensing elements during

the charge integration in alternate fields, and effectively increasing the vertical resolution and minimizing

aliasing.

One important aspect of this image sensor is its high-speed image-transfer capability. This capability allows for

an electronic-shutter function comparable to interline-transfer and frame-interline-transfer sensors without the

loss of sensitivity and resolution inherent in those technologies.

The charge is converted to signal voltage with a 12-

µV per electron conversion factor by a high-performance

charge-detection structure with built-in automatic reset and a voltage-reference generator. The signal is

buffered by a low-noise two-stage source-follower amplifier to provide high output-drive capability.

The TC255P uses TI-proprietary virtual-phase technology, which provides devices with high blue response, low

dark signal, high photoresponse uniformity, and single-phase clocking. The TC255P 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.

DUAL-IN-LINE PACKAGE

(TOP VIEW)

IAG2

ADB

SUB

OUT

ABG

IAG1

SAG

SRG

1

2

3

4

8

7

6

5

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.