TC271

1080

× 580-PIXEL CCD IMAGE SENSOR

SOCS039A – JANUARY 1994 – REVISED JUNE 1996

Copyright

1

POST OFFICE BOX 655303

Image Sensor for Video or Still-Picture

Photography

Allows Multimode Operation

Image-Sensing Area

With 2/3” Vidicon Optics

Off-Chip Implementation of CCSH Video-

Signal Processing

Burn-in, Residual Imaging, Image

Distortion, Image Lag, or Microphonics

description

The TC271 is a frame-transfer charge-coupled-device (CCD) image sensor with two field memories. It is

suitable for use in PAL-video or still-picture photography applications. Its image-sensing area is configured into

580 lines; 576 of these are active and the remaining four are used for dark reference. Each line is configured

into 1080 pixels with 1044 active and 36 for dark reference. The TC271 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 TC271 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 CCIR with true interlace, CCIR with pseudointerlace, progressive scan, and

nonstandard pseudointerlace with a resolution of 1152 lines.

A unique multiplexer section (see Figure 1) 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 2 and the functional block diagram). Each register and associated amplifier reads out every third column

of the image area (see Figure 3). 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 TC271 is built using TI-proprietary virtual-phase technology, which provides devices with high blue

response, low dark current, high photoresponse uniformity, and single-phase clocking. The TC271 is

characterized for operation from –10

°C to 40°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.

SUB

CDB

AMP GND

OUT1

OUT2

OUT3

ADB

SAG1

IAG

ABG

SUB

SUB

TRG

SRG1

SRG2

SRG3

SAG2

TMG

IAG

ABG

TDB

SUB

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

DUAL-IN-LINE PACKAGE

(TOP VIEW)

ADVANCE INFORMATION concerns new products in the sampling or

preproduction phase of development. Characteristic data and other

specifications are subject to change without notice.