TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 • • • • • • • • • • • • • • • Medium-Resolution, Solid-State Image Sensor for Low-Cost Color TV Applications 324(H) x 243(V) Active Elements in Image Sensing Area 10-µm Square Pixels Small Size Low Cost Fast Clear Capability Electronic Shutter Function From 1/60–1/50000 s Low Dark Current Electron-Hole Recombination Antiblooming Dynamic Range . . . 66 dB Typical High Sensitivity High Blue Response 8-Pin Dual-In-Line Plastic Package 4-mm Image-Area Diagonal Solid-State Reliability With No Image Burn-In, Residual Imaging, Image Distortion, Image Lag, or Microphonics DUAL-IN-LINE PACKAGE (TOP VIEW) IAG2 1 8 ABG ADB 2 7 IAG1 SUB 3 6 SAG OUT 4 5 SRG description The TC254P is a frame-transfer charge-coupled device (CCD) designed for use in color NTSC TV and specialpurpose applications requiring low cost and small size. The image-sensing area of the TC254P 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 non-interlace mode as a 324(H) by 243(V) square color pixel mode by alternately averaging two red pixels for red pixels and two blue pixels for blue pixels. Because the human eye is most sensitive to the green light wavelength, the 324× 243 resolution is preserved due to the orientation of the green pixels in the Bayer mosaic color filter pattern. The device can also be operated in a 162(H) by 121(V) square color pixel mode by utilizing a separate red, two averaged greens, and a blue pixel for each color pixel. In this mode, true interlaced video is possible, effectively increasing the vertical resolution, by performing a one pixel shift during the off-chip video processing. 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. 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. Copyright 1998, Texas Instruments Incorporated 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. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 description (continued) 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 TC254P 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 TC254P is characterized for operation from –10°C to 45°C. functional block diagram Image Area With Blooming Protection IAG2 ADB 1 Dark Reference Elements IAG1 Clear Line OUT 3 6 Storage Area Amplifier 4 SAG Serial Register ÉÉÉÉÉÉÉÉÉÉ ÉÉÉÉÉÉÉÉÉÉ Clearing Drain 2 7 ABG 2 2 Dummy Elements SUB 8 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 SRG TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 sensor topology diagram Pixel 1 2 3 4 5 6 R G R G R G 323 324 R G B G B G B R G R G R G G B G B G B G Line 243 G B Line 242 R G Line 241 G B Line 240 Buffer Column 243 Lines 12 OB R G R G R G R G Line 4 G B G B G B G B Line 3 R G R G R G R G Line 2 G B G B G B G B Line 1 1 Dark Line 1Clear Line 244 Lines Storage Area 336 Pixels OB = Optical Black R = Red B = Blue G = Green 1 2 3 4 5 6 12 OB 323 324 R G SRG Terminal Functions TERMINAL I/O DESCRIPTION NAME NO. ABG 8 I Antiblooming gate ADB 2 I Supply voltage for amplifier-drain bias SUB 3 IAG1 7 I Image-area gate 1 IAG2 1 I Image-area gate 2 OUT 4 O Output SAG 6 I Storage-area gate SRG 5 I Serial-register gate Substrate POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 detailed description The TC254P consists of five basic functional blocks: (1) the image-sensing area, (2) the image-clear line, (3) the storage area, (4) the serial register, and (5) the charge-detection node and output amplifier. image-sensing area Cross sections with potential well diagrams and top views of image-sensing and storage-area elements are shown in Figure 1 and Figure 2. As light enters the silicon in the image-sensing area, free electrons are generated and collected in the potential wells of the sensing elements. During this time, the antiblooming gate is activated by the application of a burst of pulses every horizontal blanking interval. This prevents blooming caused by the spilling of charge from overexposed elements into neighboring elements. Twelve columns of shielded-from-light elements on the left edge of the image-sensing area generate the dark reference necessary in subsequent video processing circuits for restoration of the video-black level. There is also one column of elements on the right side of the image-sensing area and one line between the image-sensing area and the image-clearing line. 10 µm Light Clocked Barrier IAG 10 µm Virtual Barrier Antiblooming Gate ABG Antiblooming Clocking Levels Virtual Well Clocked Well Accumulated Charge Figure 1. Charge-Accumulation Process SAG Clocked Phase Virtual Phase Channel Stops Figure 2. Charge-Transfer Process image-clear line During start-up or electronic-shutter operations, it is necessary to clear the image area of charge without transferring it to the storage area. In such situations, the two-image area gates are clocked 244 times without clocking the storage-area gate. The charge in the image area is then cleared through the image-clear line. 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 storage area After exposure, the charge captured in each image-area is transferred through the image clear line to the storage area. The stored charge is then transferred line by line into the serial register for readout. Figure 3 illustrates the timing to (1) transfer the image to the storage area, and (2) to transfer each line from the storage area to the serial register. serial register Each line, after it is clocked into the serial register, is read out pixel by pixel. Figure 3 illustrates the serial-register clock sequence. 244 Cycles Composite Blank Integration Time ABG Electronic Shutter Operation 244 Clocks 244 Clocks IAG1 IAG2 SAG 339 Cycles SRG t = 80 ns SAG 1) 2) 3) IAG1 SRG IAG2 1) End of serial readout of line 2) Transfer of new line to serial register 3) Beginning of readout of new line SAG SRG Expanded Section of Parallel Transfer Figure 3. Timing Diagram POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 charge-detection node and output amplifier The buffer amplifier converts the charge into a video signal. Figure 4 shows the circuit diagram of the charge-detection node and output amplifier. As charge is transferred into the detection node, the potential of this node changes in proportion to the amount of signal received. This change is sensed by a MOS transistor and, after proper buffering, the signal is supplied to the output terminal of the image sensor. After the potential change is sensed, the node is reset to a reference voltage supplied by an on-chip reference generator. The reset is accomplished by a reset gate that is connected internally to the serial register. The detection node and buffer amplifier are located a short distance away from the edge of the storage area; therefore, two dummy cells are used to span this distance. Reference Generator Q0 ADB Q2 Q1 Q3 QR Q5 SRG Detection Node VO Q4 Figure 4. Buffer Amplifier and Charge-Detection Node 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 Q6 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 spurious-nonuniformity specification The spurious-nonuniformity specification of the TC254P is based on several sensor characteristics: • • • Amplitude of the nonuniform pixel Polarity of the nonuniform pixel – Black – White Column amplitude The CCD sensor is characterized in both an illuminated condition and a dark condition. In the dark condition, the nonuniformity is specified in terms of absolute amplitude, as shown in Figure 5. In the illuminated condition, the nonuniformity is specified as a percentage of the total illumination, as shown in Figure 6. The specification for the TC254P is as follows: WHITE SPOT (DARK) WHITE SPOT (ILLUMINATED) COLUMN (DARK) COLUMN (ILLUMINATED) BLACK SPOT (ILLUMINATED) x < 15 mV x < 15% x < 0.5 mV x < 1 mV x < 15% † A white/black pair nonuniformity will be no more than 2 pixels even for integration times of 1/60 second. WHITE/BLACK† PAIR x < 9mV The conditions under which this specification is defined are as follows: • • • The integration time is 1/60 second except for illuminated white spots, illuminated black spots, and white/black pair nonuniformities; in these three cases, the integration time is 1/120 second. The temperature is 45°C. The CCD video-output signal is 60 mV ± 10 mV. % mV Amplitude % of Total Illumination t Figure 5. Pixel Nonuniformity, Dark Condition POST OFFICE BOX 655303 t Figure 6. Pixel Nonuniformity, Illuminated Condition • DALLAS, TEXAS 75265 7 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 absolute maximum ratings over operating free-air temperature (unless otherwise noted)† Supply voltage range, VCC: ADB (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to 15 V Input voltage range, VI: ABG, IAG1, IAG2, SAG, SRG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 15 V to 15 V Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 10°C to 45°C Storage temperature range, TSTG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 30°C to 85°C † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTE 1: All voltages are with respect to the substrate terminal. recommended operating conditions Supply voltage, VCC ADB MIN NOM MAX 11 12 13 Substrate bias voltage 0 IAG1 IAG2 IAG1, SAG Input voltage, VI SRG ABG 1.5 2 2.5 Low level –10.5 –10 –9.5 High level 1.5 2 2.5 Low level –10.5 –10 –9.5 High level 1.5 2 2.5 Low level –10.5 –10 –9.5 High level 3.5 4 4.5 Low level –6 12.5 25 SAG 12.5 6.25 OUT 0.008 Operating free-air temperature, TA ‡ Adjustment is required for optimum performance. POST OFFICE BOX 655303 –10 • DALLAS, TEXAS 75265 MHz 12.5 6 Plastic package thermal conductivity 8 –7 6.25 IAG1, IAG2 SRG Load capacitance V –2.5 –8 ABG Clock frequency, frequency fclock l k V V High level Intermediate level‡ UNIT pF J/cm•s•°C 45 °C TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 electrical characteristics over recommended operating ranges of supply voltage and free-air temperature (unless otherwise noted) PARAMETER Dynamic range (see Note 2) MIN Antiblooming disabled (see Note 3) Charge-conversion factor TYP MAX UNIT 12 13 µV/e 0.9999 1 66 11 Charge-transfer efficiency (see Note 4) Signal-response delay time, τ (see Note 5) dB 20 Gamma (see Note 6) 0.97 0.98 ns 0.99 350 Ω Noise-equivalent signal without correlated double sampling 62 electrons Noise-equivalent signal with correlated double sampling (see Note 7) 31 electrons Output resistance ADB (see Note 8) Rejection ratio 13 15 SRG (see Note 9) 50 ABG (see Note 10) 40 Supply current 5 IAG1, IAG2 Input capacitance, capacitance Ci 18 dB 10 mA 1000 SRG 22 ABG 850 SAG 2000 pF NOTES: 2. Dynamic range is – 20 times the logarithm of the mean-noise signal divided by saturation-output signal. 3. For this test, the antiblooming gate must be biased at the intermediate level. 4. Charge-transfer efficiency is one minus the charge loss per transfer in the output register. The test is performed in the dark using an electrical-input signal. 5. Signal-response delay time is the time between the falling edge of the SRG pulse and the output-signal valid state. 6. Gamma (γ) is the value of the exponent in the equation below for two points on the linear portion of the transfer-function curve (this value represents points near saturation). ǒ Ǔ +ǒ Exposure (2) Exposure (1) g Ǔ Output signal (2) Output signal (1) 7. A three-level serial-gate clock is necessary to implement correlated double sampling. 8. ADB rejection ratio is – 20 times the logarithm of the ac amplitude at the output divided by the ac amplitude at ADB. See Figure 7 for measured ADB rejection ratio as a function of frequency. 9. SRG rejection ratio is – 20 times the logarithm of the ac amplitude at the output divided by the ac amplitude at SRG. 10. ABG rejection ratio is – 20 times the logarithm of the ac amplitude at the output divided by the ac amplitude at ABG. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 optical characteristics, TA = 40°C (unless otherwise noted) PARAMETER Sensitivity† MIN TYP Red with CM500 IR filter 9.5 Green with CM500 IR filter 10 Blue with CM500 IR filter MAX UNIT mV/lux 7 Saturation signal, Vsat (see Note 11) Antiblooming disabled, Interlace off 600 750 mV Maximum usable signal, Vuse Antiblooming enabled 200 250 mV 100 200 Blooming-overload ratio (see Note 12) Image-area well capacity 43000 Smear (see Notes 13 and 14) Dark current 62500 electrons 0.00012 Interlace disabled, TA = 21°C nA/cm2 0.20 200 µV Pixel uniformity Output signal = 60 mV ± 10 mV 15 mV Column uniformity Output signal = 60 mV ± 10 mV 0.5 mV 15 % Dark signal Shading Electronic-shutter capability 1/15000 1/60 s † Standard illuminates 2856K NOTES: 11. Saturation is the condition in which further increase in exposure does not lead to further increase in output signal. 12. Blooming is the condition in which charge is induced in an element by light incident on another element. Blooming-overload ratio is the ratio of blooming exposure to saturation exposure. 13. Smear is a measure of the error introduced by transferring charge through an illuminated pixel in shutterless operation. It is equivalent to the ratio of the single-pixel transfer time to the exposure time using an illuminated section that is 1/10 of the image area vertical height with recommended clock frequencies. 14. The exposure time is 16.67 ms, the fast-dump clocking rate during vertical transfer is 12.5 MHz, and the illuminated section is 1/10 of the height of the image section. timing requirements tr tf 10 Rise time Fall time MIN NOM ABG 10 40 IAG1, IAG2 (fast clear) 10 10 IAG1, IAG2 (image transfer) 10 20 SAG 10 20 SRG 10 40 ABG 10 40 IAG1, IAG2 (fast clear) 10 10 IAG1, IAG2 (image transfer) 10 20 SAG 10 20 SRG 10 40 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 MAX UNIT ns ns TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 PARAMETER MEASUREMENT INFORMATION Blooming Point With Antiblooming Enabled VO Blooming Point With Antiblooming Disabled Dependent on Well Capacity Vsat (min) Level Dependent Upon Antiblooming Gate High Level Vuse (max) DR Vuse (typ) SNR Vn DR (dynamic range) + 20 log SNR (signal-to-noise-rate) ǒ Ǔē V sat Vn + 20 log ǒ Lux (light input) B V use Vn Ǔē B Vn = noise-floor voltage Vsat (min) = minimum saturation voltage Vuse (max) = maximum usable voltage Vuse (typ) = typical user voltage (camera white clip) NOTES: A. Vuse (typ) is defined as the voltage determined to equal the camera white clip. This voltage must be less than Vuse (max). B. A system trade-off is necessary to determine the system light sensitivity versus the signal/noise ratio. By lowering the Vuse (typ), the light sensitivity of the camera is increased; however, this sacrifices the signal/noise ratio of the camera. Figure 7. Typical Vsat, Vuse Relationship POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 PARAMETER MEASUREMENT INFORMATION 1.5 V to 2.5 V SRG – 8.5 V – 8.5 V to – 10 V 0% OUT 90% 100% CCD Delay t 10 ns 15 ns Sample and Hold Figure 8. SRG and CCD Output Waveforms 12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 TYPICAL CHARACTERISTICS TC254 SPECTRAL RESPONSE WITH CM500 TOPPAN DYE COLOR FILTER 12 11 Responsivity – V/W/m ∧ 2 10 9 8 7 6 Green 5 4 Blue Red 3 2 1 0 300 340 380 420 460 500 540 580 620 660 700 740 Wavelength – nm POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 APPLICATION INFORMATION TMC57253 VCC VAB VCC WIN TEST1 GND TEST3 TEST2 MON1 MON3 MON4 EFSEL2 EFSEL1 EFSEL3 VCC MINSEL WSEL1 WSEL2 MON2 IAG2 TMC57750 SSEL1 SAG VCC SSEL2 GND SRG SRM SSEL3 DLSEL VR HR PHSEL2 PHSEL1 SRGSEL VACT 64 63 62 61 60 59 VCC 58 57 VAB VCC GND EN VABM ABOUT VABL GND ABIN IA1OUT 24 23 22 21 20 19 18 17 16 15 14 13 VIA ABMIN IA1IN IA2OUT IA2IN GND SAIN SRIN SAOUT VS SRMIN SROUT VSM GND VABM VABL VIA VS VSM 56 55 54 53 52 TC254P 8 ABG IAG2 7 ADB IAG1 6 SUB SAG 5 SRG OUT 51 50 49 1 2 ADB 3 SUB 4 FI SHTCOM VD 32 CPOB2 HD 30 31 IAG1 PUC VCC 28 29 CPOB1 SCAN 27 GND ABM VCC CLKIN VCC 25 26 ABG CBLK CSYNC XIN 24 ABGSEL TEST4 MCLK/2 XSEL XOUT CPOB1 22 23 FSSEL MCLK/4 CSYNC 20 21 DSSEL EU CDS GND 19 CBLK ED S/H 17 18 SHTMON ED EU WINDOW 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 9 10 11 12 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Buffer and Preamp VCC S/H CDS (see Note B) VCC VCC 5V GND OUT To Video Processing 25 MHz DC VOLTAGES VIA, VSM, VS 12 V VCC 5V ADB 22 V SUB 10 V VABM 7.5 V VAB VABL 14 V 3V Figure 9. Typical Application Circuit Diagram NOTES: A. Decoupling capacitors are not shown. B. TI recommends designing AC coupled systems. 14 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TC254P 336- × 244-PIXEL CCD IMAGE SENSOR SOCS060B – JUNE 1997 – REVISED JULY 1998 MECHANICAL DATA The package for the TC254P consists of a plastic base, a glass window, and an 8-lead frame. The glass window is sealed to the package by an epoxy adhesive. The package leads are configured in a dual in-line organization and fit into mounting holes with 2,54 mm (0.1 in) center-to-center spacings. Package Center 10,05 9,95 9,00 8,90 0,80 0,70 Optical Center 10,05 9,95 Package Center 5,19 4,93 ÎÎÎ ÎÎ ÎÎÎ ÎÎ ÎÎÎ ÎÎÎ ÎÎÎ 2,67 2,53 10,16 9,00 8,90 4,20 3,93 0,27 0,23 Chip Surface 0,64 0,50 1,10 1,20 3,50 1,27 1,50 1,40 ÎÎ ÎÎÎÎÎ ÎÎ ÎÎÎÎÎ 0,46 2,54 0,30 6/96 ALL LINEAR DIMENSIONS ARE IN MILLIMETERS POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 15 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI’s publication of information regarding any third party’s products or services does not constitute TI’s approval, warranty or endorsement thereof. Copyright 1998, Texas Instruments Incorporated