Division of Semiconductor REVISION NUMBER: REV B PAGES: Page 1 of 13 DATE: 03/18/05 PI3033B Contact Image Sensor Preliminary Data Sheet Preliminary PI3033B datasheet PI3033B 200DPI CIS Sensor Chip Engineering Data Sheet Description: Peripheral Imaging Corporation PI3033B CIS, Contact Image Sensor, chip is a 200 dot per inch resolution, linear array image sensor chip. The sensor chip is processed with PIC’s proprietary CMOS Image Sensing Technology. Designed for cascading multiple chips in a series, the image sensor chips, using chip-on-board process, are bonded end-to-end on a printed circuit board (PCB) in varying sensing array lengths. Accordingly offering image reading widths to suit document scanners found in facsimile, scanner, check reader, and office automation equipment. Figure 1 is a block diagram of the imaging sensor chip. Each sensor chip consists of 64 detector elements, their associated multiplexing switches, buffers, and a chip selector. The detector's elementto-element spacing is approximately 125 um. The size of each chip without scribe lines is 7950 um by 500 um. Each sensor chip has 8 bonding pads. Only 7 are used to make the CIS Modules. The pad symbols and functions are described in Table 1. 7950 m Row of 64 Sensors and Video Signal Multiplexers 500 Readout Shift Register Buffer SP Chip Select Buffer CP VDD DGND IOUT m Buffer RSTLEV AGND EOS Figure 1. PI3033B Block Diagram SYMBOL SP CP VDD DGND RSTLEV IOUT AGND EOS FUNCTION Start Pulse: Input to start the line scan. Clock Pulse: Input to clock the Shift Register. Positive Supply: +5 volt supply connected to substrate. Digital Ground: Connection topside common A Bias Pad: Not used, left floating Signal Current Output: Output for video signal current Analog Ground: Connection topside common End of Scan Pulse: Output from the shift register at end of scan. Table 1. Pad Symbols and Functions Page 2 of 13 Date: 03/18/05 Preliminary PI3033B datasheet Bonding Pad Outputs Locations and Die Dimensions Figure 2 shows image sensors die dimension and the bonding pad locations for PI3033B Sensor Chip. The location is referenced to the lower left corner of the die. Note RSTLV, bias, pad is not used. Figure 2. Bonding Pad and Chip Layout: Page 3 of 13 Date: 03/18/05 Preliminary PI3033B datasheet Wafer Scribe Lines Bordering The Die Figure 3 shows the wafer scribe lines bordering the PI3033B Sensor Chip. The wafer thickness is 350µcrons. Figure 3. Wafer Scribe Lines Page 4 of 13 Date: 03/18/05 Preliminary PI3033B datasheet Electro-Optical Characteristics (25o C) The electro-optical characteristics of PI3033B imaging sensor chip are listed in Table 2. These values are measured at 25o C. Parameters Number of Photo-elements Pixel-to-pixel spacing Line scanning rate Clock frequency Symbols Output voltage Output voltage non-uniformity Dark output voltage Dark output non-uniformity Adjacent Pixel non-uniformity Chip-to-chip non-uniformity Tint (1) Fclk (2) Typical 64 125 864 2.0 Units elements µm µs/line MHz Vpavg (3) Up (4) Vd (5) Ud (6) Upadj (7) Ucc (8) 1.0 ± 7.5 <20 <10 <7.5 ± 7.5 V % mV mV % % Notes See note 2 for higher clock speed. (maximum 5 MHz) Exp = 1.8 X 10 –2 µJ/cm 2 Note 5 & 3 Note 6 & 3 Table 2. Electro-Optical Characteristic Notes: (1) (2) (3) (4) (5) (6) (7) (8) Tint stands for the line scanning rate or the integration time. It is determined by the time interval between two start pulses. Fclk stands for the input clock frequency. For Fclk > 2.0 MHz see note 3 and the section Video Output Response Under Exposure. Vpavg = ∑Vp(n)/Npixels (average level in one line scan). Where Vp(n) is the amplitude of nth pixel in the sensor chip and Npixels is the total number of pixels in sensor chip. Vpavg is converted from impulse current video pixel into a voltage output. See Figure 4, Video Pixel Output in section Output Circuit Of The Image Sensor and Figure 5, Video Output Test and Application Circuit in section Signal Conversion Circuit on page 6 and 7. Exp = LP x Tint, where LP is light power (Yellow-Green) and Tint is as defined above. See Figure 6, Vpavg Output versus Light Exposure in section Video Output Response Under Exposure, on page 8. Up is the uniformity specification, measured under a uniform exposing light exposure. Up = [Vp(max) - Vpavg] / Vpavg x 100% or [Vpavg - Vp(min)] / Vpavg} x 100%, whichever is greater. Where Vp(max) is the maximum pixel output voltage in the light. Vp(min) is the minimum pixel output voltage in the light. Vd = ∑Vp(n)/Npixels. Where Vp(n) is the pixels signal amplitude of the nth pixel of the sensor. Dark is where the sensor is placed in the dark environment. Ud = Vdmax – Vdmin. Dark is same definition as above. Upadj = MAX[ | (Vp(n) - Vp(n+l) | / Vp(n)) x 100%. Upadj is the nonuniformity in percentage. It is the amplitude difference between two neighboring pixels. Ucc is the uniformity specifications, measured among the good die on the wafer. Under uniform light exposure the sensors are measured and calculated with following algorithm: Vpavg of all the good dies on the wafer are averaged and assigned VGpavg. Then the die with maximum Vpavg is assigned Vpavg(max), Page 5 of 13 Date: 03/18/05 Preliminary PI3033B datasheet and the one with minimum Vpavg is assigned Vpavg(min). Then UCC = {[Vpavg(max)-Vpavg(min)]/VGpavg}x100. Output Circuit Of The Image Sensor The video signal from each photo-site is connected to a common video line on the sensor. Each photo-site is composed of a phototransistor with a series MOS switch connecting its emitter to a common video line. The video line is connected to the pad labeled IOUT. The photo-sensing element is the base of the phototransistor where it detects and converts the light energy to proportional charges and stores them in its base capacitance. When the MOS switch is activated, the emitter is connected to the video line and acts as source follower, producing an impulse current proportional to the stored charges in the base. This current is a discrete-time analog signal output called the video pixel. Accordingly the video pixel is proportional to the light energy impinging in the neighborhood of its photo-sites. Figure 4, Video Pixel Output Structures, show the output structure of four photo-sites out of 64. The multiplexing MOS switch in each photo-site terminates into the output pad, IOUT, through a common video line. The shift register sequentially accesses each photo-site by a activating the MOS switch. As they are accessed, a sequence of video pixels is sent to the IOUT where they are processed with an external signal conversion circuit. Figure 4. Video Pixel Output Structures Page 6 of 13 Date: 03/18/05 Preliminary PI3033B datasheet Signal Conversion Circuit Figure 5. Video Output Test and Application Circuit Figure 5, Video Output Test and Application Circuit shows a simply circuit that provides the cleanest technique in processing the video output. It integrates all the currents from each pixel element onto a capacitor, CAP. Then the CAP is reset to zero volts by activating the shunt switch, SW, and connecting the video line to ground prior to accessing the following pixel element. Simultaneous to SW activation, the pixel element storage is, also, reset to the dark level, hence initialized for the new pixel integration process. Since this process sums the switch edges and signal current pulses onto the CAP, it minimizes the switching patterns on the video pixels. The summed charges stored in the CAP, produces a pixel voltage with amplitude proportional to the charge from the current pulse. Since switching energies are high frequencies components, they tend to integrate to a 0 value and the remainder adds a constant value to the dark level. The signal pixels Vp(n) is referenced to the Dark Level as it is seen in Figure 6, Single Pixel Output Voltage that depicts the typical pixel waveform. Figure 6. Single Pixel Video Output To measure these device’s parameters the value of the CAP is set to 100pf. This value includes the stray capacitance of the video line. The value of RIN in the amplifier circuit is set to infinity, it is removed, accordingly, the amplifier gain is one, hence serving as buffer amplifier, EL2044, AD8051 or equivalent, to isolate the video line. Page 7 of 13 Date: 03/18/05 Preliminary PI3033B datasheet Since the output is specified with a light exposure, the video output is specified with a fixed exposure. However, exposure is a function of power and time, Exp = Light power x the Tint, as well as its color. Accordingly the PI3033B is measured with a Yellow-Green LED light source. See Figure 7.Vpavg As Function Of Exposure. Note: The value of 100pf is selected because the typical PCB layout of an A6 length module has a video line capacitance, including the stray, in the order of 100pf. The A6 length CIS module uses 13 sensor chips. See Figure 9. Typical A6 CIS Module Circuit using the PI3033B sensors. Video Output Response Under Exposure Vpavg Output As A Function Of Exposure 3.000 Vpavg (Volts) 2.500 2.000 1.500 1.000 0.500 0.000 8.00E-02 7.00E-02 6.00E-02 5.00E-02 4.00E-02 3.00E-02 2.00E-02 1.00E-02 0.00E+00 Exposure (MicroJoules/cm^2) Figure 7.Vpavg As A Function Of Exposure Absolute Maximum Ratings: Parameters Power Supply Voltage Power Supply Current Input clock pulse (high level) Input clock pulse (low level) Operating Temperature Symbol VDD IDD Vih Vil Top Maximum Rating 10 <2.0 Vdd + 0.5 -0.25 0 to 50 Page 8 of 13 Date: 03/18/05 Units Volts mA Volts Volts o C Preliminary PI3033B datasheet Operating Humidity Storage Temperature Storage Humidity Hop Tstg Hstg 10 to 85 -25 to 75 10 to 90 RH % o C RH % Table 3. Absolute Maximum Ratings Recommended Operating Conditions at Room Temperature Parameters Power Supply Input clock pulses high level Input clock pulse low level Operating high level exposed output Clock Frequency Clock pulse duty cycle Clock pulse high durations Integration time Operating Temperature Symbol VDD Vih (1) Vil (1) IOUT (2) Fclk (3) Duty (4) tw Tint Top Min. 4.5 3.0 0 0.1 Typical 5.0 5.0 0 See note. 2.0 25 0.125 0.864 25 Max. 5.5 VDD 0.8 Units Volts Volts Volts 5.0 MHz % µsec ms o C 10 50 Table 4. Recommended Operating Condition at Room Temperature Note (1) (2) (3) (4) Applies to both CP and SP. The output is a current that is proportional to the charges, which are integrated on the phototransistor’s base via photon-to-electron conversion. For its conversion to voltage pixels see Figure 4, Video Pixel Output in section Output Circuit Of The Image Sensor. Although the clock frequency, Fclk, will operate the device at less than 100KHz, it is recommended that the device be operated above 500KHz to avoid complication of leakage current build-up. In applications using long CIS module length, such as an array of image sensor > 27, increases the readout time, i.e., increases Tint, hence, leakage current build-up occurs. The clock duty cycle typically is normally set to 25 %. However, it can operate with duty cycle as large as 50 %, which will allow more reset time at the expense of video pixel readout time. Page 9 of 13 Date: 03/18/05 Preliminary PI3033B datasheet Switching Characteristics @ 25o C. The timing relationships of the video output voltage and its two input clocks the start pulse, SP, and the shift register clock, CP, along with the shift register EOS output clock are shown in Figure 8, Timing Diagram Of The PI3033B Sensor. The switch timing specification for the symbols on the timing diagram is given in Table 5, Timing Symbol's Definition below the timing diagram. The digital clocks' levels are +5 Volts CMOS compatible. The video, IOUT, is specified in Figure 4, Video Pixel Output in section Output Circuit Of The Image Sensor. Figure 8. Timing Diagram Of The PI3033B Sensor Item Clock cycle time Clock pulse width(1) Clock duty cycle Data setup time Data hold time Prohibit crossing time(2) EOS rise delay EOS fall delay Signal delay time(3) Signal settling time(3) Symbol to tw tds tdh tprh terdl tefdl tdl ts/h Minimum 200 50 25 20 20 Mean Maximum 10000 50 75 20 60 70 20 120 Units ns ns % ns ns ns ns ns ns ns Table 5. Timing Symbol's Definition Notes (1) Since, the clock pulse width varies with frequency, tw will vary according to duty cycle. Page 10 of 13 Date: 03/18/05 Preliminary PI3033B datasheet (2) (3) Prohibit crossing time is to insure that no two start pulses are locked into the shift register for any single scan time. Since the start pulse is entered into the shift register during its active high level when the CP clock edges falls, the active high of the start pulse is permitted only during one falling, CP, clock edges for any given scan. Otherwise, multiple start pulses will load into the shift register. Pixel delay times and settling time depend on the output amplifier, which is employed. These values, tdl and ts/h, are measured with the amplifier see in Figure 9. Typical A6 CIS Module Circuit using the PI3033B sensors. Note, the impulse signal current out of the device has pulse width ~ 30 ns. Hence, the faster the amplifier with a faster settling time will yield a signal video pulse with faster rise and settle times. Typical A6 CIS Module Circuit See Figure 9. Typical A6 CIS Module Circuit using the PI3033B sensors. The circuit is provided as reference to illustrate the interconnection of the PI3033B for a serially cascaded line of image sensors. It is a typical A6 size CIS module produced by PIC. It provides the first time user with additional insight for designing a CIS module and supplements the circuit descriptions given in the section, Signal Output Conversion, page 5. The difference is in the arrangement of the two shunt switches, U2D, and U2A. U2D is a counterpart to SW in Figure 5. Video Output Test and Application Circuit. A DC restoration capacitor, C20, with value of 100pf added between the shunts switch. The first, U2D, clamps the video line to ground to reset the image sensors. Simultaneously the second, U2A, clamps the node between C20 and amplifier input to a output reference bias voltage that is on the node between R4 and R9. These resistors are voltage divider that sets the DC operating level of the amplifier’s output by applying same bias voltage to both inputs of the amplifier (See next page for the Typical A6 CIS Module Circuit.) Page 11 of 13 Date: 03/18/05 Preliminary PI3033B datasheet Figure 9. Typical A6 CIS Module Circuit Page 12 of 13 Date: 03/18/05 Preliminary PI3033B datasheet ______________________________________________________________________________ © 2005 Peripheral Imaging Corporation. Printed in USA. All rights reserved. Specifications are subject to change without notice. Contents may not be reproduced in whole or in part without the express prior written permission of Peripheral Imaging Corporation. Information furnished herein is believed to be accurate and reliable. However, no responsibility is assumed by Peripheral Imaging Corporation for its use nor for any infringement of patents or other rights granted by implication or otherwise under any patent or patent rights of Peripheral Imaging Corporation. Page 13 of 13 Date: 03/18/05