OPB780-Kit Color Sensor Evaluation Kit • The OPB780-Kit is designed to provide the design engineer an easy way to evaluate the capability of the OPB780 Color Sensor. The OPB780Z is a full color sensor with 4 different frequencies relating directly to a specific color seen by the sensor. Block Current-to-Frequency Out Converter The OPB780Z color sensor uses a Photodiode Array Light programmable light-to-frequency S2 S3 converter that combines 64 configurable silicon photodiodes (on a 144 um center array and measuring 120 um x 120 um 6 4 each) and a current-to-frequency converter on a single monolithic CMOS integrated circuit, packaged in a small, lightweight package that makes it ideal for using in miniature applications. The output is a square wave (50% duty cycle) with a frequency directly proportional to light chromaticity and irradiance from four filtered diode arrays. The light-to-frequency converter reads an 8 x 8 array of photodiodes that consists of four groups of 16 photodiodes each, segregated by color: 16 photodiodes with red filters, 16 photodiodes with green filters, 16 photodiodes with blue filters and 16 photodiodes with clear filters. Each color’s group of 16 photodiodes is interdigitated to minimize the effect of non-uniformity of incident irradiance. Each color’s group is also connected in parallel. The type of photodiode used during operation is pin-selectable. The internal photodiode used by the device is controlled by two logic inputs, S2 and S3. Pin 4 (S2) Pin 6 (S3) Diode Filter H H Green H L Clear L L Red L H Blue 7,8 SO S3 S1 S2 4 OE Out 3 Gnd VDD 1,2 3 6 Cap (0.1µf) 5 LED Pin Name Pin # Description VDD 1, 2 Supply voltage OUT 3 Output Frequency (FO) S2 4 Photodiode type selection input LED Anode 5 LED input S3 6 Photodiode type selection input GND/OE 7, 8 Sensor & LED Ground DO NOT LOOK DIRECTLY AT LED WITH UNSHIELDED EYES OR DAMAGE TO RETINA MAY OCCUR. The OPB780Z includes 10” [25.4cm] a Flat Flexible interface Cable. Custom lengths of the cable can be ordered either from OPTEK or most Flat Flexible Cable (FFC) manufactures. The FFC is designed to interface with an any standard 0.5mm spacing FFC connector similar to the AVX ELCO connector. (part number 04 6249 0080 00 800+). The output of the device is designed to drive a standard TTL or CMOS logic input over short distances. OPTEK reserves the right to make changes at any time in order to improve design and to supply the best product possible. OPTEK Technology Inc. — 1645 Wallace Drive, Carrollton, Texas 75006 Phone: (972) 323-2200 or (800) 341-4747 FAX: (972) 323-2396 [email protected] www.optekinc.com Issue A.2 11/09 Page 1 of 9 OPB780-Kit Color Sensor Evaluation Kit All 16 photodiodes that have the same color filter are connected in parallel. Package pin numbers 4 (S2) and 6 (S3) can be used to select the desired photodiode/filter configuration to optimize color identification. All 64 photodiodes are 120µm x 120µm in size and are on 144µm centers. The output frequency provided by the OPB780Z may vary from part to part and should be calibrated as required to meet each application. The more colors that are to be identified require more accurate calibration and longer sampling rate. A small amount of jitter will be present in the frequency provided for a color and must be taken into consideration depending on the accuracy required. The OPB780Z photodiodes as provided are designed to recognize ultraviolet, visible as well as near infrared wavelengths (from 300 to 1,050 nanometers) The graphs below show the typical Spectral Response for each photodiode configuration. When a near infrared rejecting filter similar to the Hoya CM500 is placed in front of the sensor, the higher wavelengths (above 700 nm) are eliminated thus enhancing recognition of colors in the visible range. Typical Spectral Response Full Wavelength Sensitivity 1.0 Relative Responsivity The OPB780Z consist of: 1. White LED for illumination of the target 2. Photodiode Array consisting of: 16 Green Filter Diodes 16 Clear Filter Diodes 16 Red Filter Diodes 16 Blue Filter Diodes 3. Current to Frequency Converter 4. TTL and CMOS Drive Circuitry 5. Plastic Package with 10: (25.4cm) FFC No rmalized to Clear @ 680 nm 0.9 0.8 0.7 TA = 25° C 0.6 0.5 0.4 0.3 0.2 0.1 0.0 300 500 700 900 1100 λp Wavelength (nm) Frequency-A Frequency-B The internal scaling is preconfigured for the highest frequency output of typically 600kHz. The 600kHz frequency shortens the sampling time providing a small amount of jitter in the output frequency. The user must take into consideration the luminance intensity (amount of light) that may be acknowledged by the human eye. As the luminance intensity decreases, the amount of color recognized is diminished. In order to consistently reproduce a specific color with the same output frequency, the luminance intensity must be the consistent. When critical identification of specific colors is required, the angle of view and distance may critical characteristics. Relative Responsivity Spectral Response 1.0 0.9 No rmalized to Clear @ 530 nm 0.8 0.7 TA = 25° C 0.6 0.5 0.4 0.3 0.2 0.1 0.0 300 500 700 900 1100 λp Wavelength (nm) The standard product allows the OPB780Z to be used to recognize colors over the full wavelength of 300nm to 1100nm beyond those of the human visual range. OPTEK reserves the right to make changes at any time in order to improve design and to supply the best product possible. Issue A.2 11/09 Page 2 of 9 OPTEK Technology Inc. — 1645 Wallace Drive, Carrollton, Texas 75006 Phone: (972) 323-2200 or (800) 341-4747 FAX: (972) 323-2396 [email protected] www.optekinc.com OPB780-Kit Color Sensor Evaluation Kit Below are the operating characteristics of the OPB780Z. As the ambient temperature or other environmental conditions change, the values noted may vary. The OPB780Z is designed to operate between –40°C and +85°C. The OPB780Z provides consistent recognition of a color given constant environmental conditions. Operating Characteristics at VDD = 5 V, TA = 25°C Clear Diode Parameter Test Conditions Output Frequency (fO) Dark Frequency Irradiance Responsivity (Re) (See Note 1) Saturation Irradiance (See Note 2) Illuminance Responsivity (RV) (See Note 3) Nonlinearity (See Note 4) Blue Diode Green Diode Red Diode S2 = H, S3 = L S2 = L, S3 = H S2 = H, S3 = H S2 = L, S3 = L Units Min Typ Max Min Typ Max Min Typ Max Min Typ Max Ee = 47.2 µW/cm2 λP = 470 nm 16.0 20.0 24.0 11.2 16.4 21.6 - - - - - - kHz Ee = 40.4 µW/cm2 λP = 524 nm 16.0 20.0 24.0 - - - 8.0 13.6 19.2 - - - kHz Ee = 34.6 µW/cm2 λP = 640 16.0 20.0 24.0 - - - - - - 14.0 19.0 24.0 kHz Ee = 0 - 2 12 - 2 12 - 2 12 - 2 12 Hz λP = 470 nm - 424 - - 348 - - 81 - - 26 - λP = 524 nm - 495 - - 163 - - 337 - - 35 - λP = 565 nm - 532 - - 37 - - 309 - - 91 - λP = 640 nm - 578 - - 17 - - 29 - - 550 - λP = 470 nm - 1410 - - 1720 - - - - - - - λP = 524 nm - 1210 - - - - - 1780 - - - - λP = 565 nm - 1130 - - - - - 1940 - - - - λP = 640 nm - 1040 - - - - - - - - 1090 - λP = 470 nm - 565 - - 464 - - 108 - - 35 - λP = 524 nm - 95 - - 31 - - 65 - - 7 - λP = 565 nm - 89 - - 6 - - 52 - - 15 - λP = 640 nm - 373 - - 11 - - 19 - - 355 - (fO) = 0 to 5 kHz - ±0.1 - - ±0.1 - - ±0.1 - - ±0.1 - (fO) = 0 to 50 kHz - ±0.2 - - ±0.2 - - ±0.2 - - ±0.2 - (fO) = 0 to 500 kHz - ±0.5 - - ±0.5 - - ±0.5 - - ±0.5 - Hz / ( µW/cm2) ( µW/cm2) Hz / Lux % Full Scale Notes: 1. Irradiance Responsivity (Re) is measured over the range from Frequency 0 to 5 kHz. 2. Saturation Irradiance—(Full-Scale Frequency) / (Irradiance Responsivity) 3. Illuminance Responsivity is calculated from the Irradiance Responsivity using the appropriate wavelength LED. 4. Nonlinearity is defined as the deviation of the Output Frequency utilizing a straight line between 0 and full scale and is expressed as a percent of full scale. OPTEK reserves the right to make changes at any time in order to improve design and to supply the best product possible. OPTEK Technology Inc. — 1645 Wallace Drive, Carrollton, Texas 75006 Phone: (972) 323-2200 or (800) 341-4747 FAX: (972) 323-2396 [email protected] www.optekinc.com Issue A.2 11/09 Page 3 of 9 OPB780-Kit Color Sensor Evaluation Kit One of the critical parts of the OPB780Z is the LED. It is very important to understand its characteristics relative to forward current and temperature. The below chart shows how the forward current of the LED changes the Chromatic coordinates. 0.35 IFP = 20 mA 0.34 0° C 0.32 0.35 25° C 50° C 0.31 Forward Current vs Chromaticity Coordinate -30° C 0.33 Y As can be seen, increasing the forward current of the LED lowers the “Y” value while minimally changing the “X” value. The projected most optimum light (equivalent to sun light at 12 noon with no contaminates in the air) has both “X” and “Y” chromatic values of 1/3. Chromatic numbers below 1/3 consist of more Blue or Green wavelengths and numbers above 1/3 consist of more Red or Yellow wavelengths. As can be seen a forward current of approximately 4 mA would provide the most optimum “Y” value. Ambient Temperature vs Chromaticity Coordinate 0.30 0.29 85° C 0.30 0.31 0.32 0.33 0.34 X TA = 25° C 0.34 The graphs show the change in chromaticity vs temperature. As the temperature reduces the “X” value moves closer toward the optimum (1/3) value. In conclusion, the lower the forward current and the cooler the temperature, the closer the LED transmits to the optimum chromatic values of “X”=1/3 and “Y”=1/3. 1 mA 0.33 Y 5 mA 0.32 20 mA 50 mA 0.31 0.30 0.29 100 mA 0.30 0.31 0.32 X 0.33 0.34 In order to provide sufficient light levels and the best color resolution, the white LED should be driven with at least 20 mA of forward current and operated at room temperatures (approx. 25°C). These conditions result in chromatic ranges of about “X”=0.31 and “Y”=0.32. The responsivity of the each diode group is dependent on the angular position of the device to the object. The graphs showing the typical variance of the Output frequency of the device vs both Azmuth (twist) and Zenith (bend) are shown in the two graphs. OPTEK reserves the right to make changes at any time in order to improve design and to supply the best product possible. Issue A.2 11/09 Page 4 of 9 OPTEK Technology Inc. — 1645 Wallace Drive, Carrollton, Texas 75006 Phone: (972) 323-2200 or (800) 341-4747 FAX: (972) 323-2396 [email protected] www.optekinc.com OPB780-Kit Color Sensor Evaluation Kit OPB780 White Surface 8,600 28,500 28,000 Red Diodes Green Diodes Blue Diodes 8,200 27,500 8,000 27,000 7,800 26,500 Clear Diodes Clear Diode Output (Hz) Red, Green, Blue Diode Output (Hz) 8,400 θ 7,600 26,000 7,400 7,200 25,500 -5 -4 -3 -2 -1 0 1 2 3 4 5 Zenith (°) OPB780 White Surface 26,800 8,100 26,600 Red Diodes Green Diodes 26,400 7,900 Blue Diodes 26,200 7,800 26,000 7,700 25,800 7,600 Clear Diode Output (Hz) Red, Green, Blue Diode Output (Hz) 8,000 25,600 7,500 Clear Diodes Top View T θ 25,400 7,400 25,200 -5 -4 -3 -2 -1 0 1 2 3 4 5 Azmuth (°) OPTEK reserves the right to make changes at any time in order to improve design and to supply the best product possible. OPTEK Technology Inc. — 1645 Wallace Drive, Carrollton, Texas 75006 Phone: (972) 323-2200 or (800) 341-4747 FAX: (972) 323-2396 [email protected] www.optekinc.com Issue A.2 11/09 Page 5 of 9 OPB780-Kit Color Sensor Evaluation Kit The distance of the object from the sensor is a critical parameter with typical frequency responses for each Diode and filter combination graphed below. Red Diode Filters Output Frequency vs Distance Clear Diode Filter Output Frequency vs Distance 160 45 140 40 Average Average-StdDev Average+StdDev Average Average-StdDev Average+StdDev 35 Output Frequency (kHz) Output Frequency (kHz) 120 100 80 60 40 30 25 20 15 10 20 5 0 0 0 0.1 0.2 0.3 0.4 0.5 0 0.1 0.2 0.4 0.5 Green Diode Filter Output Frequency vs Distance Blue Diode Filters Output Frequency vs Distance 45 50 45 40 Average Average-STd Dev Average+Std Dev 40 Average Average-Std Dev Average+Std Dev 35 Output Frequency (kHz) 35 Output Frequency (kHz) 0.3 Distance (inch) Distance (inch) 30 25 20 30 25 20 15 15 10 10 5 5 0 0 0 0.1 0.2 0.3 0.4 Distance (inch) 0.5 0 0.1 0.2 0.3 0.4 0.5 Distance (inch) OPTEK reserves the right to make changes at any time in order to improve design and to supply the best product possible. Issue A.2 11/09 Page 6 of 9 OPTEK Technology Inc. — 1645 Wallace Drive, Carrollton, Texas 75006 Phone: (972) 323-2200 or (800) 341-4747 FAX: (972) 323-2396 [email protected] www.optekinc.com OPB780-Kit Color Sensor Evaluation Kit OPB780 Color Sensor. (D=0.1 inches from lens tip, White Target) 30 90 85 Red Diodes Green Diodes Blue Diodes Clear Diodes 26 24 80 75 22 20 70 18 65 16 Clear Output Frequency (kHz) Red, Green, Blue Output Frequency (kHz) 28 60 14 55 12 10 50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Temperature (°C) Ambient Temperature vs Forward Voltage LED Relative Luminosity vs Ambient Temperature 1.10 5.4 5.0 1.05 IF = 60 mA 1.00 Forward Voltage VF (V) Relative Luminosity (a.u.) IF = 20 mA IF = 5 mA 4.6 0.95 0.90 4.2 3.8 3.4 0.85 3.0 2.6 0.80 -40 -20 0 20 40 60 Ambient Temperature TA (°C) 80 100 -40 -20 0 20 40 60 80 100 o Ambient Temperature TA ( C) OPTEK reserves the right to make changes at any time in order to improve design and to supply the best product possible. OPTEK Technology Inc. — 1645 Wallace Drive, Carrollton, Texas 75006 Phone: (972) 323-2200 or (800) 341-4747 FAX: (972) 323-2396 [email protected] www.optekinc.com Issue A.2 11/09 Page 7 of 9 OPB780-Kit Color Sensor Evaluation Kit LED Relative Luminous Intinsity vs Forward Current Forward Voltage vs LED Forward Current 30 140 25 100 Forward Current IFP (mA) Relative Luminous Intensity 120 20 80 o TA = 25 C 15 60 10 40 5 20 0 0 0 5 10 15 20 25 Forward Current IF (mA) 30 2.4 35 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 Forward Voltage VF (V) Spectrum LED Allowable Forward Current vs Ambient Temperature 1.2 40 Allowable Forward Current IF (mA) Relative Emission Intensity (a.u.) 1.0 30 0.8 0.6 20 0.4 10 0.2 0 0.0 350 400 450 500 550 600 Wavelength λp (nm) 650 700 750 -40 -20 0 20 40 60 o 80 100 Ambient Temperature TA ( C) OPTEK reserves the right to make changes at any time in order to improve design and to supply the best product possible. Issue A.2 11/09 Page 8 of 9 OPTEK Technology Inc. — 1645 Wallace Drive, Carrollton, Texas 75006 Phone: (972) 323-2200 or (800) 341-4747 FAX: (972) 323-2396 [email protected] www.optekinc.com OPB780-Kit Color Sensor Evaluation Kit Possible Hook-up Schematic OPTEK reserves the right to make changes at any time in order to improve design and to supply the best product possible. OPTEK Technology Inc. — 1645 Wallace Drive, Carrollton, Texas 75006 Phone: (972) 323-2200 or (800) 341-4747 FAX: (972) 323-2396 [email protected] www.optekinc.com Issue A.2 11/09 Page 9 of 9