PD150 SHARP | Alldatasheet

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SHARP ELEK/ MELEC DIV 15E 0 | 8180798 0002711 0 I Color Sensors PD150/PD151 a —— To HSI PD150/PD151 10-18 Type Color Sensor M@ Features ™ Outline Dimensions (Unit : mm) 1, Output corresponding to the wavelength of g4.7e01 light = 2. Compact 1-chip structure an 3, Blue to near infrared light range zl x 4, Infrared cut-off type : PD151 | 9) dottok ® ™@ Applications | ] | Nd lp PDI 1. Color reading el j - Automatic white balancing for VCR “ | | | @ cameras £045 Pp2 + Flame color meter for fan heaters yy > | + Color identification for color paper 2» + Chromatic balance adjustment for TVs Y © © @ 2. Color temperature/wavelength reading N aan ® + Measurement and control for color temper- OF 9) ature/wavelength of light source ye LY) . 45" Ge ® Anode ® Cathode Marking of PDIS1 is BOIS). @ Anode ™@ Absolute Maximum Ratings (Ta=25°C) Parameter Unit Reverse voltage | Vs |__| V Operating temperature c Storage temperature c %1 For 10 seconds at the position of 1.3mm from the bottom face of can package ™@ Electro-optical Characteristics (Ta=25°C) Parameter [Symbol __Conditions__— MIN. [ TYP. [ MAX. [ Unit Darke current [a twat P| 0 ma . , , [| Cu [Va=0f=IMHz | = [200 | = oF Terminal capactance [Ga [Va50,fS1MHe =| a0 =o ircuit [PDi51 | E-=504W/em* | — | 06 [ — [ua [poisi | Ee=50,W/em? [= Peis Pua a SHARP 137

: SHARP ELEK/ MELEC DIV LSE D | 8180798 OO0e?le 2 I : Color Sensors . PD150/PD151 i ee j @ Theory of Operation Fig. 1 Structure of Semiconductor The semiconductor color sensor PD150 is Color Sensor T-41-51 an element of two PN-junctions (photodiode) Electrode ~ vertically incorporated into one chip with its inguation sim electrode ® y Z . thickness of silicon acting as an optical filter. Y This means, as shown in Fig. 2, that with the SS SSS Photodiode PD! lights of short wavelength absorbed near the L-ase | ® surface of silicon and those of long wavelength peed going deeper to be absorbed, the photodiode Photodiode PD2-Y” NN PD1 of the less deep PN-junction will have Electrode @ ® greater sensitivity to short wavelength lights ‘ while the photodiode PD2 of the deeper PN- (2 Structure Ope junction will have greater sensitivity to long | wavelength lights. These characteristics are i shown in Fig. 3. According to this spectral sensitivity, as a signal processing method for picking up a signal (color signal) corresponding to its wave- _— Fig. 2. Wavelength and Light length of light, the short circuit current ratio Absorbtion Areas between the two photodiodes above mentioned Blue Red Infrared | is used. From Fig. 3, the relationship between the [__?Piayer J short circuit current ratio (Isc/Isc:) and the [eT] wavelength of the incident light (A) can be obtained as shown in Fig. 5. As it is obvious in this figure, there is the 1-to-1 correspondence between one wavelength and the short circuit current ratio to indicate that the reading of } color of light (wavelength) is possible. Thus, the wavelength of blue to near infra- red color can be read by PD150, Also taken into account to make the color signal reading capability as close to that of human eye as possible is the fact the human eye is insensitive to wavelength of over 700nm. Fig. 3 Spectral Sensitivity (PD150) Hence the PD151 which is a PD150 with 100 built-in infrared cut-off filter. Its spectral sen- x sitivity characteristics are shown in Fig. 4. ere tt Next, concretely described in Fig. 3, Fig. 4 g i A and Fig. 5 will be a case with a monochromatic 5 «19 || light striking upon the semiconductor color = 4 PT N/7 {| | VW | sensor and a case with a composite light of a w A | Al | VY various wavelength striking upon it. sZt TAN Th 2o¢ 1 [7 AL NI 2g | IT IN IN ONT ool | | TS) 400 500 600 700 800 900 1000 1100 Wavelength A (nm) 138

a SHARP ELEK/ MELEC DIV 15€ 0 ff 4180798 oo02723 4 ff , | PD151 Color Sensors 1-41-51 PD150, | (1) When a monochromatic light of wave. ‘Fig. 4 Spectral Sensitivity (PD151) ! length (A =500nm) strikes upon it : 109 In the case with the PD150, the short circuit current ratio of PD1 to PD2 to be Aer te obtained from Fig. 3: g 80 CAT Too Isc2/Tser = 0.020C,/0.580C, = 0.034 2 10 (C; ! constant) ot Nt tT | tf corresponds to the short circuit current ratio soy Vt tt shown in Fig. 5 | ‘The similar result can be obtained with 2 “( [ [VT ft {_[_| | PD1651 from Fig. 4 and Fig.5.However,in 3 “7 [| VF [ [ f_| the case of near infrared light striking upon. 1 tn7A NTT Td it even though it is monochromatic as in the 10) 7 above case, the PD150 with no infrared oe I A. ight cut-off filter incorporated is more | effective than the PD151 because of its Wavelength 2 (om) 1 greater sensitivity in the near infrared zone. : (2) When a composite light of various wave- Fig. 5 Short Circuit Current Ratio vs. ; lengths (visible and near infrared) Wavelength (PD150, PD151) i strikes upon it = = SSS 4 | Suppose the incident light is made up of 5 ——— a light (A) : wavelength 4,=500nm, er ee | an | ree ctmMien §=— 8 Le and 2 ES a light (B) : wavelength 4»=800nm, & Eraweorc—-—t+—_ | | irradiance E,,=3.0mW/cm? FI TALI The human eye will recognize this in- = == ciedent light as of about 500nm wavelength § 0.05 === . while this semiconductor color sensor will 0.02 a . recognize the same light as follows. a a i i) With the PD151 : C= —— ; ‘The short circuit current for PDI and 100 ety : PD2, from Fig. 4, is favelength 2 (nm) ! Tse1 = (5 0.900 +3 X 0,010)C2 = 4.530C2 (Ce: constant) srs Fig. 6 Block Diagram of a Sample Signal Isce = (5X 0.031 +3 X0,020)C; =0.215C, Processing Circuit (Cy: constant) «sess Q) From the equations @ and @, the short Logarithmic i circuit current ratio can be obtained. su : Thus, PD? SDH scr traction Isce/Iscs = 0.047. cS. Logarithmic [tT }eov, So the wavelength that corresponds to aN ; ~ the short circuit ratio of 0.047, accord- pr —— Cutpat volage Fa ing to Fig. 5, is A=510nm, which the iH PD151 recognizes. i ii) With the PD150: i In the same way as in i), from Fig. 3 and \\ Fig. 5, 2=680nm will be obtained. So the wavelength whci the PD150 recog: ! nizes is A=680nm. | SS SHRP H 139 t