"Improving the Quality of Life through the Power in Light" Planar Silicon Photodiodes ...photovoltaic & photoconductive... QUANTUM DEVICES, INC. offers two high quality, state of the art, photodiode constructions: Photovoltaic for (PV) application and Photoconductive for (PC) applications. Due to the high quality of our design the two series can be used in both photovoltaic and photoconductive modes. 3/4 The PV series is slightly lower in dark current while designed to minimize the internal series resistance to enhance the linearity of illumination response levels well into the forward biased operation point. 3/4 The PC series is designed to provide a low junction capacitance while providing excellent dark current parameters. The PC series will also provide improved farred spectral response. PHOTOVOLTAIC AND PHOTOCONDUCTIVE OPERATION When a photodiode is operated in a photovoltaic mode, the photodiode is unbiased. During the time that the photodiode operates with a reverse bias voltage, the operating mode is considered photoconductive. Figure 2 shows a typical I-V curve for a silicon photodiode. This graph indicates the increase in relative current to the increase in illumination at V=0 (short circuit current). The illumination curves are linear to input light intensity until the photodiode becomes forward biased, at this point the generated current starts to flow through the diode. Photodiode open circuit voltage is where I=0 on the illumination curve (diode is forward biased) and varies as the logarithm of the illumination level. Both the photovoltaic load (PV) and the photoconductive (PC) load lines are indicated in figure 2 as well. As shown, the PV load line indicates a linear current vs. illumination is generated for illuminations L=1 and L=2; while the PV load line indicates a nonlinear current vs. illumination for L=3 and L=4 as the diode becomes forward biased. The PC load line will maintain a linear current vs. illumination for all illumination levels. +I -V +V L=1 L=2 L=3 L=4 PV Load Line PC Load Line L= Illumination I= Current generated from the photodiode Load Line = I/RLoad -I Figure 2 ...features... 3/4 Linearity Over a Wide Dynamic Range 3/4 Broad Spectral Response 3/4 Excellent Responsivity PC Low Capacitance Low Dark Current PV High Shunt Resistance Low Noise Figures 3a and 3b are typical for photovoltaic operation. Photovoltaic applications are designed for low noise (reduced dark currents) and the frequency response of figure 3a will be dependant on load resistance and the shunting impedance of the photodiode junction capacitance [1/(2FC)]. The circuit shown in figure 3b illustrates a transimpedance amplifier. This amplifier will clamp the photodiode voltage bias to zero volts. The resultant effective impedance seen by the junction capacitance will be very low yielding excellent frequency response. Figures 4a and 4b illustrate circuits typical for photoconductive applications. A photoconductive mode of operation will enhance the photodiode speed requirements as the junction capacitance is reduced with increase in reverse bias. The reverse bias will generate a dark current proportional to the bias voltage and should be evaluated for the particular application. The circuits in Figure 4 are similar to the Figure 3 above, except the photodiodes are operated with a reverse bias. 1cm Series 1cm x 2cm 1cm x 1cm 1cm x .5cm Series Type .25cm Series .5cm Series .5cm x 2.0cm .5cm x 1.0cm .5cm x .5cm .5cm x .25cm .394 x .787 .394 x .394 .394 x .197 Part Number Part Number Total Act. Area Chip Dimen. Wire Bond Contact Solderable Contact (mm) P.V. P.V. P.V. P.V. P.V. P.V. P.V. P.V. P.V. P.V. P.V. P.V. 2010A004 2010A005 2010A006 2010A007 2010A008 2010A009 2010A010 2010A011 2010A012 2010A013 2010A014 2010A015 2012A004 2012A005 2012A006 2012A007 2012A008 2012A009 2012A010 2012A011 2012A012 2012A013 2012A014 2012A015 P.C. P.C. P.C. P.C. P.C. P.C. P.C. P.C. P.C. P.C. P.C. P.C. 2011A004 2011A005 2011A006 2011A007 2011A008 2011A009 2011A010 2011A011 2011A012 2011A013 2011A014 2011A015 2013A004 2013A005 2013A006 2013A007 2013A008 2013A009 2013A010 2013A011 2013A012 2013A013 2013A014 2013A015 .25cm x 2.0cm .25cm x 1.0cm .25cm x .5cm .25cm x .25cm .25cm x .125cm .197 x .787 .197 x .394 .197 x .197 .197 x .098 Dark Current At -5V Responsivity @880nm Shunt Resistance (in) (min) (mA) (min) (M-Ohm) Typ. (nA) Max. (nA) at OV (pF) at 3V (pF) 175 86.4 42.1 76.2 37.7 18.3 8.63 26.6 13.1 6.40 3.00 1.33 .394 x .787 .394 x .394 .394 x .197 .197 x .787 .197 x .394 .197 x .197 .197 x .098 .098 x .787 .098 x .394 .098 x .197 .098 x .098 .098 x .049 .55 .55 .55 .55 .55 .55 .55 .55 .55 .55 .55 .55 750 1,500 3,000 1,500 3,000 6,00 12,000 3,000 6,000 12,000 24,000 48,000 1.30 .660 .330 .660 .330 .166 .083 .330 .166 .083 .050 .020 13.0 6. 3.3 6.6 3.3 1.66 .83 3.3 1.66 .83 .50 .20 20,400 10,100 4,900 9,900 4,900 2,400 1,130 4,700 2,300 1,130 530 235 8,160 4,000 2,000 4,000 2,000 960 450 1,900 930 450 210 94 175 86.4 42.1 76.2 37.7 18.3 8.63 26.6 13.1 6.40 3.00 1.33 .394 x .787 .394 x .394 .394 x .197 .197 x .787 .197 x .394 .197 x .197 .197 x .098 .098 x .787 .098 x .394 .098 x .197 .098 x .098 .098 x .049 .55 .55 .55 .55 .55 .55 .55 .55 .55 .55 .55 .55 30 60 120 60 120 240 480 120 240 480 960 1,920 33.0 17.0 8.30 17.0 8.30 4.20 2.10 8.30 4.20 2.10 1.00 .55 333 170 83.0 170 83.0 42.0 21.0 83.0 42.0 21.0 10.0 5.5 2500 1240 600 1220 600 290 140 575 280 140 65 29 950 470 230 460 229 112 52 218 108 52 25 11 (c) Quantum Devices, Inc. 1998. All rights reserved Capacitance (typ) .098 x .787 .098 x .394 .098 x .197 .098 x .098 .098 x .049 Contact your QDI Representative for more information.... 112 Orbison, P.O. Box 100 Barneveld, WI 53507 *(608)924-3000 *fax: (608)924-3007 www.QuantumDev.com email: QDISALES@quantumdev.com "Improving the Quality of Life through the Power in Light"