® OPT210 FPO MONOLITHIC PHOTODIODE AND AMPLIFIER 300kHz Bandwidth at RF = 1MΩ FEATURES DESCRIPTION ● BOOTSTRAP ANODE DRIVE: Extends Bandwidth: 900kHz (RF = 100KΩ) Reduces Noise ● LARGE PHOTODIODE: 0.09" x 0.09" The OPT210 is a photodetector consisting of a high performance silicon photodiode and precision FETinput transimpedance amplifier integrated on a single monolithic chip. Output is an analog voltage proportional to light intensity. ● HIGH RESPONSIVITY: 0.45A/W (650nm) ● EXCELLENT SPECTRAL RESPONSE ● WIDE SUPPLY RANGE: ±2.25 to ±18V The large 0.09" x 0.09" photodiode is operated at low bias voltage for low dark current and excellent linearity. A novel photodiode anode bootstrap circuit reduces the effects of photodiode capacitance to extend bandwidth and reduces noise. ● TRANSPARENT DIP, SIP AND SURFACEMOUNT PACKAGES ● BARCODE SCANNERS ● MEDICAL INSTRUMENTATION The integrated combination of photodiode and transimpedance amplifier on a single chip eliminates the problems commonly encountered with discrete designs such as leakage current errors, noise pick-up and gain peaking due to stray capacitance. ● LABORATORY INSTRUMENTATION ● POSITION AND PROXIMITY DETECTORS ● PARTICLE DETECTORS The OPT210 operates from ±2.25 to ±18V supplies and quiescent current is only 2mA. Available in a transparent 8-pin DIP, 8-lead surface-mount and 5-pin SIP, it is specified for 0° to 70°C operation. APPLICATIONS 5 λ (5) +1 8 (1) 3 (4) VO Infrared 0.5 Using External 1MΩ Resistor 0.4 0.4 0.3 0.3 0.2 0.2 0.1 0.1 Photodiode Responsivity (A/W) OPT210 Red Ultraviolet 0.5 2 (3) Voltage Output (V/µW) 1 (2) Blue V+ Green Yellow SPECTRAL RESPONSIVITY RF V– DIP Pins (SIP Pins) 0 100 200 300 400 500 600 0 700 800 900 1000 1100 Wavelength (nm) International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111 Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132 ® 1 PDS-1313B OPT210 SPECIFICATIONS At TA = +25°C, VS = ±15V, λ = 650nm, External RF = 1MΩ, RL = 10kΩ, unless otherwise noted. OPT210P OPT210W PARAMETER CONDITIONS RESPONSIVITY Photodiode Current Unit-to-Unit Variation Voltage Output Nonlinearity Photodiode Area DARK ERROR, RTO Offset Voltage vs Temperature vs Power Supply Voltage Noise FREQUENCY RESPONSE Bandwidth Rise Time Settling Time, 1% 0.1% 0.01% Overload Recovery OUTPUT Voltage Output, Positive Positive Negative(1) Capacitive Load, Stable Operation Short-Circuit Current(2) MIN λ = 650nm TYP (0.09 x 0.09in) (2.29 x 2.29mm) 0.45 ±5 0.45 0.01 0.008 5.2 VS = ±2.25V to ±18V BW = 0.01Hz to 100kHz ±2 ±35 100 160 λ = 650nm, External RF = 1MΩ External RF = 1MΩ 10% to 90% FS to Dark step 100% Overdrive RL = 10kΩ RL = 5kΩ RL = 10kΩ (V+)–1.25 –0.4 POWER SUPPLY Operating Range Quiescent Current UNITS A/W % V/µW % of FS in2 mm2 ±10 1000 mV µV/°C µV/V µVrms 300 1.2 3 8 20 7 kHz µs µs µs µs µs (V+)–0.75 (V+)–1 –0.5 500 +50 V ±2.25 +2.0/–1.7 TEMPERATURE RANGE Specification Operating Storage θJA MAX 0 0 –25 V pF mA ±18 ±4 V mA 70 70 85 °C °C °C °C/W 100 NOTES: (1) Output typically swings to 0.5V below the voltage applied to the non-inverting input terminal, which is normally connected to ground. (2) Positive current (sourcing) is limited. Negative current (sinking) is not limited. PHOTODIODE SPECIFICATIONS PHOTODIODE PARAMETER CONDITIONS Photodiode Area Current Responsivity Dark Current vs Temperature Capacitance Effective Capacitance(1) MIN (0.09 x 0.09in) (2.29 x 2.29mm) λ = 650nm TYP 0.008 5.2 0.45 865 70 Doubles every 10°C 550 10 VD = –1.2V VD = –1.2V VD = –1.2V MAX UNITS in2 mm2 A/W µA/W/cm2 pA pF pF NOTES: (1) Effect of photodiode capacitance is reduced by internal buffer bootstrap drive. See text The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant any BURR-BROWN product for use in life support devices and/or systems. ® OPT210 2 OP AMP SPECIFICATIONS Op amp specifications provided for comparative information only. OP AMP PARAMETER CONDITIONS MIN INPUT Offset Voltage vs Temperature vs Power Supply Input Bias Current Inverting Input vs Temperature Non-inverting Input TYP MAX UNITS ±2 ±35 100 mV µV/°C µV/V 15 Doubles every 10°C 300 pA 20 9 6 0.8 nV/√Hz nV/√Hz nV/√Hz fA/√Hz INPUT VOLTAGE RANGE Common-Mode Input Range(1) Common-Mode Rejection VS±2.25 65 V dB INPUT IMPEDANCE Inverting Input Impedance Non-Inverting Input Impedance 3x1010||3 250 Ω || pF kΩ 70 dB 35 25 240 390 800 7 MHz ns ns ns ns µs (V+)–0.75 (V+)–1 –0.5 500 +50 V NOISE Voltage Noise f = 10Hz f = 100Hz f = 1kHz Current Noise Density, Inverting Input OPEN-LOOP GAIN Open-Loop Voltage Gain FREQUENCY RESPONSE Bandwidth, Small Signal Rise Time, Large Signal Settling Time, 1% 0.1% 0.01% Overload Recovery BW = 0.01Hz to 100kHz VO = 0V to +13.75V 10% to 90% 10V step 100% Overdrive OUTPUT Voltage Output, Positive Positive Negative(1) Capacitive Load, Stable Operation Short-Circuit Current(2) RL = 10kΩ RL = 5kΩ RL = 10kΩ (V+)–1.25 –0.4 POWER SUPPLY Operating Voltage Quiescent Current ±2.25 +1.7/–1.4 µA V pF mA ±18 ±4 V mA NOTES: (1) Output typically swings to 0.5V below the voltage applied to the non-inverting input terminal, which is normally connected to ground. (2) Positive current (sourcing) is limited. Negative current (sinking) is not limited. BUFFER SPECIFICATIONS Buffer specifications provided for comparative information only. BUFFER PARAMETER CONDITIONS MIN INPUT Offset Voltage(1) Input Bias Current vs Temperature Input Impedance TYP MAX UNITS –1.2 15 Doubles every 10°C 1011||3 Ω || pF FREQUENCY RESPONSE Bandwidth, Small Signal 500 MHz OUTPUT Current Voltage Gain ±200 0.99 µA V/V POWER SUPPLY Operating Range Quiescent Current ±2.25 ±0.3 V pA ±18 V mA NOTE: (1) Intentional voltage offset to reverse bias photodiode. ® 3 OPT210 ELECTROSTATIC DISCHARGE SENSITIVITY PIN CONFIGURATIONS Top View DIP V+ 1 8 Common –In 2 7 NC 6 NC 5 Output V– 3 NC 4 (1) This integrated circuit can be damaged by ESD. Burr-Brown recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. NOTE: (1) Photodiode location. Top View SIP Common 1 V+ 2 –In 3 V– 4 Output 5 (1) MOISTURE SENSITIVITY AND SOLDERING NOTE: (1) Photodiode location. Clear plastic does not contain the structural-enhancing fillers used in black plastic molding compound. As a result, clear plastic is more sensitive to environmental stress than black plastic. This can cause difficulties if devices have been stored in high humidity prior to soldering. The rapid heating during soldering can stress wire bonds and cause failures. Prior to soldering, it is recommended that plastic devices be baked-out at 85°C for 24 hours. ABSOLUTE MAXIMUM RATINGS Supply Voltage ................................................................................... ±18V Input Voltage Range (Common Pin) .................................................... ±VS Output Short-Circuit (to ground) ............................................... Continuous Operating Temperature: P, W ........................................... –25°C to +85°C Storage Temperature: P, W ........................................... –25°C to +85°C Junction Temperature: P, W .......................................................... +85°C Lead Temperature (soldering, 10s) ................................................ +300°C (Vapor-Phase Soldering Not Recommended on Plastic Packages) The fire-retardant fillers used in black plastic are not compatible with clear molding compound. The OPT210 plastic packages cannot meet flammability test, UL-94. PACKAGE INFORMATION PRODUCT PACKAGE PACKAGE DRAWING NUMBER(1) OPT210P OPT210P-J OPT210W 8-Pin Plastic DIP 8-Lead Surface Mount(2) 5-Pin Plastic SIP 006-5 006-6 321-1 NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. (2) 8-pin DIP with leads formed for surface mounting. ® OPT210 4 TYPICAL PERFORMANCE CURVES At TA = +25°C, VS = ±15V, λ = 650nm, unless otherwise noted. NORMALIZED SPECTRAL RESPONSIVITY VOLTAGE RESPONSIVITY vs RADIANT POWER 10 (0.48A/W) 0.8 650nm (0.45A/W) Output Voltage (V) Normalized Current or Voltage Output 1.0 0.6 0.4 Ω M 1 RF = 10 Ω RF 0.1 = 1M 0k RF = Ω 10 0.01 kΩ RF 0.2 = 10 Ω RF = 1k λ = 650nm 0.001 0 100 200 300 400 500 600 700 800 900 1000 1100 0.01 0.1 1 Wavelength (nm) 10 100 1k Radiant Power (µW) VOLTAGE OUTPUT RESPONSIVITY vs FREQUENCY VOLTAGE RESPONSIVITY vs IRRADIANCE 100 10 Ω 1 RF = M 10 0.1 Responsivity (V/µW) Output Voltage (V) RF = 100MΩ Ω RF = 1M kΩ RF = 0 10 0.01 kΩ RF = 10 RF = Ω 1k RF = 1MΩ, CF = 0.5pF 1 RF = 100kΩ, CF = 1.8pF 0.1 λ = 650nm 0.001 0.01 0.001 0.01 0.1 1 10 1k 100 POWER SUPPLY REJECTION vs FREQUENCY SIP Package 80 0.8 θY 0.6 θX Plastic DIP Package θY 0.4 0.2 0.2 10M 90 θX θY 0.6 0.4 1M RESPONSE vs INCIDENT ANGLE Power Supply Rejection (dB) θX 100k Frequency (Hz) 1.0 0.8 10k Irradiance (W/m2) 1.0 Relative Response RF = 10MΩ 10 70 60 V– 50 40 30 20 V+ 10 0 0 0 ±20 ±40 ±60 –10 0 ±80 1 10 100 1k 10k 100k 1M 10M Frequency (Hz) Incident Angle (°) ® 5 OPT210 TYPICAL PERFORMANCE CURVES (CONT) At TA = +25°C, VS = ±15V, λ = 650nm, unless otherwise noted. OUTPUT NOISE VOLTAGE vs MEASUREMENT BANDWIDTH QUIESCENT CURRENT vs TEMPERATURE 10–2 IQ– Noise Voltage (Vrms) 2 VS = ±15V IQ+ 1 Dashed lines indicate noise measured beyond the signal bandwidth. 10–3 IQ+ IQ– VS = ±2.25V RF = 10MΩ 10–4 RF = 100MΩ 10–5 RF = 100kΩ 10–6 RF = 10kΩ RF = 1MΩ 10–7 0 –75 –50 –25 0 25 50 75 100 10 125 100 1k 10k 100k 1M Temperature (°C) Frequency (Hz) SMALL-SIGNAL RESPONSE, RF = 1MΩ Measurement BW = 1MHz LARGE-SIGNAL RESPONSE, RF = 1MΩ 2V/div 20mV/div 5µs/div 5µs/div NOISE EFFECTIVE POWER vs MEASUREMENT BANDWIDTH RF = 10kΩ 10–7 Dashed lines indicate noise measured beyond the signal bandwidth. λ = 650nm 10–8 Noise Effective Power (W) Quiescent Current (mA) 3 RF = 100kΩ RF = 1MΩ RF = 10MΩ 10–9 RF = 100MΩ 10–10 10–11 10–12 10–13 10–14 10 100 1k 10k 100k Frequency (Hz) ® OPT210 6 1M 10M 10M APPLICATIONS INFORMATION The typical performance curve “Output Voltage vs Radiant Power” shows the response throughout a wide range of radiant power and feedback resistor values. The response curve “Output Voltage vs Irradiance” is based on the photodiode area of 5.23x10–6m2. Basic operation of the OPT210 is shown in Figure 1. Power supply bypass capacitors should be connected near the device pins as shown. Noise performance of the OPT210 can be degraded by the high frequency noise on the power supplies. Resistors in series with the power supply pins as shown can be used (optional) to help filter power supply noise BOOTSTRAP BUFFER The photodiode’s anode is driven by an internal high speed voltage buffer shown in Figure 1. This variation on the classical transimpedance amplifier circuit reduces the effects of photodiode capacitance. The effective photodiode capacitance is reduced from approximately 550pF to 10pF with this bootstrap drive technique. This improves bandwidth and reduces noise. An external feedback resistor, RF, is connected from –In to the VO terminal as shown in Figure 1. Feedback resistors of 1MΩ or less require parallel capacitor, CF. See the table of values in Figure 1. (paracitic capacitance) The output voltage of the buffer is offset approximately 1.2V below the input. This reverse biases the photodiode for reduced capacitance. +15V For RF > 2MΩ, use series-connected resistors. See text. CF 1µF + 100Ω 1 (2) OP AMP A special op amp design is used to achieve wide bandwidth. The op amp output voltage cannot swing lower than 0.5V below the non-inverting input voltage. Since photodiode current always produces a positive output voltage, this does not limit the required output swing. RF 2 (3) OPT210 5 λ (5) +1 8 (1) 3 The inverting input is designed for very low input bias current—approximately 15pA. The non-inverting input has much larger bias current—approximately 300µA flows out of this terminal. (4) 100Ω Optional series resistors filter power supply noise. See text. VO (0V to 14V) + 1µF +15V –15V RF CF (min) BANDWIDTH 10MΩ 1MΩ 100kΩ 10kΩ 1kΩ (1) 0.5pF 1.8pF 10pF 20pF 70kHz 300kHz 900kHz 1.6MHz 1.6MHz RF 0.1µF 1 (2) 2 (3) 1MΩ OPT210 5 λ NOTE: (1) Two series-connected resistors of RF /2 for low capacitance. See text. +1 VO Output voltage offset by VA +15V FIGURE 1. Basic Operation. (5) 8 (1) 3 (4) 300µA 0.1µF 100µA 1/2 REF200 Bandwidth varies with feedback resistor value. To achieve widest bandwidth with resistors greater than 1MΩ, use care to minimize parasitic parallel capacitance. For widest bandwidth with resistors greater than 2MΩ, connect two resistors (RF/2) in series. Airwiring this interconnection provides lowest capacitance. Although the OPT210 is usable with feedback resistors of 100MΩ and higher, with RF ≥ 10MΩ the model OPT211 will provide lower dc errors and reduced noise. –15V 200Ω 200Ω OPA131 VA ±20mV 10kΩ 100µA 1/2 REF200 –15V The OPT210’s output voltage is the product of the photodiode current times the external feedback resistor, RF. Photodiode current, ID, is proportional to the radiant power or flux (in watts) falling on the photodiode. At a wavelength of 650nm (visible red) the photodiode Responsivity, RI, is approximately 0.45A/W. Responsivity at other wavelengths is shown in the typical performance curve “Responsivity vs Wavelength.” FIGURE 2. Adjustable Output Offset. An offset voltage can be connected to the non-inverting input as shown in Figure 2. A voltage applied to the noninverting input is summed at the output. Because the noninverting input bias current is high (approximately 300µA), it should be driven by a low impedance such as the bufferconnected op amp shown. ® 7 OPT210 cosine of the incident angle). At a greater incident angle, light is diffused by the side of the package. These effects are shown in the typical performance curve, “Response vs Incident Angle.” The OPT210 can be connected to operate from a single power supply as shown in Figure 3. The non-inverting input bias current flows through a zener diode to provide a bias voltage. The output voltage is referenced to this bias point. LINEARITY PERFORMANCE Photodiode current is very linear with radiant power throughout its range. Nonlinearity remains below approximately 0.01% up to 200µA. The anode buffer drive, however, is limited to approximately 200µA. This produces an abrupt limit to photodiode output current when radiant power reaches approximately 450µW. +15V RF 0.1µF 1 (2) 2 (3) VO measured relative to 5.6V zener voltage. OPT210 5 λ (5) +1 VO Best linearity is achieved with the photodiode uniformly illuminated. A light source focused to a very small beam, illuminating only a small percentage of the photodiode area, may produce a higher nonlinearity. (5.6V) 8 (1) ≈300µA ZD1 3 (4) + 1µF ZD1: IN4626 5.6V specified at IZ = 250µA NOISE PERFORMANCE Noise performance of the OPT210 is determined by the op amp characteristics in conjunction with the feedback components, photodiode capacitance, and buffer performance. The typical performance curve “Output Noise Voltage vs Measurement Bandwidth” shows how the noise varies with RF and measured bandwidth (0.1Hz to the indicated frequency). The signal bandwidth of the OPT210 is indicated on the curves. Noise can be reduced by filtering the output with a cutoff frequency equal to the signal bandwidth. FIGURE 3. Single Power Supply Operation. DARK ERRORS The dark errors in the specification table include all sources with RF = 1MΩ. The dominant error source is the input offset voltage of the op amp. Photodiode dark current is approximately 70pA and the combined input bias current of the op amp and buffer is approximately 30pA. Photodiode dark current and input bias current total approximately 100pA at 25°C and double for each 10°C above 25°C. At 70°C, the total error current is approximately 2nA. With RF = 1MΩ, this would produce a 2mV offset voltage in addition to the initial amplifier offset voltage (10mV max) at 25°C. The dark output voltage can be trimmed to zero with the optional circuit shown in Figure 2. Output noise increases in proportion to the square-root of the feedback resistance, while responsivity increases linearly with feedback resistance. So best signal-to-noise ratio is achieved with large feedback resistance. This comes with the trade-off of decreased bandwidth. The noise performance of a photodetector is sometimes characterized by Noise Effective Power (NEP). This is the radiant power which would produce an output signal equal to the noise level. NEP has the units of radiant power (watts), or Watts/√Hz to convey spectral information about the noise. The typical performance curve “Output Noise Voltage vs Measurement Bandwidth” is also scaled for NEP on the right-hand side. LIGHT SOURCE POSITIONING The OPT210 is tested with a light source that uniformly illuminates the full integrated circuit area, including the op amp. Although all IC amplifiers are light sensitive to some degree, the OPT210 op amp circuitry is designed to minimize this effect. Sensitive junctions are shielded with metal where possible. Furthermore, the photodiode area is very large compared to the op amp circuitry making these effects negligible. If your light source is focused to a small area, be sure that it is properly aimed to fall on the photodiode. If a narrowly focused light source were to miss the photodiode and fall on the op amp circuitry, the OPT210 would not perform properly. The large photodiode area is clearly visible as a very dark area slightly offset from the center of the IC. The incident angle of the light source also affects the apparent sensitivity in uniform irradiance. For small incident angles, the loss in sensitivity is due to the smaller effective light gathering area of the photodiode (proportional to the ® OPT210 8