ISL29000 ® Data Sheet September 2, 2008 FN6117.6 Ambient Light Photo Detect IC Features The ISL29000 is a light-to-current optical sensor combining a photodiode and a current amplifier on a single monolithic IC. Output current is directly proportionate to the light intensity on the photodiode. Its sensitivity is superior to that of a phototransistor and exhibits little variation. Its spectral sensitivity matches closely to the luminous efficiency and linearity. • Monolithic IC containing photodiode and amplifier Housed in an ultra-compact surface mount clear plastic package, this device is excellent for power saving control function in cell phones, PDAs, and other handheld applications. • Ultra-compact and light surface mount package Pinout • Mobile phones • Converts light intensity to current • 2.5V to 5.5V supply range • Low supply current: 1µA • Excellent output linearity of luminance • Pb-free (RoHS compliant) Applications • Notebook PCs ISL29000 (5 LD ODFN) TOP VIEW • PDAs • Video cameras VCC 1 GND 2 5 OUTPUT THERMAL PAD • Digital cameras Ordering Information 4 NC EN 3 *THERMAL PAD CAN BE CONNECTED TO GND OR ELECTRICALLY ISOLATED PART NUMBER (Note) ISL29000IROZ-T7* TEMP RANGE (°C) -40 to +85 PACKAGE (Pb-Free) PKG. DWG. # 5 Ld ODFN L5.2X2.1 Tape and Reel ISL29000IROZ-EVALZ Evaluation Board *Please refer to TB347 for details on reel specifications. NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate - e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright © Intersil Americas Inc. 2005-2008. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. ISL29000 Absolute Maximum Ratings (TA = +25°C) Thermal Information Supply Voltage between VSD and GND . . . . . . . . . . . . . . . . . . . .6V Maximum Continuous Output Current . . . . . . . . . . . . . . . . . . . . 6mA Operating Temperature . . . . . . . . . . . . . . . . . . . . . . .-40°C to +85°C Thermal Resistance θJA (°C/W) ODFN Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Maximum Die Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . +90°C Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +100°C Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA VCC = 3V, TA = +25°C, unless otherwise specified. Electrical Specifications PARAMETER ICC DESCRIPTION CONDITION Supply Current MIN TYP MAX UNIT RL = 1kΩ, EV = 1000 lux 74 µA EV = 0 0.2 µA IL1 Light Current EV = 1000 lux IL2 Light Current EV = 100 lux 6.5 µA ILEAK Dark Current EV = 0 0.06 µA Maximum Output Compliance Voltage At 95% of normal output current, EV = 1000 lux 2.7 V tR Rise Time (Note 1) RL = 5kΩ, EV = 1000 lux 27 µs tF Fall Time (Note 1) RL = 5kΩ, EV = 1000 lux 78 µs tD Delay Time for Rising Edge (Note 1) RL = 5kΩ, EV = 1000 lux 80 µs tS Delay Time for Falling Edge (Note 1) RL = 5kΩ, EV = 1000 lux 35 µs VO(MAX) VLO Maximum Voltage at EN Pin to Enable VHI Minimum Voltage at EN Pin to Disable 45 61 75 0.6 1.8 µA V V NOTE: 1. Switching time measurement is based on Figures 1 and 2. 2. Fluorescent light is substituted by Green LED during production. PULSE DRIVE CH1 tD VCC 1V PULSE DRIVE ISL29000 80% 0.1V RL CH2 VOUT tR 2 tS VS = 3V tA = +27°C VOUT FIGURE 1. RISE/FALL TIME MEASUREMENT 100µs 20% tF FIGURE 2. RISE/FALL TIME MEASUREMENT WAVEFORMS FN6117.6 September 2, 2008 ISL29000 Typical Performance Curves 70 ISL29000 RELATIVE RESPONSE VCC = 3V FLUORESCENT LIGHT 60 OUTPUT CURRENT (µA) RELATIVE RESPONSE (%) 100 80 60 40 ISL29000 RELATIVE RESPONSE WITH IR GLASS FILTER 20 50 40 30 20 10 0 0 400 500 600 700 800 900 0 1k 200 WAVE LENGTH (nm) 0.20 1000 1.20 VDD = 3V VDD = 3V 1.15 FLUORESCENT LIGHT OF 500 LUX 0.18 0.16 0.14 1.10 1.05 1.00 0.95 0.90 0.12 0.85 0.10 -60 -40 -20 0 20 40 60 80 0.80 -60 100 -40 -20 TEMPERATURE (°C) 20 40 60 80 100 FIGURE 6. GAIN vs TEMPERATURE 800 0.6 0.5 0 TEMPERATURE (°C) FIGURE 5. DARK CURRENT vs TEMPERATURE VDD = 3V TA = +27°C 700 600 0.4 IOUT (µA) OUTPUT COMPLIANCE VOLTAGE (VDD - VOUT) (V) 800 FIGURE 4. SENSITIVITY GAIN/GAIN (+25°C) OUTPUT CURRENT - NO LIGHT (µA) FIGURE 3. SPECTRAL RESPONSE 400 600 ILLUMINATION (LX) 0.3 0.2 500 400 FLUORESCENT LIGHT SOURCE 300 200 0.1 0 -200 100 0 0 200 400 600 800 1000 1200 OUTPUT CURRENT (µA) FIGURE 7. OUTPUT COMPLIANCE VOLTAGE vs CURRENT 3 0 5k 10k 15k 20k ILLUMINANCE (lux) FIGURE 8. IOUT vs LUMINANCE FN6117.6 September 2, 2008 ISL29000 For some applications, a load resistor is added between the output and the ground as shown in Figure 1. The output voltage can be expressed in Equation 2: Pin Descriptions PIN NAME DESCRIPTION 1 VCC Supply, 2.5V to 5.5V 2 GND Ground 3 EN Enable 4 NC No connect 5 Output 61μA V OUT = I OUT × R LOAD = ⎛ ------------------------⎞ × L INPUT × R LOAD ⎝ 1000Lux⎠ (EQ. 2) Here, VOUT is the output voltage and RLOAD is the value of the load resistor added. The compliance of the ISL29000's output circuit may result in premature saturation of the output current and voltage when an excessively large RLOAD is used. The output compliance voltage is 300mV below the supply voltage as listed in VO(MAX) of “Electrical Specifications” on page 2. Current output pin Block Diagram VCC 1 In order to have the linear relationship between the input light and the output current and voltage, a proper resistor value (i.e., gain) should be picked for a specific input light range. The resistor value can be picked according to Equation page 4: 3 ENABLE ( V SUP – 0.3V ) 1000Lux - × -----------------------R LOAD = -------------------------------------· L RANGE 61 μA 5 (EQ. 3) OUTPUT Here, VSUP is the supply voltage, and LRANGE is the specific input light range for an application. For example, an indoor light ranges typically from 0 lux to 1,000 lux. A resistor value of 45kΩ for 3V supply voltage can be used. For a small light range, a large resistor value should be used to achieve better sensitivity; for a large light range, a small resistor value should be used to prevent non-linear output current and voltage. 2 GND Application Information Product Description Resistor Output RLOAD Selection The ISL29000 is a light-to-current optical sensor combining photodiodes and current amplifiers on a single monolithic IC. The photodiodes are temperature-compensated and their spectrum resembles the human eye response. The output current is directly proportional to the intensity of light falling on the photodiodes. For 100 lux of input fluorescent light, the ISL29000 has an output current of 6.5µA. The resistor output, RLOAD, determines the voltage transfer function of the device. The device converts light into current then RLOAD converts the output current to an output voltage. RLOAD can range from 10Ω to 10MΩ depending on the input lux levels. The table below lists RLOAD values to maximize output swing for typical lux range levels. A careful balance of dynamic swing and fast response has to be considered when choosing RLOAD. For faster response, choose a smaller value RLOAD to shunt stray capacitances that may slow down response time. For maximum dynamic range or swing, choose a higher value RLOAD. Although finite, the output impedance of the device is considerably large. Hence, the light-to-current conversion deviation because of resistor loading is infinitesimal. The recommended maximum RLOAD is 10MΩ. The ISL29000 is housed in an ultra-compact surface mount clear plastic package. Light-to-Current and Voltage Conversion The ISL29000 has a responsiveness that is directly proportional to the intensity of light intercepted by the photodiodes. Although the conversion rate varies depending on the light sources (fluorescent light, incandescent light or direct sunlight), in general for a fluorescent light, the light-to-current conversion is: 61μA I OUT = ⎛ ------------------------⎞ × L INPUT ⎝ 1000Lux⎠ (EQ. 1) Here, IOUT is the output current in µA, and LINPUT is the input light in lux. 4 Although the device saturates at 10,000 lux (IOUT = 600µA), the output current must never exceed 6mA. The voltage output compliance of the device is 300mV below the supply. The output current stops ramping when the output voltage reaches voltage compliance. FN6117.6 September 2, 2008 ISL29000 TABLE 1. VDD = 5V, MAXIMUM OUTPUT VOLTAGE = 4.7V Next, the value of R2 can be calculated based on the maximum output current coming from the ISL29000 under the application's maximum light exposure. Suppose the current has been determined to be about 125µA. Thus, R2 can be calculated approximately using Equations 5 and 6: ILLUMINATION RANGE (LUX) RLOAD (kΩ) CURRENT OUT (µA) 0 to 10 7830 0 to 0.6 0 to 200 392 0 to 12 0 to 500 157 0 to 30 0 to 1,000 80 0 to 60 and 0 to 10,000 8.00 0 to 600 R 1 = 11 × R 2 = 110kΩ Application Examples The following examples present from fully automatic to fully manual override implementations. These guidelines are applicable to a wide variety of potential light control applications. The ISL29000 can be used to control the brightness input of CCFL inverters. Likewise it can interface well with LED drivers. In each specific application, it is important to recognize the target environment and its ambient light conditions. The mechanical mounting of the sensor, light aperture hole size and use of a light pipe or bezel are critical in determining the response of the ISL29000 for a given exposure of light. The example in Figure 9 shows a fully automatic dimming solution with no user interaction. Choose R1 and R2 values for any desired minimum brightness and slope. Choose C1 to adjust response time and to filter 50/60Hz room lighting. For example, suppose you wish to generate an output voltage from 0.25V to 1.25V to drive the input of an LED driver controller. The 0.25V represents the minimum LED brightness and 1.25V represents the maximum. The 1st step would be to determine the ratio of R1 and R2: 3.0V R 1 = R 2 × ⎛ ---------------- – 1⎞ = 11 × R 2 ⎝ 0.25V ⎠ 3V TO 5V SUPPLY VOLTAGE (EQ. 4) 1.25V R 2 = ⎛ ------------------⎞ = 10kΩ ⎝ 125μA⎠ (EQ. 5) (EQ. 6) In Figure 10, user adjustable bias control has been added to allow control over the minimum and maximum output voltage. This allows the user to adjust the output brightness to personal preference over a limit range via the 3V PWM control. 3V TO 5V SUPPLY VOLTAGE 3V PWM CONTROL VDO R2 110k ISL29000 EN TO INVERTER BRIGHTNESS INPUT OR LED DRIVER CONTROLLER OUT R1 10k GND C1 25µF FIGURE 10. AUTOMATIC DIMMING SOLUTION WITH ADJUSTABLE BIAS CONTROL Figure 11 shows how a fully manual override can be quickly added by using the EN pin. 3V TO 5V SUPPLY VOLTAGE 3V DC VOLTAGE 3V PWM CONTROL VDO VDO R2 110k ISL29000 EN TO INVERTER BRIGHTNESS INPUT OR LED DRIVER CONTROLLER OUT GND R1 10k ENABLE/ DISABLE CONTROL R2 110k TO INVERTER BRIGHTNESS INPUT OR LED DRIVER CONTROLLER ISL29000 EN OUT C1 25µF GND R1 10k C1 25µF FIGURE 9. AUTOMATIC DIMMING SOLUTION FIGURE 11. AUTOMATIC DIMMING SOLUTION WITH ADJUSTABLE BIAS CONTROL AND MANUAL OVERRIDE 5 FN6117.6 September 2, 2008 ISL29000 Short Circuit Current Limit The ISL29000 does not limit the output short circuit current. If the output is directly shorted to the ground continuously, the output current could easily increase for a strong input light such that the device may be damaged. Maximum reliability is maintained if the output continuous current never exceeds 6mA by adding a load resistor at the output. This limit is set by the design of the internal metal interconnects. Suggested PCB Footprint Footprint pads should be a nominal 1-to-1 correspondence with package pads. The large, exposed central die-mounting paddle in the center of the package requires neither thermal nor electrical connections to PCB, and such connections should be avoided. Power Supply Bypassing and Printed Circuit Board Layout The ISL29000 is relatively insensitive to the printed circuit board layout due to its low speed operation. Nevertheless, good printed circuit board layout is necessary for optimum performance. Ground plane construction is highly recommended, lead length should be as short as possible and the power supply pins must be well bypassed to reduce the risk of oscillation. For normal single supply operation, where the GND pin is connected to ground, a 0.1µF ceramic capacitor should be placed from VCC pin to GND pin. A 4.7µF tantalum capacitor should then be connected in parallel, placed close to the device. All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 6 FN6117.6 September 2, 2008 ISL29000 Package Outline Drawing L5.2x2.1 5 LEAD OPTICAL DUAL FLAT NO-LEAD PLASTIC PACKAGE Rev 1, 05/08 2.10 6 PIN #1 INDEX AREA A B 6 PIN 1 INDEX AREA 1 5 1 2.00 1.35 1.30 REF 2 0.65 0.30±0.05 4 (4X) 3 0.10 0.65 0.10 M C A B 5X 0 . 35 ± 0 . 05 TOP VIEW BOTTOM VIEW (0.65) SEE DETAIL "X" 0.10 C 0 . 7 ± 0 . 05 C ( 5X 0 . 30 ) (0.65) BASE PLANE (1.35) SEATING PLANE 0.08 C SIDE VIEW ( 5X 0 . 55 ) C 0 . 2 REF 5 (1.95) 0 . 00 MIN. 0 . 05 MAX. DETAIL "X" TYPICAL RECOMMENDED LAND PATTERN NOTES: 1. Dimensions are in millimeters. Dimensions in ( ) for Reference Only. 2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994. 3. Unless otherwise specified, tolerance : Decimal ± 0.05 4. Dimension b applies to the metallized terminal and is measured between 0.15mm and 0.30mm from the terminal tip. 5. Tiebar shown (if present) is a non-functional feature. 6. 7 The configuration of the pin #1 identifier is optional, but must be located within the zone indicated. The pin #1 identifier may be either a mold or mark feature. FN6117.6 September 2, 2008