feature

8226 ; Excellent responsivity, peaking in the human photometric curve Near response to the human eye

• Microchip lead-free surface mount components: Height – 0.80 mm; Width – 2.00 mm; Depth – 1.25 mm

• Good output linear illumination range over a wide range

• Low sensitivity to varying light sources

• Guaranteed temperature performance -40°C to 85°C

• VCC supply 2.4 to 5.5 V

• Lead-free packaging

application

• Detects ambient light to control display backlighting; mobile devices - mobile phones, PDA systems; computing devices - laptops, web pages; consumer devices - TVs, camcorders, digital cameras

• Automatic residential and commercial lighting management

• Electronic signs and signals

• Daylight and artificial light exposure devices

illustrate

The APDS-9002 is a low cost analog output ambient light sensor in the lowest cost microchip LED lead-free surface mount package. It consists of a spectrally matched phototransistor that peaks in the human luminosity curve. Therefore, it provides a response close to that of the human eye, as shown in Figure 2. It provides an alternative design of the HSDL-9000 digital output ambient light sensor suitable for ultra-small portable application packaging design.

APDS-9002 is suitable for measurement of ambient light for controlling display backlight. Mobile devices such as cell phones and PDAs because of display backlighting will benefit from incorporating these photo sensor product designs significantly by reducing power consumption.

Application Support Information

The Application Engineering Group can assist you with the application design related to the APDS-9002 Ambient Light Sensor Module. You can contact them through your local sales representative for more details.

Ordering Information

Typical Application Circuit

I/O Pin Configuration Table

CAUTION: General electrostatic precautions are recommended when handling and assembling this part to prevent damage and/or degradation from ESD.

Absolute Maximum Ratings

For devices with ambient thermal resistance less than or equal to 50°C/W

Recommended Operating Conditions

Electrical and Optical Specifications (TA=25°C)

notes:

1. The illuminance of CIE standard light source (incandescent lamp).

2. Fluorescent lamps are used as light sources. In mass production, white LEDs were replaced.

3. Use white LED as light source.

Optical measurement circuit and waveform

APDS-9002 Packaging Outline

APDS-9002 Tape and Reel Dimensions

Moisture-proof packaging

All APDS-9002 options are packaged in a moisture-proof package. After opening, it starts to absorb moisture.

This part complies with JEDEC Level 4.

Baking conditions

If the part is not stored in dry conditions, it must be baked before reflow to prevent damage to the part.

Baking can only be done once.

Time from opening to welding after removal from bag, parts should be welded within three days if stored under recommended storage conditions. If more than three days are required, parts must be stored in a dry box.

Recommended reflow profile

The reflow profile is a straight line representation of the nominal temperature profile of the convection reflow process. The temperature distribution is divided into four process zones, and the DT/Dtime temperature change rate of each process zone is different. The table above details the DT/DT time rate. The temperature is measured at the connection of the component to the printed circuit board.

In process zone P1, the PC board and APDS-9002 honeycomb pins are heated to 160°C to activate the flux in the solder paste. The temperature rise rate R1 is limited to 4°C per second in order to be able to uniformly heat the PC board and APDS-9002 honeycomb.

Process zone P2 should have sufficient time (60 to 120 seconds) to dry the solder paste. The temperature is raised to a level just below the liquidus point of the solder, typically 200°C (392°F).

Process area P3 is a solder reflow area. In zone P3, the temperature is rapidly increased to 255°C (491°F) above the liquidus point of the solder for best results. The dwell time above the solder liquidus should be between 20 and 60 seconds. It usually takes about 20 seconds to ensure that the solder balls bond properly with the liquid solder and make a good solder joint connection. After dwell times of more than 60 seconds, the intermetallics within the solder connections overgrow, resulting in weak and unreliable connections. The temperature is then rapidly reduced below the solid state temperature of the solder, typically 200°C (392°F), to freeze the solder in the solid state within the connector.

Process zone P4 is the cooling after the solder freezes. The cooling rate R5 from the solder liquidus point to 25°C (77°F) shall not exceed a maximum of 6°C per second. This restriction is necessary to allow the PC board and APDS-9002 honeycomb to change size on average to minimize stress on the APDS-9002.

Appendix A: SMT Component Application Note Agilent APDS-9002: Miniature Surface Mount Ambient Light Sensor

1.2 Recommended Metal Solder Stencil Holes

A 0.10 mm (0.004 in) thick stencil is recommended for solder paste printing. The aperture of the shielding pad is 0.6 mm x 0.6 mm. This is to ensure sufficient volume of printed solder paste and no shorts.

1.3 Adjacent solder forbidden area and solder mask area

Adjacent land blockout refers to the maximum space occupied by a unit relative to the land pattern. There should be no other SMD components in this area.

The minimum solder mask tape width required to avoid solder bridging adjacent pads is 0.2mm.

NOTE: Wet/liquid photoimageable solder mask/mask is recommended.

2.0 Optical window size

To ensure that the performance of the APDS-9002 is not affected by an inappropriate window design, there are some restrictions on the size and design of the window. There is a limit to the minimum size of the window, which is located on the photosensor so that it does not affect the angular response of the APDS-9002. The recommended minimum size will ensure at least a ±35° light receiving cone.

If smaller windows are required, light tubes or light guides can be used. A light pipe or light guide is a cylindrical piece of clear plastic that uses total internal reflection to focus light.

The thickness of the windows should be kept as minimal as possible, as the power loss per optical window is about 8% due to reflections (4% per side) and additional energy losses in the plastic material.

Figures 12(a) and 12(b) illustrate the two types of windows we recommend, which can be either flat or flat with light guides.

Table 1 below and Figure 13 show the recommended size of the window. These dimension values are based on a 1.0 mm window thickness with an index of refraction of 1.585.

The window should be placed directly on top of the light sensor for better performance, if a window with a light tube is used, the dimension D2 should be 1.5mm to optimize the performance of the APDS-9002.

2.1 Optical window materials

The material of the windows is polycarbonate recommended. The surface finish of the plastic should be smooth without any texture.

The recommended plastic materials can be used as windows Bayer AG and Bayer Antwerp N, V. (Europe), Bayer AG (USA) Bayer Polymer Materials GmbH. (Thailand), as shown in Table 2.

Appendix C: APDS-9002 General Application Guidelines

The APDS-9002 is a low-cost analog output ambient light sensor with a spectral response very similar to that of the human eye. The APDS-9002 consists of a phototransistor that enables the photosensor to generate a sufficient high-gain photocurrent that can be converted to a voltage with the standard value of an external resistor. The APDS-9002 is then easily integrated into a system using an ADC input (which can be used for sampling from an external source), as shown in Figure 14 below.

The amount of conversion voltage, VOUT, depends primarily on the photocurrent generated by the brightness of the light shining on the light sensor and the load resistor RL used. Increasing lamp brightness and/or load resistance will increase the output voltage.

Brightness is measured in "lux" units, which describe the intensity of a light source as perceived by our eyes. A luxmeter is an instrument that measures lux. Light sources with the same lux level show the same brightness to the human eye.

The choice of load resistor RL will determine the amount of current-voltage conversion in the circuit. Based on Figure 14, using a white LED as the light source, measurements were made with different load resistances to examine the output voltage versus lux intensity. The results are shown in Figure 1. The APDS-9002 allows the output voltage to reach around 2.3V, after which it saturates.

Light sources, such as fluorescent lamps, consist of AC noise at frequencies around 100 Hz. A 10µF capacitor is recommended as a low pass filter in parallel with the resistor to bypass the ripple.

Agilent built an evaluation board based on the configuration shown in Figure 14 for designers to test ambient light sensors under different lighting conditions. The reference layout of the 2-layout Agilent evaluation board for the APDS-9002 is shown in Figure 15 below.

/semiconductor

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