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Q1.What is a reflective photo-interruptor and where is it commonly used in?
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A reflective phtot-interruptor has both the emitter and detctor housed on the same side of the sensor. The emitter send off infrared light which bouces off the object surface to be picked up by the detector. Typically reflective photo-interruptors are used in industrial applications and productions lines as counters. Increasingly small SMD reflective sensors are used in mobile devices as proximity sensors.
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Q2.Difference between analog and digital ambient light sensor ?
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(1) Analog :
- Additional signal processing circuitries required including a dedicated ADC
- Small dynamic range, typically up to 1k lux as photodiode current will saturate under outdoor application
- Poor linearity for photo-transistors type of sensors
- No shutdown mode
(2) Digital :
- No additional signal processing circuitries required. Device includes I-V conversion / amplification / 50/60Hz rejection / temperature compensation circuitries.
- Smaller PCB space / Lower total cost
- No dedicated interface circuit required. Interface is via I2C bus and the microcontroller can connect up to 255 slave devices in parallel.
- Wide dynamic range up to 65k lux / 100k lux which is suited for both indoor and outdoor applications
- Shutdown mode / Interrupt / Persist feature
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Q3.What is an Encoder?
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An encoder is a device that converts information from one format to another. Liteon's encoder typically converts the number of revolution of a code wheel or the distance moved by a code strip to a digital count.
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Q4.Is Proximity Sensor are necessary discrete solutions ?
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No, Liteon offers integrated Digital Ambient Light Sensor and Proximity Sensor, which offers advantages such as small form factor, better accuracy and resolution.
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Q5.Is IrDA restricted by RF (radio frequency) regulations ?
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IrDA is using infrared technology. Not affected by RF regulations.
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Q6.What sre the kep types of photo-interruptors?
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The key types of photo-interruptors includes actuator, slot and reflective.
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Q7.Does Liteon provide both aalog and digital encoders?
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Currently Liteon only have digital encoders in our portfolio. However, Liteon does have the capability of producing analog encoders if there is sufficient customer demand.
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Q8.What is the Ambient Light Sensor ?
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Ambient Light Sensor are used to measure the surrounding lighting conditions, as perceived by the Human Eye.
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Q9.What are the key applications that Liteon encoders are used in?
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Liteon encoders are used in a wide range of applications. It is most widely used in printers for functions like, paper feed and ink head positioning.
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Q10.Is IrDA restricted by RF (radio frequency) regulations ?
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IrDA is using infrared technology. Not affected by RF regulations.
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Q11.What is a photo-interruptor?
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A photo-interruptor is a sensor that uses light path to detect the prescence of an object and gives a signal output when an object is detected. Typically in has an emmitter and detector put together in a housing.
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Q12.What is a slot photo-interruptor and where is it commonly used in?
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A slot photo-interruptor normally has a U-shape housing with the emitter and detector at opposite ends of the U shape tip, thus creating a slot between the emitter and detector. The object of detection normal pass through the slot and thus blocking the light path triggering a detection out put. Slotted photo-interruptors are used in applications where the object is small enough to pass through the slot. Generally slot photo-interruptors are used in applications like printers as paper detectionsensor and cover sensor.
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Q13.What are the key parameters/features in choosing digital encoders?
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When choosing the a digital encoders, the first parameter to determine is the resolution needed. Typically this is in lines per inch (lpi). After whichthe package size will be the most common fearture that customer looked at.
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Q14.What are the various used model (application) for ambient light sensor ?
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(1) Improve Viewing Experience : Automatically control the brightness of the display under bright / dim conditions.
(2) Increase battery life : Dimming the display when it is appropriate, reduce power consumption.
(3) Automatic Keyboard Illumination : Automatically illuminating key pad/ board in dark lighting conditions.
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Q15.Difference between Linear and Logarithmic Digital Light Sensor ?
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(1) Linear
- Full dynamic range up to 65 klux.
- 16-bit ADC: Requires two bytes reading.
- 16-bit ADC: 1 lux/1 count, higher resolution.
(2) Logarithmic
- Human eye has a logarithmic response to ambient light level.
- Full dynamic range up to 100 klux.
- 6-bit ADC: Requires one byte reading only.
- Simple Interrupt / Persist operation, less software intensive or fewer I2C communication.
- 6-bit ADC: lower resolution.
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Q16.What is an actuator photo-interruptor and where is it commonly used in?
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An actuator interruptor has an external arm in which the object of detection comes into contact with. The arm when contacted will move to block the light path between the emitter and detector, triggering a detection output. Actuator photo-interruptors are commonly used in slot and coin machines.
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Q17.What is the difference between analog and digital encoders?
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Analog encoders provide a linear direct output whereas digital encoders noprmally provide a step coun function and thus encompasses an AD converter.
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Q18.Key difference between the Liteon LTR-502ALS-01 and LTR-505ALS-01 ?
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(1) LTR-502ALS
- Digital Light Sensor + Proximity Sensor with LED driver.
- Proximity Sensor detection distance, 5cm (typical).
- More flexible and less complex optical window design.
(2) LTR-505ALS
- Digital Light Sensor + Proximity Sensor with LED driver and IR LED.
- Fully integrated solution.
- Proximity Sensor detection distance, 2.5 cm (typical).
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Q19.What is the typical communication distance for the IrDA products ?
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(1) Low Power product : 20-30cm
(2) Standard Power product : 1 meter
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Q20.What is the fastest data rate available for IrDA ?
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16M bits/s : VFIR solution, but in terms of product supportability, 4M bit/s is available in the industry.
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Q21.What is the advantage of using IrDA for data transfer application ?
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(1) It is a wireless technology.
(2) Line of sight - Secure means of transferring data.
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Q22.What is isolation voltage of photo coupler?
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Isolation voltage uses to evaluate isolation capability of photo coupler. It means isolation voltage between input and output of photo coupler.
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Q23.How many safety certification that Liteon photo coupler have?
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UL, CSA, VDE, FIMKO, NEMKO, DEMKO, and SEMKO.
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Q24.How many packages of Liteon photo coupler?
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Q25. What is photo coupler maximum operation temperature?
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Liteon photo coupler maximum operation temperature is 110°C.
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Q26.How is isolation voltage of Liteon photo coupler?
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Photo coupler packages of dip, wide lead, and SMD type are 5000Vrms. Min-flat type and Half-pitch are 3750Vrms.
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Q27.Does Liteon has Halogen free photo coupler?
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Liteon has total solution of Halogen free products and Liteon is the first one to product Halogen free photo coupler.
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Q28.What is photo moisture sensitivity level (MSL)?
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Follow JEDEC J-STD-020C moisture sensitivity level (MSL ) of Liteon photo coupler is Level 1.
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Q29.What is CTR rank of photo coupler?
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RANK MARK
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CTR ( % )
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L
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50 ~ 100
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A
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80 ~ 160
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B
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130 ~ 260
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C
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200 ~ 400
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D
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300 ~ 600
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L or A or B or C or D
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50 ~ 600
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For special CTR rank can contact with Liteon.
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Q30.What is CTR of photo coupler?
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CTR is current transfer ratio, it can be defined CTR= IC/IF.
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Q31.SMD LED Category?
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(1) PCB Substrate, call Chip LED.
(2) Lead - Frame Substrate, call PLCC.
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Q32.What is soldering condition of LED Lamp?
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Soldering iron and wave soldering is only one time.
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Soldering iron
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Wave soldering
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Temperature
Soldering time
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300°C Max.
3 sec. Max.
(one time only)
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Pre-heat
Pre-heat time
Solder wave
Soldering time
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100°C Max.
60 sec. Max.
260°C Max.
5 sec. Max.
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Q33.How many packages are in Thru – Hole LED LAMPS?
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Major packages are 3mm lamp, 5mm lamp, Oval lamp, Piranha lamp and CBI.
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Q34.How many packing types are in LITEON LED lamp?
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Liteon has loose packing and ammo packing (Tape and reel)
(1) Loose pack: 250, 500, 1000 units/bag.
(2) Ammo pack: 2000pcs/ box.
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Q35.How much operation current is for LITEON LED lamp?
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Indicator lamp:
|
Lamp LED
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Operation current
|
Chip
|
|
White
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5~20mA
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InGaN
|
|
Blue
|
5~20mA
|
InGaN
|
|
Cyan
|
5~20nm
|
InGaN
|
|
Green
|
5~20nm
|
InGaN
|
|
Yellow Green
|
2~20nm
|
GaP / GaAsP
|
|
Yellow
|
2~20nm
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GaP / GaAsP
|
|
Amber
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2~20nm
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GaP / GaAsP
|
|
Orange
|
2~20nm
|
GaP / GaAsP
|
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Red
|
2~20nm
|
AlGaInP / GaP / GaAsP / AlGaAs
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High brightness lamp
|
Lamp LED
|
Operation current
|
Chip
|
|
White
|
20~30mA
|
InGaN
|
|
Blue
|
20~30mA
|
InGaN
|
|
Cyan
|
20~30nm
|
InGaN
|
|
Green
|
20~30nm
|
InGaN
|
|
Yellow Green
|
20~30nm
|
AlGaInP
|
|
Yellow
|
20~50nm
|
AlGaInP
|
|
Amber
|
20~50nm
|
AlGaInP
|
|
Orange
|
20~50nm
|
AlGaInP
|
|
Red
|
20~50mA
|
AlGaInP
|
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Q36.How to check view angle in LED lamp?
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Circuit model A: One lamp connects one resistor. Brightness can be uniform.
(1) 3mm & 5mm lamps are normal lens, so view angle will be uniform in any direction.
(2) Oval lamp is ellipse lens, so view angle is different in X-Y axis.
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Q37.What is LED?
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A lighting emitting diode (LED) is a semiconductor device that emits incoherent narrow spectrum light when electrically biased in the forward direction of p-n junction. The color of the emitted light depends on the composition and condition of the semiconducting material used, and can be infrared, visible, or near-ultraviolt.
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Q38.What is the Luminous intensity?
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Unit : candela, intensity is the ratio of flux by solid angle.
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Q39.How many colors can Thru-Hole LED LAMPS of LITEON support?
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Color
|
Wavelength
|
Chip
|
|
White
|
X: 0.31~0.41
Y: 0.32~0.39
|
InGaN
|
|
Blue
|
460~475nm
|
InGaN
|
|
Cyan
|
500~510nm
|
InGaN
|
|
Green
|
520~535nm
|
InGaN
|
|
Yellow Green
|
565~575nm
|
AlGaInP / GaP / GaAsP
|
|
Yellow
|
584~594nm
|
AlGaInP / GaP / GaAsP
|
|
Amber
|
600~610nm
|
AlGaInP / GaP / GaAsP
|
|
Orange
|
610~620nm
|
AlGaInP / GaP / GaAsP
|
|
Red
|
620~660nm
|
AlGaInP / GaP / GaAsP / AlGaAs
|
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Q40.What is the Luminous Flux?
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Unit : lumen, Luminous Flux is a measure of the power of visible light. Photopic flux, express in lumens, is weighted to match the responsivity of human eyes.
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Q41.Product Meet Rohs, Halogen Free, and Pb Free?
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The whole Liteon LED Product already pass Rohs, Pb-free and Rohs, and then we provide Halogen Free product to customers, too.
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Q42.What is SMD LED?
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SMD LED - surface- mount device LED.
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Q43.How to use LITEON LED Lamp in circuit design?
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(1) Circuit model A: One lamp connects one resistor. Brightness can be uniform.
(2) Circuit molde B: Two or more lamps connect one resistor. Brightness will be a little different due to I-V characteristics.
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Q44.How to select LED Lamp in Liteon Data sheet?
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In LITEON Data sheet, we will show IV, Hue, Vf, and view angle. Users can select the suitable spec. from LITEON’s LED lamp.
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Q45.Can LITEON LED LAMP be passed with IR-reflow process?
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IR-reflow is for SMD type LED. Normal lamp LED is thro-hole type, so it can’t be passed with IR-reflow process.
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