24-03-2011, 01:04 PM
Presented by:
M.DINESH REDDY
[attachment=10912]
Photosensors or photodetectors
Photodetectors are classified into following types :
Optical detectors, which are mostly quantum devices in which an individual photon produces a discrete effect
Chemical detectors, such as photographic plates, in which a silver halide molecule is split into an atom of metallic silver and a halogen atom. The photographic developer causes adjacent molecules to split similarly
Charge coupled devices(CCD), which are used to record images in astronomy,Digital photography, and digital cinematography.
The ISL29001 is an integrated ambient light sensor with ADC interface
the ISL29001 provides 15-bit effective resolution while rejecting 50Hz and 60Hz flicker caused by artificial light sources
The ISL29001 includes an internal oscillator, which provides 100ms automatic integration periods, designed to operate on supplies from 2.5V to 3.3V
The ISL29001 is specified for operation over the -40°C to +85°C ambient temperature range
Features
Human eye response
Temperature compensated
IR rejection
15-bit effective resolution
2.5V to 3.3V supply
50Hz/60Hz rejection
Principle of Operation
ISL29001 contains two photodiodes
[ Diode 1 ]photodiodes is sensitive to visible and infrared light diode.
[Diode 2] is used for temperature compensation (leakage current cancellation) and IR rejection.
ISL29001 contains an on-chip integrating analog-to-digital converter (ADC) to convert photodiode currents into digital data.
OPERATION MODES
The ADC has three operating modes with two timing controls:
MODE 1
the ADC only integrates Diode 1's current, and the digital output format is 16-bit unsigned-magnitude
MODE 2
the ADC's operation is the same, except Diode 2's current is integrated
MODE 3
the ADC integrates Diode 2's current first, then Diode 1's current. The total integration time is doubled.
APPLICATONS
Ambient light sensing
Ambient backlight control
Temperature control systems
Contrast control
Camera light meters
Lighting controls
HVAC
M.DINESH REDDY
[attachment=10912]
Photosensors or photodetectors
Photodetectors are classified into following types :
Optical detectors, which are mostly quantum devices in which an individual photon produces a discrete effect
Chemical detectors, such as photographic plates, in which a silver halide molecule is split into an atom of metallic silver and a halogen atom. The photographic developer causes adjacent molecules to split similarly
Charge coupled devices(CCD), which are used to record images in astronomy,Digital photography, and digital cinematography.
The ISL29001 is an integrated ambient light sensor with ADC interface
the ISL29001 provides 15-bit effective resolution while rejecting 50Hz and 60Hz flicker caused by artificial light sources
The ISL29001 includes an internal oscillator, which provides 100ms automatic integration periods, designed to operate on supplies from 2.5V to 3.3V
The ISL29001 is specified for operation over the -40°C to +85°C ambient temperature range
Features
Human eye response
Temperature compensated
IR rejection
15-bit effective resolution
2.5V to 3.3V supply
50Hz/60Hz rejection
Principle of Operation
ISL29001 contains two photodiodes
[ Diode 1 ]photodiodes is sensitive to visible and infrared light diode.
[Diode 2] is used for temperature compensation (leakage current cancellation) and IR rejection.
ISL29001 contains an on-chip integrating analog-to-digital converter (ADC) to convert photodiode currents into digital data.
OPERATION MODES
The ADC has three operating modes with two timing controls:
MODE 1
the ADC only integrates Diode 1's current, and the digital output format is 16-bit unsigned-magnitude
MODE 2
the ADC's operation is the same, except Diode 2's current is integrated
MODE 3
the ADC integrates Diode 2's current first, then Diode 1's current. The total integration time is doubled.
APPLICATONS
Ambient light sensing
Ambient backlight control
Temperature control systems
Contrast control
Camera light meters
Lighting controls
HVAC