ASR8600 Datasheet, PDF (5/14 Pages) AMIC Technology – Ambient Light, Solar-UV, IR and Proximity Sensor

ASR8600
Function Description
Light Sensor
The ASR8600 converts light intensity of ambient light (ALS),
Infrared light (IR) or Solar-UV to digital signal through I2C
interface by various photodiodes and ADC circuit. The I2C
interface follows Philip^TM I2C specification with an open
drain active Interrupt pin.
The built-in ADC has 12 bits resolution. ASR8600 offers
user flexibility selection in integration time or gain for
different specific light detection range. If the light detection
is in general purpose, the user can use ASC (Auto Scale
Control) mode which can automatically adjust integration
time and gain to the best resolution for various light intensity.
The user has no need manually to set the integration time or
gain. With ASC mode, the output data is in dynamic range
of 16 bits. The Solar-UV sensing adopts only ASC mode
internally without manual mode option.
If the sensor will be under an overlay that is not 100%
transmissive to light source, the light data can be trimmed
back to the correct one. Please contact AMIC for more
information on adjusting these offset.
Proximity Sensor
Proximity sensing uses an external light source (generally
an infrared emitter) to emit light, which is then viewed by the
integrated light detector to measure the amount of reflected
light when an object is in the light path. The amount of light
detected from a reflected surface can then be used to
determine an object’s proximity to the sensor. The spectrum
of external LED/LD light source can be IR or Green selected
by customer using user command.
Reflective Object
Overlay Glass
LED/LD
When the proximity sensing is enabled, the external LED/LD
is driven by the built-in driver through the LDR pin. The
driving current of LED/LD is widely optional with range from
2.5mA to 300mA, and the pulse time is also changeable
from 0.1ms to 12.8ms. These optional settings are according
to the distance to be detected in application.
The ADC resolution of PS sensing is 8 bits with PS Offset
function to cancel the PS optical crosstalk from overlay
reflection. The PS offset value can be measured by PS
function without any object in front of the overlay, and set by
0xA5 user command of PS offset. The ASR8600 PS Offset
function can cancel the system internal reflection but still
keep full dynamic range of 8 bits (256 steps) of PS output,
so that the user is no need to modify the PS threshold
setting when applying PS Offset function.
ASR8600 also offers PS Auto Trim function if user requires
precise proximity distance to be detected in application. The
PS Auto Trim function can automatically set optimized gain
value in chip according to the preset object distance in front
of chip, and the value could be easily read out through user
command once the trim operation is done.
Solar Ultraviolet (Solar_UV) Index
The Solar_UV Index is a number linearly related to the
intensity of sunlight reaching the earth and is weighted
according to the CIE Erythemal Action Spectrum. This
weighting is a standardized measure of human skin's
response to different wavelengths of sunlight from UVB to
UVA. The UV Index has been standardized by the World
Health Organization and includes a simplified consumer UV
exposure level. ASR8600 can sense Solar_UV with 16 bits
output data, and user can divide it by 100 times magnitude
to get Solar_UV index.
CIE action spectrum
1e+00
1e-01
1e-02
Background Light
Optical Crosstalk
PROX
Sensor
1e-03
UV-B
UV-A
1e-04
280
300
320
340
360
380
400
Wavelength (nm)
PRELIMINARY (March, 2015, Version 0.0)
CIE Erythemal Action Spectrum and UV Index Scale
4
AMIC Technology Corp.