ALS-PDIC17-57B-TR8 Datasheet, PDF (11/19 Pages) Everlight Electronics Co., Ltd – Surface - Mount I2C Digital Ambient Light Sensor

Surface - Mount
I²C Digital Ambient Light Sensor
ALS-PDIC17-57B/TR8
Theory of Operation
The photocurrent, generated by the built-in photodiode while being illuminated, is
proportionally converted to frequency; the digital frequency signal is then integrated by a
15-bit counter for a predetermined period of time (t_int). This period of time is called integration
time. The converted data are read out through a two-wire, I²C Interface bus. Since the
photodiode has been specially processed to suppress the spectral response in infrared region,
the readout is very close to the photonic transfer function, V(λ), which is the mathematic
expression of human-eye's response to ambient light.
Address Option for I²C
The I²C address is determined before placing an order; the default address is 0x29.
ADC Register
The ADC register contains 16 bits with a 15-bit wide data from D0 to D14 and a valid bit
D15. The register is divided into two groups; D[15..8] is the most significant (MS) byte and
D[7..0] is the least significant (LS) byte. See Table 1 for details.
Table 1 ADC Register Structure
Valid Bit Data Bits
D15
D14 D13 ~ D8
MSB
Most Significant (MS) byte
D7~D1
D0
LSB
Least Significant (LS) byte
Everlight Electronics Co., Ltd.
Document No: DLS-00000xx Rev0.1
11
http://www.everlight.com
Jun. 22, 2011