LX1973
TM
廬
Automotive Light Sensor
P
RODUCTION
D
ATA
S
HEET
DESCRIPTION
KEY FEATURES
Human Eye Spectral Response
25C Dark Current < 0.005 lux
5 Decades Compressed Output
10% Accuracy Over
Temperature
Scalable Output Voltage
No Optical Filters Needed
The LX1973 is a wide dynamic
range light sensor with a very low
dark current that is optimized for
sensing low level light signals that
typically occur under dark or
darkening outdoor ambient lighting.
The LX1973 has been optimized for
automotive systems such as headlamp
brightness control or rear view mirror
contrast control. Its radical (fractional
exponent) response when interfaced
with an 8 bit DAC can detect levels
down to 0.001 lux or levels as high as
500 lux.
The spectral response of the
integrated light sensor closely
emulates the human eye so it ignores
light such as infrared which emits
energy but doesn鈥檛 aid vision. This
eliminates the need for an Infrared
filter required with competitor鈥檚 light
sensors.
The LX1973 internal circuitry
consists of a diode array that provides a
nearly perfect photopic light wave-
length response curve. The sensor
output feeds into a wide dynamic range
compression amplifier that provides
accurate resolution over five decades of
ambient light. The integrated dark
current cancellation circuit facilitates
accurate sensing of light below 0.01
lux. The current source output of the
LX1973 can be gain scaled using one
external resistor.
The LX1973 is internally trimmed to
an initial accuracy of 5% at room
temperature and a light level of 10lux.
Accuracy of 10% is maintained over the
full temperature range (-40 to +85C).
WWW .
Microsemi
.C
OM
APPLICATIONS
Auto Headlamp Control
Auto Mirror Contrast Control
IMPORTANT:
For the most current data, consult
MICROSEMI鈥檚
website:
http://www.microsemi.com
Protected by US Patent: 6,787,757; Patents Pending
PRODUCT HIGHLIGHT
LX1973 Response
5V
Output (in Volts)
4.0000
3.0000
2.0000
1.0000
0.0000
0.001
NC
LX1973
Part
V
OUT
10k
0.01
0.1
1
10
100
Ambient Light (in lux)
LX1973
LX1973
PACKAGE ORDER INFO
T
A
(擄C)
-40 to 85
DU
Plastic MSOP
8-pin
RoHS Compliant / Pb-free
LX1973IDU
Note: Available in Tape & Reel. Append the letters 鈥淭R鈥?to the
part number. (i.e. LX1973IDU-TR)
Copyright
漏
2004
Rev. 1.0 2006-01-04
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
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