TSL2550-RS232EVM TAOS, TSL2550-RS232EVM Datasheet - Page 7

• Manufacturer Part Number: TSL2550-RS232EVM
• Description: Optical Sensor Development Tools Evaluation Module TSL2550
• Manufacturer: TAOS

Specifications of TSL2550-RS232EVM

• Maximum Operating Temperature: + 55 C
• Minimum Operating Temperature: 0 C
• Description/function: Ambient Light Sensor
• For Use With/related Products: TSL2550
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The Count Value for each channel is obtained by the following equation:
Illuminance (i.e. ambient light brightness) is derived using the values read from Channel 0 and
Channel 1 in the units of Lux to approximate the human eye response. The formula follows:
The coefficients of the equation can be modified from the ‘Settings/Lux Formula’ pull down menu
item. See Figure 4.
C
As shown on Figure 3, a relative indication of the color temperature of the light source can be made
for the purpose of light source classification. Color temperature can be estimated by taking the ratio
of infrared light to the combination of visible and infrared light (i.e. Ch1/Ch0). Fluorescent lighting,
for example, represents almost all visible light. Incandescent lighting, on the other hand, represents a
combination of visible and infrared light (i.e. about half-visible and half-infrared).
From Figure 3, the correlated color temperature of the ambient light source is roughly proportional to
Ch0/Ch1 (i.e. the inverse of the ratio described in Table 3). This information may be useful in certain
applications such as computer displays and television screens to perform color balance.
Count Value = Chord Value + (Step Number x Step Value)
Count Value = (INT (16.5 x (2
Light Level (lux) = Ch0 Counts x 0.46 x e
OLOR
Fluorescent
Daylight (shade)
Incandescent
T
Light Source
EMPERATURE
Table 3. TSL2550 Sensor Output Summary
Chord Number
Figure 4. Modify TSL2550 Equation
Lux
300
100
50
– 1)) + (Step Number x 2
-3.13(Ch1 Counts/Ch0 Counts)
Ch0 Counts
7 of 8
831
895
959
Ch1 Counts
Chord Number
343
671
68
)
Ch1/Ch0
0.082
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0.38
0.7
Eq. 1
Eq. 2
Eq. 3