TSL238

HIGH-SENSITIVITY

LIGHT-TO-FREQUENCY CONVERTER

TAOS073J − SEPTEMBER 2008

5

The LUMENOLOGY

r Company

r

r

Copyright

E 2008, TAOS Inc.

www.taosinc.com

TYPICAL CHARACTERISTICS

Figure 5

NORMALIZED OUTPUT FREQUENCY

vs.

ANGULAR DISPLACEMENT

Q − Angular Displacement − °

0

0.2

0.4

0.6

0.8

1

−90

−60

−30

0

30

60

90

Angular Displacement is

Equal for Both Aspects

Figure 6

DARK FREQUENCY

vs.

FREE-AIR TEMPERATURE

−7.5

−4.5

−1.5

1.5

4.5

7.5

−25

−5

15

35

55

75

−6.0

−3.0

0.0

3.0

6.0

NOTE A

NOTE A: Internal offsets that result in dark frequency can be both positive and negative. The dashed line represents the case of negative offset

in which an equivalent amount of light signal is required to obtain a non-zero output frequency.

Figure 7

λ − Wavelength of Incident Light − nm

PHOTODIODE RESPONSIVITY TEMPERATURE

COEFFICIENT

vs.

WAVELENGTH OF INCIDENT LIGHT

1k

2k

3k

4k

5k

6k

7k

8k

9k

10k

0

11k

600

650

700

750

800

850

900

950

1000