TSL238

HIGH-SENSITIVITY

LIGHT-TO-FREQUENCY CONVERTER

TAOS073J − SEPTEMBER 2008

3

The LUMENOLOGY

r Company

r

r

Copyright

E 2008, TAOS Inc.

www.taosinc.com

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

High-level output voltage

4

4.5

V

Low-level output voltage

0.25

0.4

V

High-level input current

−10

10

μA

Low-level input current

−10

10

μA

Supply current

2

3

mA

Full-scale frequency (Note 2)

500

1000

kHz

Temperature coefficient of responsivity

±200

ppm/

°C

Supply-voltage sensitivity

±0.5

%/ V

NOTES: 1. The input irradiance is supplied with green LED light source with peak wavelength = 524 nm.

2. Full-scale frequency is the maximum frequency of the device without saturation. Higher irradiance will not result in any additional

increase of output frequency. The output frequency will remain at approximately the saturation frequency to a minimum of 1000

μW/sqcm 524-nm irradiance. During production testing, devices are not tested at this very high irradiance level.

3. Measured at wafer probe using 50

°C hot chuck.

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

Output frequency

40

50

60

kHz

f

Dark frequency

0

1.2

Hz

Dark frequency

0

6

Hz

Irradiance responsivity

2.3

kHz/(

μW/

λp

Peak response wavelength

700

nm

Nonlinearity (Note 2)

±1%

%F.S.

Step response to full-scale step input

1 pulse of new

frequency plus 1

μs

Time from OE low to output enabled

1 period of output

frequency

NOTES: 1. Measured at wafer probe using 50

°C hot chuck.

2. Nonlinearity is defined as the deviation from a straight line between zero and maximum of stated range, expressed as a percent

of stated range.