TCS230

PROGRAMMABLE

COLOR LIGHT-TO-FREQUENCY CONVERTER

TAOS046Q − JULY 2008

1

The LUMENOLOGY

r Company

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Copyright

E 2008, TAOS Inc.

www.taosinc.com

Intensity to Frequency

Frequency

Compliant Surface-Mount Package

Description

The TCS230 programmable color light-to-frequency converter combines configurable silicon photodiodes and

a current-to-frequency converter on a single monolithic CMOS integrated circuit. The output is a square wave

(50% duty cycle) with frequency directly proportional to light intensity (irradiance). The full-scale output

frequency can be scaled by one of three preset values via two control input pins. Digital inputs and digital output

allow direct interface to a microcontroller or other logic circuitry. Output enable (OE) places the output in the

high-impedance state for multiple-unit sharing of a microcontroller input line.

The light-to-frequency converter reads an 8 x 8 array of photodiodes. Sixteen photodiodes have blue filters, 16

photodiodes have green filters, 16 photodiodes have red filters, and 16 photodiodes are clear with no filters.

The four types (colors) of photodiodes are interdigitated to minimize the effect of non-uniformity of incident

irradiance. All 16 photodiodes of the same color are connected in parallel and which type of photodiode the

device uses during operation is pin-selectable. Photodiodes are 120

μm x 120 μm in size and are on 144-μm

centers.

Functional Block Diagram

Light

Current-to-Frequency

Converter

Photodiode

Array

S2

S3

S0

S1

OE

Output

r

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Texas Advanced Optoelectronic Solutions Inc.

1001 Klein Road

S Suite 300 S Plano, TX 75074 S (972) 673-0759

8 S3

7 S2

6 OUT

PACKAGE D

8-LEAD SOIC

(TOP VIEW)

S0 1

S1 2

OE 3

GND 4