TCS3471 Datasheet, PDF (2/22 Pages) TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS – COLOR LIGHT-TO-DIGITAL CONVERTER

TCS3471
COLOR LIGHT-TO-DIGITAL CONVERTER
TAOS115 − MARCH 2011
Functional Block Diagram
V_DD
GND
Wait Control
Interrupt
INT
RGBC Control
Upper Limit
SCL
Clear
Red
Clear ADC Clear Data
Red ADC Red Data
Lower Limit
Green ADC Green Data
Green
SDA
Blue ADC Blue Data
Blue
Detailed Description
The TCS3471 light-to-digital device contains a 4 × 4 photodiode array, integrating amplifiers, ADCs,
accumulators, clocks, buffers, comparators, a state machine, and an I²C interface. The 4 × 4 photodiode array
is composed of red-filtered, green-filtered, blue-filtered, and clear photodiodes — four of each type. Four
integrating ADCs simultaneously convert the amplified photodiode currents to a digital value providing up to 16
bits of resolution. Upon completion of the conversion cycle, the conversion result is transferred to the data
registers. The transfers are double-buffered to ensure that the integrity of the data is maintained.
Communication to the device is accomplished through a fast (up to 400 kHz), two-wire I²C serial bus for easy
connection to a microcontroller or embedded controller.
The TCS3471 provides a separate pin for level-style interrupts. When interrupts are enabled and a pre-set value
is exceeded, the interrupt pin is asserted and remains asserted until cleared by the controlling firmware. The
interrupt feature simplifies and improves system efficiency by eliminating the need to poll a sensor for a light
intensity value. An interrupt is generated when the value of an RGBC conversion exceeds either an upper or
lower threshold. In addition, a programmable interrupt persistence feature allows the user to determine how
many consecutive exceeded thresholds are necessary to trigger an interrupt.
Terminal Functions
TERMINAL
NAME NO.
GND
3
INT
5
NC
4
SCL
2
SDA
6
V_DD
1
TYPE
DESCRIPTION
Power supply ground. All voltages are referenced to GND.
O
Interrupt — open drain.
Do not connect
I
I²C serial clock input terminal — clock signal for I²C serial data.
I/O
I²C serial data I/O terminal — serial data I/O for I²C .
Supply voltage.
Copyright E 2011, TAOS Inc.
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www.taosinc.com
The LUMENOLOGY r Company
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