TSL2562, TSL2563

LOW-VOLTAGE

LIGHT-TO-DIGITAL CONVERTER

TAOS066J − MAY 2007

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Copyright E 2007, TAOS Inc.

The LUMENOLOGY r Company

www.taosinc.com

Functional Block Diagram

Two-Wire Serial Interface

Address Select

Interrupt

SDA

Channel 0

Visible and IR

Channel 1

IR Only

Command

Register

ADC

Register

INT

SCL

ADDR SEL

Integrating

A/D Converter

Detailed Description

The TSL2562 and TSL2563 are second-generation ambient light sensor devices. Each contains two integrating

analog-to-digital converters (ADC) that integrate currents from two photodiodes. Integration of both channels

occurs simultaneously. Upon completion of the conversion cycle, the conversion result is transferred to the

Channel 0 and Channel 1 data registers, respectively. The transfers are double-buffered to ensure that the

integrity of the data is maintained. After the transfer, the device automatically begins the next integration cycle.

Consequently, the TSL256x device can be easily connected to a microcontroller or embedded controller. No

external circuitry is required for signal conditioning, thereby saving PCB real estate as well. Since the output

of the TSL256x device is digital, the output is effectively immune to noise when compared to an analog signal.

The TSL256x devices also support an interrupt feature that simplifies and improves system efficiency by

eliminating the need to poll a sensor for a light intensity value. The primary purpose of the interrupt function is

to detect a meaningful change in light intensity. The concept of a meaningful change can be defined by the user

both in terms of light intensity and time, or persistence, of that change in intensity. The TSL256x devices have

the ability to define a threshold above and below the current light level. An interrupt is generated when the value

of a conversion exceeds either of these limits.