Light-to-Digital Converters aid in ambient light sensing.
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Press Release Summary:
Single-chip devices TSL2560 and TSL2561 enable display panel backlighting to be managed automatically. Measuring light levels from 0.1-40,000 lux, both combine visible light blocking photodiode with broadband photodiode on one CMOS IC. Integrating conversion technique eliminates effect of fluorescent flicker. With SMBus interface, TSL2560 works with notebook and tablet PCs, while TSL2561 (I²C interface) suits LCD monitors, flat-panel televisions, and cell phones.
Original Press Release:
TAOS, Inc. Announces Light-to-Digital Converters That Simplify Ambient Light Sensing Implementation for Display Panel Products
New TAOS Digital Light Sensors Convert Light Intensity to Digital Signal Output with I²C or SMBus Interface
February 28, 2005 (Plano, TX) - Designers can now use ambient light sensing to differentiate their display panel products with two new light-to-digital converters announced today by Texas Advanced Optoelectronic Solutions ®, Inc. (TAOS). The patented digital light sensors convert light intensity to a digital signal output capable of direct I²C or SMBus interface. Each device is especially well suited for ambient light sensing in display backlighting and keyboard illumination applications.
The TSL2560 and the TSL2561 Light-to-Digital Converters are designed specifically for use in display panels (LCD, OLED, etc.) to help extend battery life and provide optimum viewing in diverse lighting conditions. These single-chip devices enable display panel backlighting, which can account for up to 30-40 percent of total platform power, to be managed automatically. Both devices also can be used to help control keyboard illumination based on ambient light conditions. The TSL2560 (SMBus interface) is intended for use in notebook and tablet PCs. The TSL2561 (I²C interface) is ideal for use in LCD monitors, flat-panel televisions and cell phones. The TSL2561 also finds applications in digital cameras where it can be used to manage exposure control. Other applications for both devices include street light control, security lighting, sunlight harvesting, machine vision and automotive instrumentation clusters.
"Raising the bar two years ago with our award-winning TSL2550 Ambient Light Sensor, TAOS recognized the need to help designers give their display panel products a competitive edge," said Glenn Lee, TAOS strategic marketing specialist for ambient lighting. "Now, we've increased the performance of our new digital light sensors to support not only as broad a range of ambient light sensing applications as possible, but also any type of application that requires accurate light sensing at a reasonable cost. Moreover, both devices can help designers significantly shorten time-to-market with their direct digital interface and TAOS software support. For example, a number of customers have already been able to design in the TSL2560 in less than 2-3 months."
The TSL2560 and the TSL2561 combine a visible light blocking photodiode with a broadband photodiode on a single CMOS integrated circuit. This combination enables either device to be used to calculate light intensity in lux over an effective 20-bit dynamic range with a 16-bit resolution without the use of an expensive filter. Two integrating analog-to-digital converters (ADC) convert the photodiode currents to an SMBus (TSL2560) or I²C (TSL2561) digital output that represents the irradiance measured on each channel. This output data can be input to a microprocessor where illuminance (i.e. ambient light level) in lux is derived using an empirical formula that is less than 200 bytes of code. The TSL2560 permits an SMB-Alert style interrupt and the TSL2561 supports a traditional style interrupt that remains asserted until the firmware clears it.
The TSL2560 and the TSL2561 can measure light levels ranging from 0.1 lux to 40,000 lux. No external circuitry is required for signal conditioning, thereby saving PCB real estate as well. In ambient light sensing applications, the integrating conversion technique used in both devices eliminates the effect of fluorescent flicker, thereby increasing the stability of the measurement. A single-supply operation (2.7 V to 3.3 V) makes both devices well suited for mobile applications. Moreover, when not in use, a power down mode ensures that the TSL2560 and the TSL2561 consume as little power (10.8 uW) as possible.
The TSL2560 and the TSL2561 Light-to-Digital Converters are available now from TAOS, Inc. and its authorized distributors. Both devices come in two standard 6-pin packages: Chipscale (CS) -- 1.7mm (1) x 1.2mm (w) x 0.7mm (h) - and Transfer Molded Board (T) - 3.8mm (l) x 2.6 mm (w) x 1.4mm (h). The TSL2560/61 has a suggested resale price of $1.29 in 1,000-piece quantities. In addition, an Evaluation Module with a USB interface is available from TAOS, Inc. and its authorized distributors with a suggested resale price of $125.00.
About TAOS, Inc. (Texas Advanced Optoelectronic Solutions)
Texas Advanced Optoelectronic Solutions (TAOS), Inc. is based in Plano, Texas. Established in 1998, the company develops, manufacturers and markets leadership integrated optoelectronic products. These devices combine precision mixed-signal functionality and photo-dectors on the same integrated circuit to produce advanced products with performance and cost advantages over conventional solutions. TAOS optoelectronic products include:
Light-to-Digital Converters (TSL2550, TSL2560, TSL2561)
Light-to Frequency Converters (TSL230R, TSL235R, TSL237, TSL245R)
Light-to-Voltage Converters (TSL12, TSL13, TSL14, TSL250R, TSL251R, TSL252R, TSL253R, TSL254, TSL257, TSL260R, TSL261R, TSL262R,, TSL267)
Color Sensors (TCS230, TSLR257, TSLG257, TSLB257)
Color Reflective Sensors (TRS1722, TRS1755, TRS1766)
CMOS Linear Sensor Arrays (TSL201R, TSLW201R, TSL202R, TSL208R, TSL210, TSL1301, TSL1401R, TSL1401CS, TSLW1401R, TSL1402R, TSL1406R, TSLl410R, TSL1412, TSL2014, TSL3301)
Custom and Semi-Custom Optoelectronic Devices and Assemblies
More information can be found at www.taosinc.com or by phone at 972-673-0759.
Trademarks
Texas Advanced Optoelectronic Solutions is a registered trademark of Texas Advanced Optoelectronic Solutions, Inc. (TAOS) of Plano, Texas.
