Ultra-compact Ambient Light Sensor ICs:
BH1620FVC (Analog Output) and BH1720FVC (Digital Output)

September 29, 2008 – ROHM formally announces the availability of two ultra-compact ambient light sensor ICs designed to meet the wide-ranging needs of the market – an analog output type (BH1620FVC) featuring 3-level current output gain and low 2.4V (min.) operation, and a digital output type (BH1720FVC) integrating a 16bit A/D converter for direct digital output that eliminates the need for external processing.

The two ICs deliver spectral sensitivity close to the human eye and enable measurement over a broad range, from darkness to direct sunlight. The sensors are available in the ultra-compact WSOF5 package type (1.6mmx1.6mmx0.5mm) – 60% smaller in volume than conventional units. In addition sensitivity variation has been significantly reduced, from the standard ±35% (analog) and ±38% (digital) to ±15%, through utilization of unique photo IC and trimming technologies.

The advanced features, combined with a compact package size and shutdown function that limits power consumption, make them ideal for high performance, energy-saving backlight adjustment in portable devices of all types, including compact LCD TVs, mobile phones, portable gaming consoles, and notebook PCs.

• Main features of the BH1620FVC and BH1720FVC

1. Ultra-compact WSOF5 package (1.6mm×1.6mm×0.55mm)
2. Spectral sensitivity close to that of the human eye (peak sensitivity waveform: 560nm)
3. Sensitivity variability: +/−15%
4. Built-in shutdown function
5. Compatible with 1.8V logic input interface
6. Three output current gain switching levels: 0.57µA/100lx, 5.7µA/100lx, 57µA/100lx (BH1620FVC)
7. Broad light measurement range: 0–100,000+lx (BH1620FVC), 0-65,528lx (BH1720FVC)
8. Wide operating voltage range: 2.4–5.5V (BH1620FVC)
9. Output proportional to brightness
10. I2C bus compatibility (F/S mode)
11. Integrated 16bit A/D converter eliminates the need for external processing
12. 50Hz/60Hz optical noise removal function ensures stable measurement (BH1720FVC)

New Product Bulletin for Compact Analog Ambient Light Sensor IC "BH1620FVC"(PDF:461KB)

New Product Bulletin for The World's Smallest Ambient Light Sensor IC "BH1720FVC"(PDF:504KB)

• Glossary

• Spectral sensitivity characteristics
  Normally depicted as a graph of the sensitivity characteristics relative to the optical wavelength, with wavelength on the horizontal axis and relative sensitivity on the vertical axis.
• Visual sensitivity
  The human eye is sensitive to light wavelengths from 380nm to 760nm, with the greatest sensitivity occurring at a wavelength of 555nm (green). The spectral sensitivity characteristics of the eye relative to this range of light are referred to as visual sensitivity.