New Monolithic Optical Proximity and Digital Ambient Light Sensor ICs from ROHM Semiconductor
Built-in ambient light sensor block for backlight dimming, spectrum sensitivity close to human eye, economic power consumption
The new sensor ICs are able to drive three peripheral infrared LEDs through an integrated LED driver in the proximity sensor block. A receiver block in the sensor IC detects the light reflected from people or objects and analyzes the phase difference. Designers just have to connect the IC to the host system to screen movement a couple of cm above the sensor IC.
Integrated ambient light sensor block suitable for backlight dimming
The BH1771GLC's built-in ambient light sensor reduces power consumption in devices equipped with an LCD in a variety of environments by controlling the backlight brightness based on ambient conditions. In addition, in order to prevent malfunctions during conversation or key operation (i.e. when the user's face/a finger is nearby) a proximity sensor is integrated that detects objects and prevents corresponding operations. Also, the backlights are turned off during this time in order to reduce power consumption. ROHM provides both dimming and malfunction prevention capability on a single chip.
The ambient light sensor features spectral sensitivity characteristics close to the human eye, resulting in stable high sensitivity, regardless of light source (i.e. incandescent, fluorescent, sunlight). The result is optimum performance and visibility in a variety of environments.
In order to increase operation time especially of battery-driven portable devices, the internal components must deliver added functionality. Meeting this requirement, the ambient light sensor and proximity sensor blocks of the BH1771GLC family feature intermittent operation that further reduces power consumption.
- Shutdown, measurement interval and proximity detection sensitivity set via I2C
- Compact 2.8 x 2.8 x 0.9mm package: WLGA010V28
Proximity sensor block
- Touchless motion detection function
- Digital 8bit output (I2C)
- Detection distance: 10 - 100mm (set via I2C)
- IrLED current driver built in
- Integrated sunlight cancelling circuit
- Measurement interval range: 10ms - 2000ms
- Digital 16bit output
- Reduced sensitivity variation (±15%)
- Measurement interval can be set between 100ms and 2000ms
BH1771GLC IC samples and volume production are available.
In addition to proximity sensors ROHM provides a wide range of sensors for many different purposes such as Hall sensors, temperature sensors or sensor backend ICs.
ROHM Semiconductor GmbH
ROHM Semiconductor - a name which stands for quality in the electronic industry with over 21,000 employees who produce a wide range of internationally marketable products, such as integrated circuits, diodes, transistors, resistors, tantal capacitors, display units, and special designs, in state-of-the-art manufacturing plants in Japan, Korea, Malaysia, Thailand, the Philippines and China. Since 2009, OKI Semiconductor is part of ROHM Semiconductor Group. ROHM in Europe serves the EMEA region (Europe and Middle East) with a staff of 170 in our design center / sales locations all over Europe. For further information please contact www.rohmeurope.com