The ISL29501 overcomes the shortcomings of traditional amplitude-based proximity sensors and other ToF solutions that perform poorly in lighting conditions above 2,000 lux, or cannot provide distance information unless the object is perpendicular to the sensor. Alternative solutions are too expensive, bulky or power hungry for use in small form factor, battery-powered applications. Based on Intersil's patented technology, the ISL29501 sensor provides a small solution footprint and precision long-range accuracy up to two meters in both dark and bright ambient light conditions. Unlike competitive solutions, the ISL29501 allows customers to select the emitter and photodiode of their choice and configure a low power ToF sensing system customized for their application.
"Prior to Intersil's time-of-flight technology breakthrough, there was no practical way to measure distance up to two meters in a small form factor," said Andrew Cowell, senior vice president of Mobile Power Products at Intersil. "The innovative ISL29501 provides customers a cost-effective, small footprint solution that also gives them the flexibility to use multiple devices to increase the field of view to a full 360 degrees for enhanced object detection capabilities."
Intersil has received a number of patents of ToF with ambient illumination rejection, such as US8274037 "Automatic calibration technique for time of flight (TOF) transceivers" by David W. Ritter, Philip Golden, Carl Warren Craddock and US8530819 "Direct current (DC) correction circuit for a time of flight (TOF) photodiode front end" by David W. Ritter, Philip Golden, Carl Warren Craddock, Kevin Brehmer, and US8530819 "Direct current (DC) correction circuit for a time of flight (TOF) photodiode front end" by David W. Ritter, Itaru Hiromi.
- On-chip DSP calculates ToF for accurate proximity detection and distance measurement up to two meters
- Modulation frequency of 4.5MHz prevents interference with other consumer products such as IR TV remote controls that operate at 40kHz
- On-chip emitter DAC with programmable current up to 255mA allows designers to choose the desired current level to optimize distance measurement and power budget
- Operates in single shot mode for initial object detection and approximate distance measurement, while continuous mode improve distance accuracy
- On-chip active ambient light rejection minimizes or eliminates the influence of ambient light during distance measurement
- Programmable distance zones: allows the user to define three ToF distance zones for determining interrupt alerts
- Interrupt controller generates interrupt alerts using distance measurements and user defined thresholds
- Automatic gain control sets optimum analog signal levels to achieve best SNR response
- Supply voltage range of 2.7V to 3.3V
- I2C interface supports 1.8V and 3.3V bus
The ISL29501 ToF processing IC is available now in a low profile 4mm x 5mm, 24-lead TQFN package and is priced at $4.87 USD in 1k quantities.