The AS6501 from ams is a two-channel time-to-digital converter (TDC) that is said to enable high-speed scanning and high precision in single-beam optical ranging equipment and medical imaging systems. The device features high-speed LVDS interfaces for the Start and Stop signals at the light source in optical ranging equipment and scanners, and LVDS measurement outputs. It can be used to measure the time-of-flight of optical signals to a precision of 20 ps per channel, or 10 ps in dual-channel high-resolution mode, and captures measurements at speeds of up to 70 Msamples/s.
The two-channel AS6501 is housed in a QFP48 package measuring 7 mm x 7 mm, a 40% reduction in board footprint compared to its four-channel counterpart, the TDC-GPX2. The AS6501, which includes on-board logic for measuring the time interval between the Start and Stop signals, requires few external components. Reportedly, power consumption is as much as ten times lower than that of competing TDCs that offer a similar level of precision: typical power consumption in normal operation is 450 mW at a supply voltage of 3.3V. Stand-by current is 60 µA.
The device can also be used in designs based on a microcontroller which require a serial peripheral interface (SPI). Additionally, it features a four-wire SPI for configuration settings, which can also optionally be used for data read-out.
The AS6501 is available now in production volumes. For more information, peruse the AS6501 datasheet.