Time-to-digital converter offers precision for LiDAR applications

The AS6501 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 20ps per channel, or 10ps in dual-channel high resolution mode, and captures measurements at very high speeds of up to 70Msamples/s.

Single-beam laser ranging systems based on the precise, high speed AS6501 can render extremely accurate and detailed outlines of objects in the field of view - an essential requirement of new assisted and autonomous driving systems in vehicles.

Positron Emission Tomography (PET) medical imaging systems can also use the AS6501 to produce highly detailed images of a patient’s body.

By optimising the AS6501 for single-beam applications, ams has been able to combine very high performance with compact dimensions. The two-channel AS6501 is housed in a QFP48 package measuring just 7x7mm, 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.

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 just 450mW at a supply voltage of 3.3V. Stand-by current is 60µA.

The AS6501 can also be used in designs based on a microcontroller which require a Serial Peripheral Interface (SPI). The AS6501 features a four-wire SPI for configuration settings, which can also optionally be used for data read-out.

"By creating a compact version of our highly regarded TDC family with two channels, ams has been able to make high speed time-of-flight measurement possible in a wider range of applications, including those with tight space and cost constraints, while maintaining the extremely high performance of the successful TDC-GPX2 device,” said Norbert Breyer, Product Manager at ams.