Greater precision enhances time-to-digital converter
Improved speed and precision together with low power consumption are enhancements made to ams’s time-to-digital converter (TDC) offering. The new TDC-GPX2 also features standard low-voltage differential signalling (LVDS) and serial peripheral (SPI) interfaces, and a new, smaller 9mm x 9mm QFN64 package.
TDCs from ams, which can measure short time intervals with great precision, are widely used in light detection and ranging (LIDAR) and laser-ranging devices, in positron emission tomography (PET) medical scanners, and in automated test equipment (ATE).
The introduction of the TDC-GPX2 means that these applications can benefit from increased resolution up to 10ps and a new high sampling rate of up to 70 Msamples/s. The TDC-GPX2 is an integrated four-channel converter IC offering single-measurement resolution of up to 20psrms per channel in normal mode.
Operating in dual-channel high-resolution mode, it can achieve a maximum resolution of 10psrms with 5ns pulse-to-pulse spacing. The superior performance of the TDC-GPX2 has been achieved without sacrificing power efficiency: The new product uses between 60mW and 450mW in normal operation, and draws just 60µA in stand-by mode. The combination of higher precision and a higher sampling rate means that LIDAR systems in cars, drones and robots will be able to achieve better object detection and avoidance.
This is the result of the more detailed and accurate ranging measurements, with a wider field of view that they will be able to take.
In virtual- and augmented-reality applications, the new, higher sampling speed and greater precision will support real-time 3D image rendering in unprecedented detail.
The new, higher sampling speed and greater precision will also enable PET scanners to achieve greater contrast while reducing the patient’s exposure time. ams has put particular emphasis on making the TDC-GPX2 easy to implement in end-product designs, providing standard interfaces and requiring few external components.
The chip also includes a driver for a quartz reference clock, which can be used for automatic calibration alternatively to the reference input. In addition, ams supplies an evaluation kit, the GPX2-EVA-KIT, which includes a programmer and GUI software for PCs, enabling users to configure and connect their Start and Stop signals and begin taking sample time measurements within minutes.