Time converter clock3/8/2024 ![]() A solution is using a hybrid counter architecture. Binary counters, for example, need a fast carry architecture because they essentially add one to the previous counter value. High clock rates impose additional design constraints on the counter: if the clock period is short, it is difficult to update the count. One might, for example, multiply the crystal reference oscillator by 100 to get a clock rate of 1 GHz (1 ns resolution). ![]() To get better resolution, a phase-locked loop frequency multiplier can be used to generate a faster clock. High stability crystal oscillators are usually relative low frequency such as 10 MHz (or 100 ns resolution). Typically a TDC uses a crystal oscillator reference frequency for good long term stability. ![]() The accuracy of the measurement depends upon the stability of the clock frequency. To get finer resolution, a faster clock is needed. In that approach, the measurement is an integer number of clock cycles, so the measurement is quantized to a clock period. When an event occurs, the counter's value is captured in an output register. The current contents of the counter represents the current time. In its simplest implementation, a TDC is simply a high- frequency counter that increments every clock cycle. If the required time resolution is not high, then counters can be used to make the conversion. Coarse measurement A CMOS (rotary) traveling wave oscillator or delay line or distributed amplifier runs at a flip-flop compatible frequency, but has sharper edges and sub-edge resolution In an all-digital phase-locked loop (ADPLL), a TDC measures the phase shift and its result is used to adjust the digital controlled oscillator (DCO). electrons, photons, and ions) are detected.Īnother application is cost-effective and non-mechanical water flow metering by measuring the time difference between ultrasound pulses that travel through the flow and arrive at different times depending on the flow speed and direction. TDCs are used to timestamp events and measure time differences between events, especially where picosecond precision and high accuracy is required, such as the measurement of events in high energy physics experiments, where particles (e.g. This pattern is seen in many physical experiments, like time-of-flight and lifetime measurements in atomic and high energy physics, experiments that involve laser ranging and electronic research involving the testing of integrated circuits and high-speed data transfer. Measurement is started and stopped when the rising or falling edge of a signal pulse crosses a set threshold. TDCs are used to determine the time interval between two signal pulses (known as start and stop pulse). In some cases interpolating TDCs are also called time counters (TCs). In electronics time-to-digital converters (TDCs) or time digitizers are devices commonly used to measure a time interval and convert it into digital (binary) output. Some applications wish to measure the time interval between two events rather than some notion of an absolute time. For example, a TDC might output the time of arrival for each incoming pulse. In electronic instrumentation and signal processing, a time-to-digital converter ( TDC) is a device for recognizing events and providing a digital representation of the time they occurred. ( Learn how and when to remove this template message) ( May 2009) ( Learn how and when to remove this template message) Please help to improve this article by introducing more precise citations. This article includes a list of general references, but it lacks sufficient corresponding inline citations.
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