• Direct Time Measurement of Pulse Trains
  • Measure Jitter, Frequency, Time Interval (Skew), Pulse Width, Risetime, Event Timing, Time Interval Error (TIE), and More
  • 8ps Single-Shot Resolution (12 Digits/s Frequency)
  • DC to 400MHz Frequency Range for all Measurement Functions Including Pulsewidth, Plus a Prescaler for Frequency and TIE Measurements (2.5 GHz for B220, 5 GHz for BI221)
  • Up to 1 Million Continuous Zero Dead Time Measure-ments Per Second
  • 1ns Minimum Pulse Width
  • Highly Sophisticated and Flexible Arming (Triggering)
  • PCI Interface (BI220) or PXI Interface (BI221) for Super High Throughput (legacy or hybrid)
  • On-board Memory for 8 Million Measurements – Can Be Read While Measurements are Taking Place

PDF Icon  Full Specifications


BI220 Counter / Time Interval Analyzer

More Tests in Less Time

The BI220/BI221 are high performance time and frequency measurement instruments. Their high resolution and through-put, combined with continuous measurement capability, allow you to make measurements that are not possible with tradi-tional time-interval counters. For example, they can timetag events (edges of an input pulse train) at a rate of 1 million per second continuously to on-board memory, while each of the edges is measured with 8 ps resolution. This provides them with the capa¬bility to analyze the dynamic variations in pulse timing, pulsewidth, or frequency. In other words, the difference be¬tween time interval analyzers and traditional counter/timers is analogous to the difference between voltmeters and scopes. Measure¬ments can also be streamed continuously over the PCI interface allowing unlimited acquisition at high rates.

Full-Featured Instrument

The BI220/BI221 are full instruments-on-a-card with all the features and capabilities you would expect in bench-top in-struments including high quality inputs, built-in NIST traceable calibration, and software and hardware that deliver fully com-puted results. The instruments have 10 measurement functions such as Fre¬quency, Time Interval and Pulsewidth. All functions work di¬rectly on the input signal at frequencies up to 400 MHz without any prescaling. This means that you can measure pulses as narrow as 1 ns, occurring at frequencies up to 400 MHz, or the skew between two signals at 400 MHz. There is also an optional prescaler for each input channel which allows frequency and period measurements to 2.5 GHz (BI220) or 5.0 GHz (BI221).


  • PLLs and frequency modulation – measure jitter, time interval error and settling time
  • Ultrasonic and radar pulse timing
  • Optical and magnetic disk drive – measure jitter, risetime, and bit timing directly
  • Oscillators and crystals – measure frequency, start-up time and time interval error
  • Pulse width modulated signals – measure variations over time
  • Time stamping of events in real time
  • Nuclear physics

PDF Icon   App note: Clock Chip and Oscillator Testing
PDF Icon  App note: Frequency Reference Comparison


BI221 Counter / Time Interval Analyzer

The inputs of the instruments include programmable termina-tion voltages. This feature is seldom found even in the best of the bench-top instruments. You can select by software control either a 1M Ohm impedance to ground, or a 50 ohm load which is terminated to an accurately programmable volt¬age between -3 V and +3 V. This allows you to connect ECL, PECL, or CML sources directly to the instruments with the proper loading.

Easy to Use Software

The software for the BI220/BI221 is designed for ease of use and extremely high performance. The driver software (Windows and Linux) automatically manages the streaming of measure¬ments at the high rates which are possible with the PCI inter¬face. The front panel soft¬ware for Windows allows you to easily set up multiple simul¬taneous displays of the meas¬urements. This gives multiple views of the same data, or differ¬ent func¬tions from the same data. For example, you can set up the display to show a graph of the frequency of the signal vs. time, plus a tabular display of the same results, plus a graph of the time deviation of the signal vs. time, all from the same measure¬ment acquisition run. The front panel can also run multiple instruments simultane¬ously. All instrument models use the same driver for easy migration between models.

The screen image below is from an actual measurement of a 400 MHz clock. One thousand single channel measurements were taken. The tabular display shows 1000 frequency measurements and the times and event numbers when they were taken. The digital display shows the statistics on period cal-culations of the same data. The graph display shows the TIE (Time Interval Error) calculations vs. time. Note that all 1000 measurements were taken in less than 1 ms and the resolution of the instrument is clearly evident with the Y axis of the graph at 5 ps per division.

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