• BI401-2G: 1µHz to 2.1GHz Square Wave, Plus DC
  • BI401-4G: 1µHz to 4.1GHz Square Wave, Plus DC
  • Ultra-Low Phase Noise and Jitter (< 0.3ps)
  • Practically Perfect™ 20-Digit Frequency Resolution
  • Frequency Switching Time: <250µs
  • Differential Outputs With PECL, NECL, LVDS Levels and 65ps Risetime
  • Single Ended Output With Up to 6V CMOS Levels
  • Unique Run-Time Level Calibration – Corrects for Load Termination Resistance
  • Programmable, Glitch-Free Phase Switching
  • Internal Timebase Reference – Choice of Standard TCXO (2ppm) or Optional Oven (0.02ppm)
  • Outputs of 10MHz or 100MHz Sine Wave or Square Wave Reference for Other Instruments

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The Perfect Clock

The BI401 Clock and Frequency Generator provides extremely accurate and stable square wave clock signals at up to 4.1GHz. Option -2G goes up to 2.1GHz, while -4G goes up to 4.1GHz. You can set the frequency with an unmatched resolution of 20 digits, and the jitter is below 0.3ps regardless of the frequency. There are two outputs – one single ended which provides up to 6Vpk-pk at 300MHz, and one differential with up to 1Vpk-pk at the full frequency range. The minimum frequency is 1µHz (one cycle in more than 11 days) and you can also output DC levels with 1mV accuracy. The instrument includes a high performance timebase and can serve as an excellent frequency reference for the whole system with very low phase noise. Both sine waves and square waves are available on the reference outputs.

Ultra-Low Phase Noise and Jitter

Using advanced synthesizer technology, this instrument produces clock signals with very low phase noise. The time domain jitter is less than 0.3ps regardless of frequency. This is in direct contrast to sinewave generators (RF generators) whose jitter increases at low frequencies. For example, if you use a 2Vpk-pk 10MHz sinewave as a system clock, its slew rate is 62.8V/µs or 62.8mV/ns. Therefore, 1mv of noise will add 16ps of jitter. If this signal is a sampling clock for a 14-bit ADC, the ADC will be degraded significantly. Since the output of the BI401 is a square wave whose slew rate is the same for all frequencies, there is no added jitter at low frequencies.


  • Reference Clock for PLL Testing
  • Sampling Clock for DACs and ADC
  • Synchronization and Digital System Clock
  • Low Jitter 1pps and Other Low Frequency Signals

BI401 Clock Generator

BI401 Clock Generator

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BI401 Virtual Front Panel Software

Actual phase noise measurements at 10 MHz, 622.08 MHz, and 1 GHz (spur were not removed)

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