NECL Crystal Clock Source, 2 Channels, SMA Outputs


$ 948.75


  • Precision Clock Source for High Speed Digital systems (SONET, SDH, ATM, Ethernet, Hypertransport, Firewire/1394, etc)
  • Differential NECL Clock Driver
  • SONET Clock Generator
  • An Essential Lab Tool for Working with NECL Circuits


  • 50 ps typical edge jitter
  • 50 ps typical skew between f, f outputs
  • 50, 200, 400, 500 and 622.08 MHz crystal frequencies in stock
  • Custom crystal frequencies available
  • Complementary outputs drive 50 Ω loads terminated to -2 V or AC coupled 50 Ω loads
  • DC coupled outputs compatible with ECLinPS or 100KH Devices
  • SMA I/O Connectors
  • Ready-to-Use 1.3 x 2.9 x 2.2-in. Module includes a -12 V AC/DC Adapter


The PRL-170N is a ready-to-use NECL crystal clock source module with differential outputs suitable for driving 50 Ω loads terminated to -2 V or AC-coupled 50 Ω loads. Standard crystal frequencies provided are 50 MHz, 200 MHz, 400 MHz, 500 MHz and 622.08 MHz. Other crystal frequencies are also available.

The PRL-170N is an essential laboratory tool in applications where a precision and low jitter high frequency clock source is required.

Model number designation is PRL-170N-xxx, where "xxx" represents the user specified clock frequency in MHz, such as 200 or 622, etc.

The PRL-170N is housed in a 1.3 x 2.9 x 2.2-in. extruded aluminum enclosure and supplied with a ±8.5 V AC/DC adapter.

PRL-170N Block Diagram

(0° C ≤ TA ≤ 35° C)*

Symbol Parameter PRL-170N Unit Comments
Min Typ Max
VOL Output Low Level -1.95 -1.70 -1.48 V
VOH Output High Level -1.13 -0.90 -0.81 V
IDC DC Input Current -300 -200 mA Xtal freq. dependent
VDC DC Input Voltage -12 -8.5 -7.5 V
VAC AC/DC Adapter Input Voltage 103 115 127 V
tr/tf Rise/Fall Times (20%-80%), f, f outputs 500 650 ps Note (1)
tSKEW1 Skew between f and f outputs 20 75 ps
fMAX Max crystal clock frequency 825 MHz Note (2)
∆f Frequency Stability 100 ppm
Frequency Jitter 20 ps
Positive Duty Cycle 50 40 %
Size 1.3 x 2.9 x 2.2 in.
Weight excl. AC adapter 5 Oz
Shipping weight incl. AC adapter 4 lb.
*All dynamic measurements are made with outputs terminated into 50 Ω/-2 V, using the PRL-550NQ4X , four channel NECL Terminator, connected to a 50 Ω input sampling oscilloscope.
The output rise and fall times are measured with with all inputs terminated into 50 Ω/VTT. For best performance all outputs should be terminated into 50 Ω/VTT or else AC- coupled into 50 Ω loads. If a single output is used, its complement must be terminated; otherwise output waveform distortion will occur. If one pair of complementary outputs is used, the other complementary pair may remain unterminated. Use the PRL-550 Series, four channel NECL Terminator, for the 50 Ω/VTT termination and for connection of NECL signals to 50 Ω input oscilloscopes. The PRL-ACT-50, Dual Channel AC-Coupled 50 Ω Terminator, may also be used to provide the 50 Ω/VTT termination. If preservation of DC levels is not required, then the PRL-SC-104, 0.1 µf DC block or a 12 dB AC-coupled attenuator may be used to connect the NECL outputs to 50 Ω input instruments.
(2). The maximum attainable frequency of the PRL-170 is dependent on the availability of high frequency crystal clock oscillators, currently limited to 825 MHz.