2 Ch. NECL to LVDS Translator


$ 718.75


  • Converting Single Ended or Differential NECL Signals to LVDS Signals
  • High Speed Digital Communications systems Testing
  • High Speed SONET Clock Level Translation


  • fmax > 500 MHz
  • 1.1 ns Typical Output Rise & Fall Times
  • Single Ended or Differential 50 Ω/VTT Inputs
  • Complementary 50 Ω LVDS Outputs
  • SMA I/O Connectors
  • Triax Output connector option
  • Two channels for CLK/DATA translation
  • Self-contained 1.3 x 2.9 x 3.9-in. units include ±8.5 V/1.8 A AC/DC Adapters


The PRL-426N is a NECL-to-LVDS Logic Level Translator. The PRL-426N can receive either single-ended or differential NECL input signals, selected by a switch.

The differential outputs are 50 Ω back-terminated and are designed for driving floating 100 Ω loads, normally the configuration used in LVDS input circuits. The output swing is typically 600 mV with a common mode voltage of 1.2 V. Models with the TR suffix, e.g. PRL-426NTR, have Triax output connectors instead of the SMA connectors. These high speed translators facilitate testing of high speed digital communications circuits where conversion of NECL clock and data signals to LVDS level signals is often required.

The PRL-426N is designed to interface with -5.2 V or -3.3 V NECL circuits. In the differential input mode, both inputs D and D of the PRL-426N are terminated into 50 Ω/-2 V. In this mode, either one or both inputs can accept AC coupled signals as well. In the single input mode, signals should be connected to the D inputs only. The D inputs are switched internally to VBB, nominally -1.3 V, and termination resistors RT for the D input channels are changed to 62 Ω.

Each unit is supplied with a ±8.5 V/1.8 A AC/DC Adaptor and housed in a 1.3 x 2.9 x 3.9-in. extruded aluminum enclosure. Available accessories include voltage distribution modules for mounting multiple units.

Fig. 1: PRL-426N Dual Ch. NECL to LVDS Translator, SMA I/Os
Fig. 2: PRL-426NTR Dual Ch. NECL to LVDS Translator, Triax Outputs

(0° C ≤ TA ≤ 35° C)*

Symbol Parameter PRL-426N UNIT
Min Typ Max
RIN Input Resistance 49.5 50.0 50.5
ROUT Output Resistance 49.5 50.0 50.5
VTT D Input Termination Voltage (fixed) -2.2 -2.0 -1.8 V
VT1 D Input Termination Voltage (variable) -1.17 -1.30 -1.43 V
VT2 D Input Termination Voltage  -2.2 -2.0 -1.8 V
VOL Output Low Level   0.9   V
VOH Output High Level   1.5   V
VCMV Common Mode Voltage1   1.2   V
IDC1 DC Input Current, +8.5 V   85 100 mA
IDC2 DC Input Current, -8.5 V   -300 -330 mA
VDC DC Input Voltage ±7.5 ±8.5 ±12 V
VAC AC/DC Adapter Input Voltage 103 115 127 V
tPLH Propagation Delay to output ↑   2   ns
tPHL Propagation Delay to output ↓   2   ns
tr/tf Rise/Fall Times2 (10%-90%)   1.00 1.25 ns
tSKEW Skew between any two outputs   200 500 ps
fmax Maximum Clock Frequency 500 625   MHz
  Size 1.3 x 2.9 x 3.9  in.
  Weight, excluding AC adapter 7 Oz
  Shipping weight, including AC adapter 4 lb.


(1) VCMV = (VOH-VOL)/2 

(2) Rise and Fall times are measured with SMA output connector units only and with ground-referenced 50 Ω loads. 

(3) fmax is measured using a PRL-425N with the corresponding input connectors as the receiver. The NECL outputs of the PRL-425N are measured. 

Units with the Trompeter CBBJR79 Triax ouput connectors are tested using the PRL-425NTR, Universal Differential Receiver (Triax) with Differential NECL outputs, and the Trompeter PCGOW10PCG-36 shielded twisted pair cables.

All PRL products with Triax connectors use Trompeter P/N CBBJR79, Right Angle Circuit Board Bulkhead Jack, 3-lug (Numbered page 10, document page 11 of 142). Any Trompeter 70-series Triax Cable Plug with 3 lugs (e.g. PL75-9, 3-lug) will mate with CBBJR79.