The PRL-426 is a series of NECL-, PECL- or TTL-to-LVDS Logic Level Translators:
The PRL-426N/426P can receive either single-ended or differential input signals, selected by a switch. The input connectors on the PRL-426N/426P are SMA.
On the PRL-426T, the input is single-ended only, and the switch controls the input threshold (1.5 V or 1.0 V into 50 Ω). The input connectors on the PRL-426T are BNC.
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. The PRL-426NTR, PRL-426PTR, and PRL-426TTR 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/PECL 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 and the PRL-426P with +5 V PECL circuits. In the differential input mode, both inputs D and D of the PRL-426N are terminated into 50 Ω/-2 V, and those of the PRL-426P into 50 Ω/3 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 for the PRL-426N and 3.7 V for the PRL-426P, and termination resistors RT's for the D input channels are changed to 62 Ω.
The PRL-426T is designed to interface with TTL circuits. In cases where the signal source cannot drive TTL voltages into 50 Ω, the input threshold switch can be used to change the triggering voltage to 1.0 V.
Each unit is supplied with a ±8.5 V/1.4 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.
(0° C ≤ TA ≤ 35° C)*
|VTT||"D" Input Termination Voltage (fixed)||-2.2||-2.0||-1.8||2.7||3.0||3.3||N/A||V|
|VT||"D" Input Termination Voltage (variable)||-1.17/
|VOL||Output Low Level||0.9||0.9||0.9||V|
|VOH||Output High Level||1..5||1.5||1.5||V|
|VCMV||Common Mode Voltage1||1.2||1.2||1.2||V|
|IDC||DC Input Current||85/
|VDC||DC Input Voltage||±7.5||±8.5||±12||±7.5||±8.5||±12||±7.5||±8.5||±12||V|
|VAC||AC/DC Adapter Input Voltage||103||115||127||103||115||127||103||115||127||V|
|tPLH||Propagation Delay to output ↑||2||2||2||ns|
|tPHL||Propagation Delay to output ↓||2||2||2||ns|
|tr/tf||Rise/Fall Times2 (10%-90%)||1||1.25||1||1.25||1||1.25||ns|
|tSKEW||Skew between any two outputs||200||500||200||500||200||500||ps|
|fmax||Maximum Clock Frequency||500||625||500||625||250||300||MHz|
|Size||1.3 x 2.9 x 3.9||1.3 x 2.9 x 3.9||1.3 x 2.9 x 3.9||in.|
(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. fmax for the PRL-426T is currently limited by the lack of high frequency TTL drivers.
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.