2 Ch. Translator, NECL to RS422

SKU:

$ 1,620.35

Item	Description
88000102-4	Cable, triple voltage, with modular plugs, Length in ft.
88000103-4	Cable, triple voltage, with modular plug and pig tail leads, Length in ft.

Product Description
Diagrams
Applications
Specifications
Documents

Applications:

Essential tool for interfacing with High speed data communications equipment
Converts single-ended or differential 50 Ω SMA NECL inputs to differential 124 Ω RS-422 Triax outputs

Features:

400 MHz maximum Clock Rate
Internal Single Ended or Differential 50 Ω/-2 V Input termination
Differential 124 Ω RS-422 Outputs
Ready-to-Use 1.3 x 2.9 x 3.9-in. modules, include AC/DC Adapters

Description

The PRL-422NECL is a dual channel, high speed logic level translator designed specifically for use with high speed data communications applications. The PRL-422NECL converts single ended or differential 50 Ω NECL inputs to differential 124 Ω RS422 outputs. A functional block diagram is shown in Fig. 1.

The differential inputs of the PRL-422NECL have SMA connectors. A switch selects either single-ended or differential inputs. In the differential input mode, both inputs D and D are terminated internally into 50 Ω/-2 V, and, therefore, 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 V_BB, nominally -1.3 V, and termination resistors R_T's for the D input channels are changed to 62 Ω.

The outputs of the PRL-422NECL have two triax connectors, and they are designed to interface with the 124 Ω differential Serial Data/Data or Clock/Clock inputs of the data communications equipment. Internal pull-down resistors enable these outputs to drive differential 75 Ω loads as well.

The PRL-422NECL is housed in an attractive 1.3 x 2.9 x 3.9-in. extruded aluminum enclosure. Optional mounting brackets are available. Each unit is supplied with a ±8.5 V/1.8 A AC/DC Adapter.

Fig. 1 PRL-422NECL Dual Ch. NECL to RS-422 Translator

*Since the high frequency signals to and from the 124 Ω I/O ports can not be easily measured, the 124 Ω I/O ports of these adapters were first cascaded using shielded twisted pair cables, Trompeter P/N PCGOW10PCG-36 or equivalent. Input signals were applied to the 50 Ω inputs of the PRL-422NECL, and outputs of the PRL-422RS were terminated into 50 Ω /-2 V, using the PRL-550NQ4X, four-channel ECL Terminator, connected to a 50 Ω input sampling oscilloscope.

Notes:

The 50 Ω output rise and fall times were measured with both the Q and Q outputs terminated into 50 Ω /-2 V. If one output is not terminated, both the rise and fall times will increase by approximately 15%, and output waveform degradation will occur.
f_MAX is measured using the differential input mode(switch up). The differential outputs are first divided by four, using the PRL-255, ÷2 and ÷4 frequency divider module, and then measured using the PRL-550NQ4X, four channel ECL Terminator, connected to a sampling 'scope.
Trompeter P/N CBBJR79.
Trompeter P/N PCGOW10PCG-36

(0° C ≤ T_A ≤ 35° C)*

Symbol	Parameter	PRL-422NECL			Unit
Symbol	Parameter	Min	Typ	Max	Unit
R_IN	Input Resistance	49.5	50	50.5	Ω
V_TT	Input Termination Voltage	-1.8	-2.0	-2.2	V
I_DC1	DC Input Current, +8.5 V		30	60	mA
I_DC2	DC Input Current, -8.5 V		-250	-300	mA
V_DC	DC Input Voltage	±7.5	±8.5	±12	V
V_AC	AC/DC Adapter Input Voltage	103	115	127	V
t_PLH	Propagation Delay to output ↑		2000		ps
t_PHL	Propagation Delay to output ↓		2000		ps
t_r/t_f	Rise/Fall Times¹ (20%-80%)		NA		ps
f_max	Maximum Clock Frequency²	400	600		MHz
t_SKEW1	Skew between outputs		20	200	ps
t_SKEW2	Skew from unit to unit		40	400	ps
	Input Connector	SMA
	Output Connector	Triax³
	Input Cables	50 Ω Coax
	Output Cables	124 Ω TP⁴
	Size	1.3 x 2.9 x 3.9			in.
	Weight, excluding AC adapter	7			Oz
	Shipping Weight, including AC adapter	4			lb.

Notes:

(1). The 50 Ω output rise and fall times were measured with both the Q and Q outputs terminated into 50 Ω/-2 V. If one output is not terminated, both the rise and fall times will increase by approximately 15%, and output waveform degradation will occur.

(2). f_MAX is measured using the differential input mode (switch up). The differential outputs are first divided by four, using the PRL-255 ÷2 and ÷4 frequency divider module, and then measured using the PRL-550NQ4X, four channel ECL Terminators, connected to a sampling scope.

(3). Trompeter P/N CBBJR79.

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.

PDF Datasheet