4 Channel NECL Terminator

SKU:

$ 1,148.85

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:

Replacement for discontinued HP/Agilent/Keysight 10086A ECL Terminator
Allow direct connection of NECL signals to 50 Ω input instruments
Provide standard 50 Ω/V_TT terminations for NECL signals and Ground Referenced Outputs
Testing and monitoring GHz NECL signals in digital and wireless communication applications
Monitoring of optical transceiver outputs

Features:

43 ps Typical Rise Time (8 GHz equivalent bandwidth)
50 Ω/-2 V Input Termination for NECL
Ground Referenced Outputs protect sensitive instruments
SMA I/O connectors
12 dB (4X) attenuation
Self-contained 1.3 x 2.9 x 2.2-in. unit includes AC/DC Adapter

Description

INTRODUCTION

NECL logic levels are offset from ground. Without proper level shifting, these logic signals can not be connected to ground-referenced 50 Ω input instruments, such as sampling 'scopes, network analyzers, scanners and counters, etc. Otherwise, either the NECL equipment outputs or the measurement instrument inputs may be made inoperative or damaged.

When driving a length of 50 Ω coaxial cable, a NECL output must be terminated into a 50 Ω load that is connected to a terminating voltage V_TT = V_CC -2 V. For NECL circuits operating with a supply voltage of either -5.2 V or -4.5 V, V_CC is 0 V, and V_TT is equal to -2 V.

NECL Terminators are level translators which convert NECL signals into signals that can be connected to ground referenced 50 Ω input instruments and, at the same time, provide standard 50 Ω/V_TT terminations required by NECL signals.

PRODUCT DESCRIPTION

The PRL-550NQ4X is a Four Channel NECL Terminator designed to interface with NECL circuits operating with a -5.2 V or -4.5 V supply. Each input has an equivalent 50 Ω resistor terminated to a voltage V_TT = -2 V.

The outputs of these Terminators are designed for direct connection to ground-referenced 50 Ω input instruments as shown in Fig. 1, and a block diagram is shown in Fig. 2. These near-ground level output signals* protect sensitive instruments and enhance measurement accuracy when these instruments are used.

Once a NECL signal is translated through a proper Terminator, it can be routed through 50 Ω scanners and other high frequency measuring instruments for processing. Each PRL-550NQ4X Terminator is housed in an attractive 1.3 x 2.9 x 2.2-in. extruded aluminum enclosure and is supplied with a ±8.5 V AC/DC Adapter.

Fig. 1: NECL driving a 50 Ω input instrument using the PRL-550NQ4X Terminator

Fig. 2, PRL-550NQ4X Diagram

(0° C ≤ T_A ≤ 35° C)*

Symbol	Parameter	PRL-550NQ4X			Unit
Symbol	Parameter	Min	Typ	Max	Unit
R_IN	Input Resistance	49.5	50.0	50.5	Ω
V_TT	Input Termination Voltage	-2.2	-2.0	-1.8	V
V_OS	Output Offset Voltage*	-20	0	20	mV
	Signal Attenuation	11.8	12.0	12.2	dB
I_DC1	DC Input Current, +8.5 V		+60	+85
I_DC2	DC Input Current, -8.5 V		-125	-150
V_DC	DC Input Voltage	±7.5	±8.5	±12	V
V_AC1	AC/DC Adapter Input Voltage, 120 V	103	115	127	V
t_PLH	Propagation Delay to output ↑		475	575	ps
t_PHL	Propagation Delay to output ↓		475	575
t_r/t_f	Rise/Fall Time		43	61	ps
BW	Equivalent bandwidth	5.7	8.0		GHz
t_SKEW	Skew between outputs		20	50	ps
	Channel-to-Channel Cross Talk @ 1.4 GHz		34	40	dB
	Size	1.3 x 2.9 x 2.2			in.
	Weight, excluding AC adapter	5			Oz
	Shipping weight, including AC adapter	4			lb.

*The output offset and input termination voltages are factory set to 0 V and V_TT = V_CC-2 V, respectively, before the input is connected to an NECL device. When connected to an NECL device, the output low level will be slightly offset from ground depending on the low level output voltage of the connected device, which is typically V_CC-1.8 V. When its input is connected to an NECL device, the Terminator output Low level is typically +50 mV.