PRL-550NQ4X/PQ4X/LPQ4X Four Channel ECL/PECL/LVPECL Terminators

Mini Modular Instruments > ECL/PECL Terminators > PRL-550

Applications:

• Allow direct connection of ECL/PECL/LVPECL signals to 50 Ω input instruments
• Provide standard 50 Ω/V_TT terminations for ECL/PECL/LVPECL signals and Ground Referenced Outputs
• Testing and monitoring GHz ECL/PECL/LVPECL 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 ECL and 50 Ω /3 V for PECL
• Ground Referenced Outputs protect sensitive instruments
• SMA I/O connectors
• 4X attenuation
• Self-contained 1.3 x 2.9 x 2.2-in. unit includes AC/DC Adapter
• 16-channel rack-mountable unit also available for monitoring of multi-channel optical transceiver outputs

Description:

INTRODUCTION

ECL, PECL and LVPECL 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 ECL/PECL/LVPECL equipment outputs or the measurement instrument inputs may be made inoperative or damaged.

When driving a length of 50 Ω coaxial cable, an ECL/PECL/LVPECL output must be terminated into a 50 Ω load that is connected to a terminating voltage V_TT = V_CC -2 V. For ECL 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. For PECL circuits, where the supply voltage V_CC is +5 V, V_TT is +3 V. For LVPECL circuits, where the supply voltage is +3.3 V, V_TT is +1.3 V

ECL/PECL/LVPECL Terminators are level translators which convert ECL/PECL/LVPECL 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 ECL/PECL/LVPECL signals.

The PRL-550NQ4X, PRL-550PQ4X, and PRL-550LPQ4X are, respectively, Four Channel ECL, PECL, and LVPECL Terminators. The PRL-550NQ4X is designed to interface with ECL 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 PRL-550PQ4X is designed to interface with PECL circuits operating with a +5 V supply. Each input has an equivalent 50 Ω resistor terminated to a voltage V_TT = +3 V. The PRL-550LPQ4X is designed to interface with LVPECL circuits operating with a +3.3 V supply. Each input has an equivalent 50 Ω resistor terminated to a voltage V_TT = +1.3 V. The outputs of these Terminators are designed for direct connection to ground-referenced 50 Ω input instruments as shown in Figs. 1, 2 and 3, respectively. These near-ground level output signals* protect sensitive instruments and enhance measurement accuracy when these instruments are used.

Once an ECL, PECL, or LVPECL 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, PRL-550PQ4X and PRL-550LPQ4X 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.

*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 ECL/PECL device. When connected to an ECL/PECL 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 ECL, PECL or LVPECL device, the Terminator output Low Level is typically +50 mV.

Detail | Diagram | Specifications | Datasheet (550NQ4X/550PQ4X) | Datasheet (550LPQ4X)