1:4 TTL/CMOS Fanout Buffer and Line Driver

Applications:

• TTL/CMOS Clock Distribution
• 1:4 Fanout Line Drivers
• 1 PPS Distribution/IRIG-B Distribution
• High Speed Digital Communications System Testing
• Essential Lab Tool

Features:

• f_max > 100 MHz
• Drives 100 ft of cable @ 80 MHz
• 2 ns Typical Output Rise & Fall Times
• TTL Compatible 50 Ω or 1 kΩ Input
• 500 ps typical channel to channel skew
• Four in-phase 50 Ω TTL Outputs
• BNC or SMA I/O Connectors
• DC Coupled I/O's
• Self-contained 1.3 x 2.9 x 2.9-in unit includes an AC/DC Adapter

Description

The PRL-414B is a 1:4 fanout 50 Ω TTL Line Driver.  It is intended for distribution of high-speed clock and logic signals to multiple loads via long lines.  The 50 Ω back-terminated outputs can drive long lines with or without 50 Ω load terminations; With 50 Ω load terminations, however, all outputs of the PRL-414B can drive 100 ft of 50 Ω cables at clock rates greater than 80 MHz.  In one important application, the PRL-414B is used for distributing a precision clock signal to a number of test stations in the lab.

The input resistance of the PRL-414B can be selected to be either 50 Ω or 1 kΩ by a switch.  The 1 kΩ-input is desirable when interfacing with low power circuits.  All I/Os are DC coupled and have BNC or SMA connectors.

The PRL-414B is housed in a 1.3 x 2.9 x 2.9-in. extruded aluminum enclosure and is supplied with a ±8.5 V/±1.8 A AC/DC Adapter.  A maximum of four units can share a single AC/DC adapter using the PRL-730 voltage distribution module.  If mounting is needed, a pair of the #35001420 mounting brackets can accommodate any two PRL modules of the same length.  

A block diagram showing the equivalent input and output circuits of the PRL-414B is shown in Fig. 1.