PRL-4122, 1:22 Fanout 50 Ω TTL/CMOS Line Driver

Mini Modular Instruments > Fanout Buffers > PRL-4122

Applications:

• TTL/CMOS Clock Distribution
• 1:22 Fanout Line Driver
• High Speed Digital Communications System Testing
• 1 PPS/IRIG-B Signal Distribution
• Mini Modular Instrument

Features:

• f_MAX > 100 MHz
• Drives 100 ft of cable @ 80 MHz
• 1.8 ns Typical Output Rise & Fall Times
• 2.5 V into 50 Ω Typical
• TTL Compatible 50 Ω or 1 kΩ Input
• Twenty in-phase 50 Ω TTL Outputs
• Two auxiliary 50 Ω TTL Outputs suitable for cascading
• Active Low EN (Enable) Inputs for each bank of 10 outputs
• BNC I/O Connectors, plus two SMA auxiliary outputs
• DC Coupled I/Os
• Self-contained 3.0 x 6.8 x 4.0-in. unit includes an AC/DC Adapter

Description:

The PRL-4122-BNC is a 1:22 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-4122 can drive 100 ft of 50 Ω cables at clock rates greater than 80 MHz.

The PRL-4122 is implemented as a 1:4 fanout buffer (equivalent to a PRL-414B module) with two of its outputs externally cabled to the inputs of two 1:10 fanout buffers (each equivalent to a PRL-4110 module). The twenty outputs from the two 1:10 modules are in phase, while the additional two outputs of the 1:4 module are advanced by approximately 10 ns. These auxiliary outputs can be used to drive PRL-4110 or PRL-4220 units for additional in-phase outputs.

The input resistance of the PRL-4122’s primary input 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. The 50 Ω back terminated outputs typically deliver 2.5 V into 50 Ω or 5.0 V into Hi-Z loads. All I/Os are DC coupled and have BNC connectors, except for the auxiliary outputs which are SMA. SMA primary I/Os are available on special order (P/N PRL-4122-SMA).

Each 1:10 fanout bank also has an independent TTL-compatible EN input pulled down via a 1 kΩ resistor. When left open the Enable is active, and the fanout bank will output signals. Each bank can be disabled by driving its EN input high. A block diagram showing the equivalent input and output circuits of the PRL-4122 is shown in Fig. 1.

The PRL-4122 is housed in a 3.0 x 6.8 x 4.0-in. extruded aluminum enclosure and is supplied with the PRL-760C, ±8.5 V/±1.8 A AC/DC Adapter.

Related Products:

• PRL-4110, 1:10 Fanout 50 Ω TTL Line Driver
• PRL-4220, 2:20 Fanout 50 Ω TTL Line Driver, equivalent to two PRL-4110 units in a single enclosure
• PRL-4330, 3:30 Fanout 50 Ω TTL Line Driver, equivalent to three PRL-4110 units in a single enclosure

PRL-4122 | Detail | Diagram | Specifications | Datasheet