Dual-Channel TTL-to-Differential TTL Translator

Applications

• Converting TTL/CMOS signals to Differential TTL Signals
• Converting TTL/CMOS Signals to RS-422 Signals
• High Speed Digital Communications system testing
• 1 PPS/IRIG-B Line Driver
• Differential Line Drivers

Features:

• f_MAX > 300 MHz
• 1.1 ns Typical t_r 
• 50 Ω TTL/CMOS Input
• 1.5 V or 1.0 V Selectable Input Threshold
• Complementary 50 Ω TTL Outputs
• BNC Input/SMA Output Connectors
• DC-Coupled I/Os
• Self-contained 1.3 x 2.9 x 3.9-in. units including AC/DC Adapters

Description

The PRL-420TD is a dual channel single-ended input, differential output TTL Line Driver. Each channel has a 50 Ω TTL/CMOS compatible input and a pair of differential 50 Ω outputs for driving long lines with or without 50 Ω terminations. The input threshold voltage can be selected between 1.5 V and 1.0 V using a front panel switch. The 1.0 V threshold is useful when dealing with weak signals.
The PRL-420TD is intended for use in testing and interfacing of high speed digital communication circuits, where conversion from single-ended TTL/CMOS level signals to differential signals is often required. The differential TTL outputs can also drive RS-422 input circuits. It is an ideal building block that complements other PRL Level Translators, such as the PRL-450ND, PRL-450PD and PRL-460NPD, in systems integration applications where interconnections of signals having different logic levels are often necessary.
The PRL-420TD is a ready-to-use functional module housed in a 1.3 x 2.2 x 2.9-in. extruded aluminum enclosure and is supplied with a ±8.5 V AC/DC Adapter. BNC input and SMA output connectors are provided. A block diagram showing the equivalent input and output circuits of the PRL-420TD is shown in Fig. 1.

The PRL-420TD may be ordered without a power supply as “PRL-420TD-OEM” or with a NRTL-approved power supply (equivalent to PRL-765-1) as “PRL-420TD-NRTL”.