2 Ch. Translator, TTL to Differential TTL


$ 1,130.45


  • 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


  • fMAX > 300 MHz
  • 1.1 ns Typical tr 
  • 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


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".

Fig. 1, PRL-420TD Block Diagram

(0° C ≤ TA ≤ 35° C)*

Symbol Parameter PRL-420TD Unit
Min Typ Max
RIN Input Resistance 49.5 50.0 50.5 Ω
ROUT Output Resistance 49.5 50.0 50.5 Ω
VTOSH Input Threshold Voltage (high) 1.4 1.5 1.6 V
VTOSL Input Threshold Voltage (low) 0.9 1.0 1.1 V
VIL TTL input Low Level -0.5 0.0 0.5 V
VOL TTL Output Low Level -0.1 0.0 0.5 V
VOH TTL Output High Level 2.0 2.5 2.6 V
IDC1 DC Input Current, +8.5 V 340 360 mA
IDC2 DC Input Current, -8.5 V -360 -340 mA
VDC DC Input Voltage ±7.5 ±8.5 ±12 V
VAC AC/DC Adapter Input Voltage 103 115 127 V
tPLH Propagation Delay to output ↑ 2 ns
tPHL Propagation Delay to output ↓ 2 ns
tr/tf(1) Rise/Fall Times (10%-90%) 1.2 1.4 ns
tSKEW Skew between any 2 outputs 150 400 ps
fMAX Max Clock Frequency 250 300 MHz
Size 1.3 x 2.9 x 3.9 in.
Weight, excl. AC adapter 7 Oz
Shipping weight, incl. AC adapter 4 lb.

*Unless otherwise specified, dynamic measurements are made with all outputs terminated into 50 Ω.

While we believe these models to be accurate, no representations are made as to accuracy or suitability for any application: