1:4/1:2 TTL Complementary Fanout Line Driver


$ 1,092.50


  • TTL/CMOS Clock Distribution
  • 1:4 Fanout Line Drivers
  • Single-ended to Differential Conversion
  • 1 PPS Distribution/IRIG-B Distribution
  • High Speed Digital Communications System Testing
  • Mini-Modular Instrument


  • fmax > 100 MHz
  • Drives 100 ft of cable @ 80 MHz
  • 2 ns Typical Output Rise & Fall Times
  • TTL Compatible 50 Ω or 1 kΩ Input
  • Four in-phase 50 Ω TTL Outputs
  • Two invertible outputs for differential conversion
  • 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


The PRL-414C 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-414C can drive 100 ft of 50 Ω cables at clock rates greater than 80 MHz.

The inner two outputs of the PRL-414C can be inverted via a toggle switch to create two differential output channels that are compatible with many differential receivers, including most RS-422 receivers and our own PRL-425 series.

In 1:4 output mode the performance of the PRL-414C is generally similar to that of the PRL-414B, upon which it is based.

The input resistance of the PRL-414C 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/O’s are DC coupled and have BNC or SMA connectors.

The PRL-414C 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-414C is shown in Fig. 1.


prl-414CFig. 1, PRL-414C Block Diagram

Sample Applications and Related Products for PRL-414B

Crystal Clock Sources

  • PRL-171, Fanout Crystal Clock Source
  • PRL-172, Four-Phase Crystal Clock Source (f, f/2, f/4, f/8)
  • PRL-173, Two-Phase Crystal Clock Source (f, f/5)

RF Switches & Scanners

Frequency Dividers

  • PRL-220A, Four Phase Frequency Divider (f/2, f/4, f/8, f/16)
  • PRL-240A, Two Phase Frequency Divider (f/2, f/10)

Comparators/Sinewave Convertors

Logic Level Translators

PRL-470 High Speed Line Driver and Level Translator


  • Mounting Brackets
  • Extra AC/DC Adapters (one included with unit)
  • Voltage Distribution Modules, for sharing AC adapters among several modules
  • Cables


Symbol Parameter Min Typ Max Unit Comments
RIN LO Input Resistance Low Range 49.5 50 50.5
RIN HI Input Resistance High Range 990 1000 1010
ROUT Output Resistance 50
VIL TTL Input Low Level -0.5 0 0.5 V
VIH TTL Input High Level 2.0 2.4 5.0 V
VOL TTL Output Low Level 0 0.25 0.5 V RL=50 Ω
VOL TTL Output Low Level 0 0.25 0.5 V RL=50 Ω
VOH1 TTL Output High Level 2.2 2.5 V RL=50 Ω @ DC
VOH2 TTL Output High Level 4.4 5 V RL=1 MΩ @ DC
IDC1 TTL Output High Level 280 350 mA f ≤ 100 MHz
IDC2 DC Input Currents 220 250 mA f =50 MHz sq. wave(1)
VDC DC Input Voltages 7.5 8.5 12 V
VAC AC/DC Adapter Input Voltage 103 115 127 V
TPLH Propagation Delay to output ↑ 10 12 ns
TPHL Propagation Delay to output ↓ 8 12 ns
tr Rise Time (10%-90%) 2.2 3 ns f =50 MHz sq. wave
tf Fall Time (10%-90%) 1.8 3 ns f =50 MHz sq. wave
TSKEW Skew between any 2 outputs 500 1500 ps 1:4 mode, f =50 MHz sq. wave
FMAX1 Max. Clock Frequency(2) 100 120 MHz 1:4 mode, RG58C/U Cable length =3 ft
FMAX2 Max. Clock Frequency(3) 80 1:4 mode, RG58C/U Cable length =100 ft
FMAX3 Max. Clock Frequency TBD 1:2 Differential Mode
PWMIN Min. Pulse Width 4 ns ↑ Input
PWMIN Min. Pulse Width 6 ns ↓ Input
Size 1.3 x 2.9 x 2.9 in
Weight 5 Oz Excluding AC adapter
Shipping Weight 4 lb Including AC adapter
Unless otherwise specified, dynamic measurements are made with all outputs terminated into 50 Ω.
(1) For sharing a single PRL-760B, ±8.5 V ±1.4 A AC/DC adapter, the total current should not exceed 1.4 A.
(2) fMAX should not exceed 120 MHz; otherwise, damage of the unit due to overheating may result.
(3) fMAX2 is measured by connecting a second PRL-414B at the end of the 100 ft. cable.