1:4 and 2 x 1:2 RS-422 Fanout Buffer, Triax I/Os

SKU:

$ 2,018.25

Item	Description
88000102-4	Cable, triple voltage, with modular plugs, Length in ft.
88000103-4	Cable, triple voltage, with modular plug and pig tail leads, Length in ft.

Product Description
Diagrams
Applications
Specifications
Documents

Applications:

RS-422 Fanout Buffer
Clock/Data Fanout Buffer
High Speed Digital Communications Systems Testing
Satellite Telemetry/Ground Station System Integration

Features:

f_max > 75 MHz
2.8 ns Typical Output Rise & Fall Times
1 ns Typical Channel to Channel Skew
Floating 124 Ω Differential Inputs for RS-422
4 Complementary 124 Ω RS-422 Outputs
Triax I/Os, Trompeter CBBJR79 or compatible
Switchable 1:4 Fanout or 2 x 1:2 Fanout Mode for simultaneous CLK/DATA distribution
Self-contained 1.3 x 2.9 x 6.0-in. unit
includes ±8.5 V/1.8 A AC/DC Adapter

Description

The PRL-414RSTR is a 1:4 fanout differential RS-422 line driver. It has two sets of floating 124 Ω differential inputs designed to accept RS-422 signals. The PRL-414RSTR high speed fanout line driver facilitates testing and integration of high speed digital communications circuits and distribution of satellite signals.

The PRL-414RSTR has two fanout modes, selectable by a toggle switch:

In the 1:4 mode (switch Up) D₁ is connected to all four outputs Q₁-Q₄, and D₂ is ignored. This mode is used for fanout of a single signal to four receivers.
In the 2 x 1:2 mode (switch Down) each of the two input signals is distributed to two outputs, with D₁ connected to Q₁-Q₂, and D₂ connected to Q₃-Q₄. This mode allows simultaneous distribution of Clock and Data signals to two receivers.

The four sets of differential outputs are 62 Ω back-terminated and designed for driving floating 124 Ω loads, normally the configuration used in RS-422 input circuits. The output swing is typically 1.40 V with a common mode voltage of 1.55 V. .

Because every output is independently buffered, unused outputs do not require termination, and outputs can even be shorted without affecting other outputs. These applications would not be possible with a passive splitter or powered distribution amplifier.

Multiple units of PRL-414RSTR can be cascaded for wider fanout, such as 1:16 or higher. The PRL-414RSTR can be combined with other PRL products and integrated into a rack-mount system using PRL's modular rackmount kit, PRL-MRK3-1.

All I/Os are Triax, using Trompeter CBBJR79 or equivalent, and will mate with any Trompeter 70-series Triax Cable Plug with 3 lugs, or compatible connector.

The PRL-414RSTR is supplied with a ±8.5 V/1.4 A AC/DC adapter and housed in a 1.3 x 2.9 x 6.0-in. extruded aluminum enclosure. Available accessories include voltage distribution modules and shielded twisted pair cables with Triax termination:

88001140-36 Cable, Shielded Twisted Pair, 124 Ohm Triax to Triax, 36"
88001140-48 Cable, Shielded Twisted Pair, 124 Ohm Triax to Triax, 48"

A related version with TTL/BNC inputs is also available, the PRL-414TRSBTR.

(0° C ≤ T_A ≤ 35° C)*

Symbol	Parameter	Min	Typ	Max	Unit	Comments
R_IN	Differential Input Resistance		124		Ω
R_INC	Common Mode Input Resistance		5k		Ω
R_OUT	Differential Output Resistance		124		Ω
V_IN	Input Voltage Range	-7		+12	V	Manufacturer’s specification; not tested at PRL
V_OL	Output Low Level		0.85		V
V_OH	Output High Level		2.25		V
V_OPP	Voltage Output, peak-to-peak		1.40		V
V_CMO	Output Common Mode Voltage¹		1.55		V
I_DC1	DC Input Current		300		mA	F = 25 MHz
I_DC2	DC Input Current		400		mA	F = 50 MHz
I_DC3	DC Input Current		500	550	mA	F = 75 MHz
V_DC	DC Input Voltage	+7.5	+8.5	+12.0	V
V_AC1	AC/DC Adapter Input Voltage, 120 V	103	115	127	V
V_AC2	AC/DC Adapter Input Voltage, 220 V	206	220	254	V
t_PLH	Propagation Delay to output ↑		20		ns
t_PHL	Propagation Delay to output ↓		20		ns
t_r/t_f	Rise/Fall Times (10%-90%)²		2.8	3.5	ns
t_SKEW1	Differential Skew between Q and Q		200	350	ps
t_SKEW2	Skew between any 2 outputs		1000	1500	ps	1:4 Fanout Mode
t_SKEW3	Skew between any 2 outputs		600	1000	ps	2 x 1:2 Fanout mode
f_max	Max Clock Frequency³	75	80		MHz
	Size	1.3 x 2.9 x 6.0			in.
	Weight	9			Oz	w/o AC adapter
	Shipping Weight	4			lb	w/AC adapter

Notes:

(1) V_CMO = (V_OH-V_OL)/2

(2) Rise and Fall times are measured using the PRL-860DTR, Low-Loss Triax Pickoff Tee. The through signals are driving a PRL-425TTR-C001, modified with a floating 124 Ω input, and the pickoff signals are driving 50 Ω scope inputs.

(3) f_max is measured using the PRL-177A Clock Generator driving the inputs via a PRL-Triax-SMA adapter and a PRL-425TTR-C001 as the receiver. The outputs of the PRL-425TTR-C001 are measured.

1:4 and 2 x 1:2 RS-422 Fanout Buffer, Triax I/Os

Applications:

Features:

Description

(0° C ≤ TA ≤ 35° C)*

Notes:

(1) VCMO = (VOH-VOL)/2

(2) Rise and Fall times are measured using the PRL-860DTR, Low-Loss Triax Pickoff Tee. The through signals are driving a PRL-425TTR-C001, modified with a floating 124 Ω input, and the pickoff signals are driving 50 Ω scope inputs.

(3) fmax is measured using the PRL-177A Clock Generator driving the inputs via a PRL-Triax-SMA adapter and a PRL-425TTR-C001 as the receiver. The outputs of the PRL-425TTR-C001 are measured.

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(0° C ≤ T_A ≤ 35° C)*

(1) V_CMO = (V_OH-V_OL)/2

(3) f_max is measured using the PRL-177A Clock Generator driving the inputs via a PRL-Triax-SMA adapter and a PRL-425TTR-C001 as the receiver. The outputs of the PRL-425TTR-C001 are measured.