The PRL-444RS-SMA is a 4 Channel TTL to RS422 translator module.
The input resistance of the PRL-444RS-SMA inputs can be selected to be either 50 Ω or 1 kΩ by a common toggle switch. The 1 kΩ inputs are desirable when interfacing with low power circuits.
The four pairs of complementary outputs are designed for driving floating 124 Ω loads, normally the configuration used in RS422 input circuits. The output swing is typically 1.40 V with a common mode voltage of 1.5 V.
All I/Os are DC coupled and have SMA connectors. A block diagram showing the equivalent input and output circuits of the PRL-444RS-SMA is shown in Fig. 1.
The PRL-444RS-SMA is housed in a 1.3 x 2.9 x 2.9-in. extruded aluminum enclosure and is supplied with a ±9.0 V/±1.7 A AC/DC Adapter. The PRL-444RS-SMA may also be ordered without the power supply as part number PRL-444RS-SMA-OEM. A maximum of four units can share the included PRL-760D-120/220 AC/DC adapter using additional units of cable #88000102-4. If mounting is desired, a pair of the #35001420 mounting brackets can accommodate any two PRL modules of the same length.
A complementary product, the PRL-425QRT-SMA, performs the opposite conversion of 4 RS422 signals to 4 TTL signals. The coaxial outputs can also be adapted to off-the-shelf Cat5/Cat5e/Cat6a network cabling, and then back again to coax, via one or more PRL-RJ45-SMA adapters. A future version will have RJ45 I/O connectors as an option.
PRELIMINARY SPECIFICATIONS: (0° C ≤ TA ≤ 35° C)*
|VIL||TTL input Low Level||-0.5||0.0||0.5||V|
|VIH||TTL input High Level||2.0||2.4||5.0||V|
|VDC||DC Input Voltage||7.5||8.5||12.0||V|
|VAC1||AC/DC Adapter Input Voltage||103||115||254
|IDC1||DC Input Current @ 20 MHz||194||220
|IDC2||DC Input Current @ 40 MHz||290
|VOPP||Output Differential Voltage, peak-to-peak||1.40
|VCMO||Output Common mode voltage1||1.48||1.50
|tPLH||Propagation Delay to output ↑||TBD
|tPHL||Propagation Delay to output ↓||TBD
|tr/tf1||Rise/Fall Times (10%-90%)1||1.4||2.0
|fMAX||Max Clock Frequency||40
|tSKEW||Skew between any 2 rising edges||TBD||ps|
|tSKEW||Skew between any 2 rising/falling edges||250||ps|
|DTY||Duty Cycle @ 40 MHz||45/55|
|Size||1.3 x 2.9 x 2.9||in.|