DRIVE50

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DRIVE50 P1080480-720PX.jpg

50 Ohm Driver Card[edit]

  • "TTL" Level Line driver
  • 50 or 75 Ohm output impedance
  • BNC or SMA output connector
  • 10K pull-up on input
  • Card is non-inverting
  • 1.5V-5.5V power
    • Typically 3.3V or 5V
  • 3-pin right angle 0.1" pitch input connector
  • (4) 4-40 mounting holes

Driver[edit]

  • 5x paralleled 74AC14 drivers
    • 24mA per pin max current output
      • Symmetric high-low drive levels
    • Short-circuit proof
      • 5V, 250 Ohms to ground is 20 mA (pins are rated for 24 mA)
      • 0.125 W resistor (5V output through 249 ohm resistor with output shorted to ground is 0.1 W)
      • 3.3V, 250 Ohms to ground is 13.2 mA (pins are rated for 24 mA)
      • 0.125 W resistor (3.3V output through 249 ohm resistor with output shorted to ground is 0.044 W)
  • Card has input buffer stage
  • Schmitt Trigger Input
  • 3.3V, 250 Ohm resistors (/5) for 50 Ohm output
    • Normal output = 10 mA per pin

Test[edit]

  • Manual or Automated test methods

Manual Test Method[edit]

  • Supply Vcc 3.3V to 5V and ground
  • Input is pulled up to Vcc
  • Measure output with BNC T
    • Should be 1/2 of Vcc with 50 Ohm terminator
    • Should be Vcc without terminator

Automated Test Software Method[edit]

DRIVE50 P1080485-720PX.jpg

Setup[edit]

Procedure[edit]

  • Connect 3 pin power cable to card
  • Connect BNC T to output of card
  • Connect BNC female from tester to BNC T male
  • Install 50 terminator to other side of BNC T
  • Connect USB C cable
  • Display will show
PulseGen/DRIVE50 V1.1
50 Ohm card
Set/Got Low
Term High = OK
  • All 3 LEDs are on

Application Example[edit]

GPS Frequency Standard[edit]

GPS Freq Std P18490-720px.jpg

  • GPS Frequency Standard
  • Card takes in PPS signal out of GPS module and drives 50 Ohm, 10 MHz Frequency Standard output on coax via BNC connector

Mechanicals[edit]

DRIVE50 MECHS REV1.PNG

Assembly Sheet[edit]