MIDI-IN-OUT

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MIDI-IN-OUT REV1 FRONT 3D.png

Features[edit]

  • Module for Prototyping Synthesizer components
  • MIDI In/Out Jacks
  • Opto-isolated MIDI Input
  • 5V MIDI interface
  • 3.3V or 5V Serial connections
  • MIDI In is opto-isolated
  • (2) 4-40 Mounting holes

Connectors[edit]

J1 - MIDI In[edit]

MIDI IN SCHEMATIC.PNG

  • Opto-isolated input

J2 - MIDI Out[edit]

MIDI OUT SCHEMATIC.PNG

J3 - Serial/Power[edit]

  • Pinout
  1. V1 (3.3V or 5V
  2. 5V
  3. Receive data (out of card)
  4. Transmit (in to card)
  5. GND

J4 - Short V1 to 5V[edit]

  • Short J3-1 to J3-2
  • Used when Host Serial interface is 5V
  • Open when Host Serial interface is 3.3V

Drive Circuit[edit]

  • Two options
    • 4N25
    • CNY17-4

4N25 Optocoupler[edit]

4N28-DC-TransferRatio.PNG

4N28-CurrentTransferRatio-curve.PNG

  • LED Current vs voltage

4N28-LED-IvsV.PNG

  • Output transistor capacitance

4N28-OutputCapacitance.PNG

  • Switching Time

4N28-SwitchingTime.PNG

Param Val Unit
Vcc (MIDI) 5 V
Vf LED 1.2 V
Res ser 660 Ohms
If LED 5.76 mA
CTR (min) 0.2 A/A
Iout (min) 1.15 mA
Vout 3.3 V
R(min) 2.86 Kohms
Vout 5 V
R(min) 1.75 Kohms

CNY17-4 Optocoupler[edit]

CNY17-4 CTR.PNG

CNY17-4 FWD VOLTS CURRENT.PNG

CNY17-4 SWITCHING CHARACTERISTICS.PNG

Param Val Unit
Vcc (MIDI) 5 V
Vf LED 1.39 V
Res ser 660 Ohms
If LED 5.46969696969697 mA
CTR (min) 0.56 A/A
Iout (min) 3.0630303030303 mA
Vout 3.3 V
R(min) 1.07736446379106 Kohms
Vout 5 V
R(min) 1.63237039968342 Kohms
  • Use 2.2K pullup on Opto output

Assembly Sheet[edit]

MIDI-IN-OUT Rev 1 Assembly Sheet