MIDI-IN-OUT

Features

• 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

J1 - MIDI In

• Opto-isolated input

J2 - MIDI Out

J3 - Serial/Power

• 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

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

Drive Circuit

• Two options
  • 4N25
  • CNY17-4

4N25 Optocoupler

• 4N25 Optocoupler
• DC Current Transfer Ratio

• LED Current vs voltage

• Output transistor capacitance

• Switching Time

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

• CNY17-Xxx

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

MIDI-IN-OUT Rev 1 Assembly Sheet