SCF-2

Features

• Digital Inputs or Outputs
• (2) 3.5mm Jacks
• Scaling resistors
• Schottky Clamping Diodes
• Filter cap
• Ring pin brought to connector
  • Not used in Synth applications
  • Card can be used as a 3.5mm breakout
• (2) 4-40 mounting holes

Schematic

Used as Digital Input

• 550K input impedance presents light load
• R1/R3 - Input scale resistors
  • Ex: 5.0V control voltage to 3.0 V
• Clipping diodes protect inputs
• R1/C1 create input filter = 2.2mS = 454 Hz

Used as Digital Output

• Drive with 5V low output impedance source
• DNP R3, C1
• Use lower value for R1 (typically 200 Ohms, etc)
• Can leave Clipping Diodes to protect driver

Connectors

J1, J2 - 3.5mm Jacks

• Tip
• Sleeve

J3 - I/O Connector

• 2x4 Header, 0.1"
• Pinout

1. VCC
2. VCC
3. VP1 - Tip J1
4. VR1 - Ring J1 (not used in Synth applications)
5. VP2 - Tip J2
6. VR2 - Ring J2 (not used in Synth applications)
7. GND
8. GND