Motivation
This module provides high precision CV outputs in 1V (octaves) and 83,3mV (halves) steps. The 1V output goes from -5 to +5V. The 83,3mV steps goes from -5 to plus 5 steps (halves). This module is thought for all who are missing octave switches in some modules. Especially in VCO. With this module you can switch octaves and halves as well.
Specs and features
- High precision output from -5V to +5V in 1V steps (octaves)
- High precision output in 83,3mV steps, +/- 5 steps (Halves)
- Runs on +/-15V and +/-12V
- Power consumption around 30mA each rail
Implementation
Schematic
Scaled voltage reference schematic
Description:
The precision voltage is derived from the REF102. The negative voltage is provided with the INA105. It is crucial to match the resistors in the voltage dividers as good as you can. The outputs of the voltage dividers are buffered to avoid loading of the dividers. The resistors around the OpAmps must be matched as well. The one volt and the 83,3mV steps are added together with IC4A. The three outputs are individual buffered.
Calibration
- None
Building hints
- It is crucial to match the resistors in the voltage dividers as good as you can.
Special parts
- None
Download
Scaled voltage reference documentation downloadScaled voltage reference Gerber files download
Scaled voltage reference: Front view
Scaled voltage reference: Populated PCB
