Resources
AS3340 Chip breakdown
Power Supply
- Pins 16 (VCC Positive) and 3 (VEE negative)
- CANNOT be powered with +/- 15V, +/-12V without protection
- Voltage between VCC and VEE should be less than +24V
- Voltage between VCC and GND should be less than +18V
- Voltage between VEE and GND should be less than -6V
- A current limiting resistor is used in the datasheet when powering it with -15V
- You can power VEE with -5V without using a current limiting resistor
- When powering VEE with -15V, use an 820R current limiting resistor
- When powering VEE with -12V, use a 470R current limiting resistor
Sync
- Pins 6 (Hard SYNC) and 9 (Soft SYNC)
Output Levels
- Pins 4 (Pulse), 8 (Saw), and 10 (Triangle)
- Ramp - 2/3rds of the positive supply
- Triangle - 1/3rd of the positive supply
- Pulse - positive supply minus 1.3V
- Open emitter - requires a pulldown resistor to set the lower level
- With a +15V supply
- Ramp - 0 to 10V
- Triangle - 0 to 5V
- Pulse - 0 to 13.5V
- With a +12V supply
- Ramp - 0 to 8V
- Triangle - 0 to 4V
- Pulse - 0 to 10.7V
Scale pins
- Pins 1 (Scale1) and 2 (Scale2)
- For temperature compensation
High frequency tracking
- Pin 7
- Compensates for the way that the time taken for the internal comparator to switch becomes significant at higher frequencies
Timing capacitor
- Pin 11
- Use a good quality capacitor
- Low leakage, low tempco
- Polystyrene film is the best option
- 1nF value
Linear FM input
- Pin 13
- Sometimes not used by designers, a only bias network is present (1M5, 470R, 10n)
Note CV (Frequency CV) input
- Pin 15
- a virtual ground summing node
- Usually see a bias network (360K, 470R, 10n)
- Summing resistors connected to the node for CV sources