Home
Home
Here's a quick technical description of how the Sine Wave Thing works:
The CD4015 is a serial in / parallel out shift register that cycles a
shifted image of a square wave, starting with all zeroes then ones due to
the opamp which acts as an inverter, then zeroes again.
This pattern of stimulus gets applied to the resistive summation network
which has resistor values chosen to make a sine wave.
So around and around it goes, creating an 8-step sinusoid each time.
Then the output buffer, a voltage follower, buffers the output to the
breadboard connector.
This module will soon be available in our
store.
To use the module, just hook up VDD and Ground, then apply a clock signal or digital audio signal to the Clock input. Connect the Output signal to a Stereo Out module and you've got sound!
Addition pins include a Reset which is pulled low with a 100k Ohm resistor. This is rarely necessary but if you have designed a Reset into your system or would like to synchronize the sine wave, then there's your pin. Also available is an unbuffered version of the output signal and unbuffered VDD/2 from a voltage divider with a filter cap (100k Ohm resistors and a 0.1uF cap). The U Output signal is useful in case you would like to smooth the stair-stepped output to get even more smooth sounding audio. Just connect a small capacitor to the U Output pin and shunt it to Ground to filter the sine wave.