In the first graph we see the effect that the load (speaker) has on the output power available. As we can see, there
is an inverse relationship between the load resistance and the output power. To get the most out of the Noisy
Cricket, it’s recommended to use a 4Ω speaker in mono operation and an 8Ω in stereo.
This next graph we’re still looking at the output power versus the load resistance, but instead of the power being
measured in watts, it’s in milliwatts. So what gives? The variable that was changed was the supply voltage, VDD.
In the first graph, VDD was equal to 5V, and the second VDD is set to 2.7V. With approximately half the voltage,
the output power is around four times less with the same load. While the amplifier functions down to 2.4V, it will
mean that you have less output power available if your load resistance remains constant (thanks to ohm’s law). To
see the full effect the supply voltage has based on a few of the more common loads refer to the graph below.
With these graphs in mind and maximize the power output, we recommend a power supply voltage of 5V with a
current rating of at least 100mA. For the stereo amplifier, use 8Ω speakers. For a mono amplifier, use a 4Ω
speaker.
Resources and Going Further
Now that we know how to use the Noisy Cricket, it’s time to use it in your own project! For more information on the
Noisy Cricket, checkout the links below:
