Thank you for the suggested SMT breakout boards above.
I am an electronics rookie like original writer of this thread. I have purchased a few of the Adafruit FX Mini Sound Boards ( http://www.adafruit.com/products/2342
) and use each of these with the Adafruit Mono 2.5W Class D Amplifiers ( http://www.adafruit.com/products/2130
). Nice quality products! I am running each unit with a 3 rechargeable 1.2V NiMh battery pack (for a 3.6V power supply). I noticed that when the battery pack runs low that the FX board works erratically until I recharge the batteries. I would like to implement the low-voltage cutoff circuit described above.
I plan to determine the specific voltage that the FX board starts to fail by testing the board with varying zener diode shunt circuits such as 2.9V, 3.0v, 3.1V, 3.2V, etc. Then I would like to use the above suggested voltage monitor IC ( http://www.onsemi.com/pub_link/Collateral/NCP300-D.PDF
) with a MOSFET so that power is completely shut off to the FX-Amplifier circuit before the erratic voltage value occurs . I need a bit of assistance to determine the specific Mosfet to use in this application. I would like to use the voltage monitor circuit without the need to add a microcontroller to my setup, as the FX board does not need to be hooked up to a microcontroller.
Digikey basically has the one version ( http://www.digikey.com/product-detail/e ... ND/2121364
) of the suggested voltage monitor that is available in quantity “1” for a voltage threshold of 3V (the lowest voltage acceptable in the FX spec sheet). These voltage monitor chips are listed as "Active Low" and "Push-Pull, Totem Pole" ( I am not certain what this means! ). The chip manufacturer has many other voltage choices which other distributors undoubtedly carry.
I assume (?) that since the above voltage monitor chip is Active-Low that I would want to use an "N" type of Mosfet, and saw that Adafruit sells the N-channel power MOSFET - 30V / 60A PRODUCT ID: 355 ( http://www.adafruit.com/product/355
I am uncertain looking at the voltage monitor sheet and the Adafruit Mosfet specs if the voltage monitor chip outputs sufficient voltage to turn on the gate of the Adafruit Mosfet, or if perhaps a different Mosfet is more suitable for this application. It also seems that the power rating for the listed Mosfet is a lot higher than what is needed for this setup.
In advance thank you for your help