Hi, I am hoping someone can help me choose a MOSFET for my application. I am using an ATMEGA328 MCU and an N-channel logic-level MOSFET to switch on and off a 12V power supply to a device that uses 25-300mA (the current varies over time). I need to keep power consumption of the system as low as possible. The MCU sleeps most of the time, switching on the 12V power for two minutes every hour (the timing is done with an IC2 clock chip alarm) for five months. The power to the MCU (and therefore the MOSFET's gate voltage) will start at 4.8V and may go as low as about 2.7V by the end.
Currently I am using an IRL540 MOSFET. It works, but I don't know if it's the best for when the gate voltage decreases. I'd like to find the best MOSFET for my application. I keep thinking that I'll get the hang of the datasheet, but so far I am not getting very far. I am stuck at very basic questions, like "Does Gate-Source Voltage mean the voltage coming from the MCU, or is it that voltage minus the source voltage?" This question by itself probably shows my level of expertise. I tried searching for "MOSFET for dummies" but that didn't help much.
I am thinking that before I invest more time with the datasheets, perhaps someone could look a this specific application and help me get started on the right path? I need to use a through-hole package if I can.
Thank you!
Currently I am using an IRL540 MOSFET. It works, but I don't know if it's the best for when the gate voltage decreases. I'd like to find the best MOSFET for my application. I keep thinking that I'll get the hang of the datasheet, but so far I am not getting very far. I am stuck at very basic questions, like "Does Gate-Source Voltage mean the voltage coming from the MCU, or is it that voltage minus the source voltage?" This question by itself probably shows my level of expertise. I tried searching for "MOSFET for dummies" but that didn't help much.
I am thinking that before I invest more time with the datasheets, perhaps someone could look a this specific application and help me get started on the right path? I need to use a through-hole package if I can.
Thank you!