Hi, I am using the attached circuit using the p-mosfet below to switch power to my circuit, and I am getting strange results.
http://www.onsemi.com/pub_link/Collateral/MMBF2202PT1-D.PDF
My Vin is 3.2 V, and the on/off to the gate is 2.5 V / 0V (gnd). I need to periodically source this voltage and about 8-10 mA to my load for 10 seconds every 5 minutes. If I use a power supply, my circuit works just fine, however when I use a 3.0 V coin cell battery (CR2032, about 3.2 V actually) the circuit does not perform correctly. I know it is not a current supplying issue from the battery because when I directly connect the battery to the circuit everything works fine. Also, I am not losing any voltage drop through the mosfet, the voltage delivered to the load is equal to the source voltage when the gate is off.
If I put two 3V batteries in series to get 6V at the drain, it works. My question is why doesn't it work with a single 3V battery through the FET when I have tested that 3V is fine with a power supply through the FET and directly using a battery?
Can anyone give me some insight on what could be happening here?
http://www.onsemi.com/pub_link/Collateral/MMBF2202PT1-D.PDF
My Vin is 3.2 V, and the on/off to the gate is 2.5 V / 0V (gnd). I need to periodically source this voltage and about 8-10 mA to my load for 10 seconds every 5 minutes. If I use a power supply, my circuit works just fine, however when I use a 3.0 V coin cell battery (CR2032, about 3.2 V actually) the circuit does not perform correctly. I know it is not a current supplying issue from the battery because when I directly connect the battery to the circuit everything works fine. Also, I am not losing any voltage drop through the mosfet, the voltage delivered to the load is equal to the source voltage when the gate is off.
If I put two 3V batteries in series to get 6V at the drain, it works. My question is why doesn't it work with a single 3V battery through the FET when I have tested that 3V is fine with a power supply through the FET and directly using a battery?
Can anyone give me some insight on what could be happening here?
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