Logic-level MOSFET suggestions
Logic-level MOSFET suggestions
(OP)
I'm currently designing with the Fairchild FDS6614A (N-channel) in an SO-8 package, but I'm interested in any suggestions/favorites from everyone. This is for fairly low currents (<<1A/chip).
I came across a handful of logic-level FETs in my search (TI, Fairchild, Panasonic(?), among others), but didn't find nearly as many as I expected. Maybe I'm typing in the wrong thing into Google ("logic level FET").
I would love to find something in a smaller package (need to stuff 30+ of these on a small board), say an SOT-23? Power dissipation would be significantly less than 10mW per package.
I came across a handful of logic-level FETs in my search (TI, Fairchild, Panasonic(?), among others), but didn't find nearly as many as I expected. Maybe I'm typing in the wrong thing into Google ("logic level FET").
I would love to find something in a smaller package (need to stuff 30+ of these on a small board), say an SOT-23? Power dissipation would be significantly less than 10mW per package.





RE: Logic-level MOSFET suggestions
TI has a line of driver arrays that are quite powerful.
RE: Logic-level MOSFET suggestions
I went to the Digikey site, and tried a few sorts. It appears Fairchild is good at listing their parts as logic level compatiable.
I don't really have a favorite. Last two projects I used a Fairchild Si4410DY (SO-8) just because it showed-up in the example circuit, and a BSS84 (ON Semi) for a small signal application because we had them in use from a previous project.
RE: Logic-level MOSFET suggestions
RE: Logic-level MOSFET suggestions
RE: Logic-level MOSFET suggestions
<nbucska@pcperipherals DOT com> subj: eng-tips
RE: Logic-level MOSFET suggestions
I once had a logic MOSFET (don't remember the number, but about 50V, 3A) being driven from a Zilog Z8 micro (4 MHz clock) through a 1K resistor to the gate. Solid ground-plane, proper bypassing, etc. MOSFET was hooked to a inductive load with about 350 ohms of resistance to 12 Volts. Mosfet was being PWM controlled at about 150 Hz
Went to the test lab to do emissions, and had a 4 MHz picket fence up through 30 MHz. Removed the load from the MOSFET - still had the same picket fence. Changed the series gate resistor to 10K and the picket fence went away! the PWM had slight risetime then, but it was OK. The micro didn't like driving the capacitive gate of the MOSFET, even through a 1K resistor.
Just goes to show you that driving a MOSFET directly from a micro is never straight forward, though this was more of a micro problem.
RE: Logic-level MOSFET suggestions