Infineon IRLML5203PBF and Cree C3M0065090J
In the age of the IC, transistors usually are not considered particularily interesting. However, some MOSFETs stand in the center of attention – let us be your guide to some cool components.
Crees C3M0065090J is not particularily impressive from a purely technical point of view – its main secret, instead, lays in the land layout shown in figure 1.
Smart land layouts lead to reduced creepage current potential
Cree forgoes the dedicated drain pin, and instead exposes this part of the semiconductor crystal using the tab normally used as a heatsink. When combined with the rest of the circuit layout, a spacing of more than 7mm is achieved – this helps reduce creeping currents, which can be a problem at high voltages or in precision designs. CREE furthermore promises a Drain – Source Voltage of 900V, which also makes the part well-suited to “rectifier” type activities.
Better Be Mindful
Part number two is IR’s irlml5203pbf – a classic which has been on the market for some time, but keeps generating significant spikes of search interest. When first introduced, the idea of packing a full HEXFET module into a SOT23 module was considered odd.
By now, the concept established itself. This does not, however, mean that the parts are not recommended for new designs: the on-resistance values shown in the figure still are respectable.
If power is at a premium, reducing losses can help
IR recommends that parts such as the irlml5203pbf or its sister part irlml6402pbf should be used in PCMCIA cards and similarly space-constrained settings. One classic application would be “low drop diodes” and similar polarity protection – in this case, however, take care to not exceed reverse voltage limits.
Finally, allow us to point you at here and here in case you never thought of using a FET as a reverse polarity protection component. Their extremely low voltage drop makes them effective in “corner cases” such as an automotive cold crank; losing 0.7V can make a world of difference