| ??? 08/22/06 12:07 Read: times |
#122764 - ...are you? Responding to: ???'s previous message |
Richard Erlacher said:
Granted, you can't drive a substantial load with a 5-volt MCU either. However, you CAN drive a logic MOSFET and IT can drive the load. With 3-volt logic you have to drive a driver and only then have you enough voltage to drive a low-cost MOSFET. Wow, first solenoids, now logic FETs. Well theres a lot to debate about them as well. In the end it is APPLICATION DEPENDENT. If you use the FET as a simple switch, okay, then it might even have a low enough Rdson driven from a 3,3V powered device. As soon as you do fast switching your 5V MCU will probably lack the juice to drive the gate capacitance. Richard Erlacher said:
The FPGA's have their place, and are very much at home in portable and other low-voltage applications that don't require lots of power. Of course, what I think is practical isn't going to change what the FPGA mfg's think is easy and profitable. In the meantime we'll just have to wait until there are more low-voltage logic MOSFETs, which will cause their prices to drop. Portable devices are not yet a big market for FPGA's. Power consumption is probably the major issue, thats where MCUs shine. There are other criterias than the types of MOSFETs available that decide whether or not to pick a FPGA over a MCU. It's project/application dependent. I say it's nonsense that 5V compatibility has anything to do with that. Cheers, Roger |
