| ??? 11/29/06 14:44 Read: times |
#128669 - Parallel MOS transistors are fine Responding to: ???'s previous message |
I agree that bipolar devices should not be paralleled.
But it is perfetally safe to parallel MOS transistors. And most (all?) micros use MOS transistors. Most MOS output buffers consist of an array of paralled devices. In our chips, each NMOS output transistor can sink 2 mA. Our 24 mA buffer consists of 12 transistors in parallel. And when we need more, we parallel adjacent output buffers inside of the chip. Unlike bipolar devices, MOS transistors have a negative temperature coeffecient. As they get hot, they can carry less current. So, if a number of them are in parallel, and an individual transistor starts to carry too much current, then it heats up, and carries less current. Feedback is a wonderful thing. |
| Topic | Author | Date |
| Unknown pinouts application | 01/01/70 00:00 | |
| who can tell | 01/01/70 00:00 | |
| i did wonder why the ports were paralleled | 01/01/70 00:00 | |
| Serial Converter | 01/01/70 00:00 | |
| more information | 01/01/70 00:00 | |
| To... | 01/01/70 00:00 | |
| Yes but | 01/01/70 00:00 | |
| Hmm... | 01/01/70 00:00 | |
| What tells the scope? | 01/01/70 00:00 | |
| Nothing | 01/01/70 00:00 | |
| Level? | 01/01/70 00:00 | |
| What will happen | 01/01/70 00:00 | |
| Improper load? | 01/01/70 00:00 | |
| Jez see this | 01/01/70 00:00 | |
| Hhm, but this paralleling is widely used! | 01/01/70 00:00 | |
| Parallel MOS transistors are fine | 01/01/70 00:00 | |
| Perfectly safe? | 01/01/70 00:00 | |
| Reasonably safe | 01/01/70 00:00 | |
| What is this circuit intended to do, Ralph? | 01/01/70 00:00 | |
| What's it to do | 01/01/70 00:00 | |
What it does | 01/01/70 00:00 | |
| Just out of interest lynn, | 01/01/70 00:00 | |
| FPGA conversion cost | 01/01/70 00:00 |