| MOS |
BIPOLAR |
| Majority - carrier device |
Minority - carrier device |
| No charge - storage effects |
The Charge stored in the base and the collector |
| High switching speeds, less temperature sensitive than bipolar devices |
Low switching speed, the temperature sensitive |
| Drift current (fast process) |
Coursing together current missile (process) |
| Voltage Driven |
The Current Driven |
| Purely capacitive input impedance.No DC current is required |
Low input impedance.The DC current required |
| Simple drive circuitry |
Complex drive circuitry (resulting from high base current requirements) |
| Predominently negative temperature coefficient on hold |
Positive temperature coefficient of the collector current |
| No thermal runaway |
Thermal runaway |
| Devices can be paralleled with some precautions |
Devices always be simple paralleled because of VBEMatching the problems and the local current concentration |
| Less susceptible to second breakdown |
Susceptible to second breakdown |
| Square - the law I - V characteristics at low current.Linear I - V the features at high current |
An Exponential I - V characteristics |
| Greater linear operating and fewer harmonics |
More intermodulation and cross - modulation products |
| Low on - hold (Low saturation voltage) because of conductivity modulation of high resistivity drift region |
High on - hold the and therefore larger conduction loss |
| Drain current tapping proportional to the channel width |
The Collector current approximately proportional to emitter stripe length and area |
| Low transconductance |
High transconductance |
| High breakdown voltage as the result of a lightly doped region of a channel to drain blocking tapping junction |
High breakdown voltage as the result of a lightly doped region of a base collector blocking junction |
