Timeline for When using an open-drain output to drive an NPN transistor, can the base resistor be replaced by a pull-up?
Current License: CC BY-SA 4.0
3 events
| when toggle format | what | by | license | comment | |
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| Jan 23, 2021 at 16:44 | comment | added | D.A.S. | for a 150 Ohm Fan almost any BJT or FET switch will work and startup speed is limited by load capacitance inside fan | |
| Jan 23, 2021 at 16:37 | comment | added | Gil | It should work fine, the MOSFET has a VGS(th) of 1.1V therefore you must insure the gate goes well below that; 0.7 volts is fine. Also note a MOSFET is a voltage controlled device unlike a BJT which is current controlled. The concern with the MOSFET is that you turn it on reasonably fast the gate does not control the gain in an enhancement MOSFET. | |
| Jan 23, 2021 at 15:09 | history | answered | D.A.S. | CC BY-SA 4.0 |