I am using a transistor (MPSA42) as level converter 1.5V to 3.3V.
I would like to use a minimum base current from the 1.5V signal.
When working out the base resistor value I need to use the current gain hfe.
The data sheet has minimum Hfe (attached) in the Electrical characteristic table but with Vce of 10V.There is also a hfe graph to Ic.
I am not sure what current gain value I should use in the calculations of the collector (load) resistor and base resistor?
The Hfe value measured by my multimeter (cheap and not calibrated) is 100.
When using an NPN transistor as a switch what current gain values (from the data sheet) should be used to calculate the resistor values to ensure saturation?
Thanks
cages
I would like to use a minimum base current from the 1.5V signal.
When working out the base resistor value I need to use the current gain hfe.
The data sheet has minimum Hfe (attached) in the Electrical characteristic table but with Vce of 10V.There is also a hfe graph to Ic.
I am not sure what current gain value I should use in the calculations of the collector (load) resistor and base resistor?
The Hfe value measured by my multimeter (cheap and not calibrated) is 100.
When using an NPN transistor as a switch what current gain values (from the data sheet) should be used to calculate the resistor values to ensure saturation?
Thanks
cages
Attachments
-
881.8 KB Views: 151