physics of bipolar transistors - notes and equations
Post on 13-Dec-2015
215 Views
Preview:
DESCRIPTION
TRANSCRIPT
Two transistors drawing from the same current.
Chain of dependencies
,
Collector current by
Now small changes in Vce Results in no changes between terminals so the same model as 4.22 is used. Also changes in Vcb creates no changes.
Eq 4.9 now with the early effect
Differentiation of eq. 4.67 with respect to Vce yields slope
Large signal model changed to
For small signal model, controlled current source remains unchanged to gm is
Change in collector current with Δ Vce
Ro is the ouput resistance. Both that and rπ are inversely proportional to the bias current Ic
Summary of concepts studied thus far
Leads to a sharp rise in IB and fall in β
Eq 4.23-4.25 must be modified for pnp
Then to include the Early effect for pnp
Same as the npn model
top related