Rbe comparison
Below I listed up a
few values which I measured for various dual and single transistors. The
procedure is to measure Vce (collector is open) while variing the base
current from a few hundered micro amps to about 5 miliamps. I used a set
of a few fixed resistors in the range from 1k to 15k for the base current.
The Rbe is the high current slope of the Vce vs Ib graph. As we see the
PNPs have generally poorer performance than their complementary counterparts.
This is due to the different carrier mobility in p-Si. Also one can see
the very poor performance of the CA3046. The figures suggest that one maybe
gets away with single transistors glued together. At least for less critical
applications. Finally I measured the difference in Vbe for the arrays (fixed
base current of about 100 microamps), the collector was open. I found that
all of the pairs were within one millivolt.
| Type |
2SC1583 |
BC548C |
CA3096
(NPN) |
CA3046 |
MAT04F |
2SC3381 |
BC558C |
2SA1349 |
CA3096
(PNP) |
BC560C |
Rbe
[ohms] |
1,17 |
0,63 |
3,83 |
5,61 |
0,65 |
1,23 |
1,21 |
3,15 |
3,99 |
1,02 |
| Beta (datasheet) |
260 measured |
n/a |
150-500 |
110 typ. |
425 typ. |
200-700 |
n/a |
200-700 |
40-250 |
n/a |
| Comments |
dual NPN |
single
NPN |
array
mixed |
array
NPN |
quad
NPN |
dual NPN |
single
PNP |
dual PNP |
array
mixed |
single
PNP |