Figure 6-1: Preferred circuit arrangement for npn transistors
This circuit arrangement (Figure 6-1) is suitable for measuring most npn bipolar transistors. Shielding with no ground loops has been implemented. Ferrite rings on leads are recommended to suppress undesired oscillations.
In this example a heating-up transient of a medium power bipolar npn transistor will be measured. The software provides graphical help at the configuration selection to establish the proper connections between the T3Ster Main System Unit and the transistor under test (Figure 6-2).
Power steps can be large, it is useful to make trial measurements with limited voltage and current values for checking the measurement setup and in order to make estimations on the expectable temperature changes and on measurement range settings required. The measurement can be implemented as described in Table 6-1.
Figure 6-2: Help window in the measurement control software (npn bipolar transistor
measurement)