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In the circuit below, due to the base voltage, the circuit becomes a common-emitter setup. However, assuming a reasonable value for the base current the BJT should be in saturation.

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However the value given for β is a βmin value (βmin = 30), which only holds for active forward mode. I attempted to calculate the βforced value by assuming an Isc/Is value of 100, which yielded βforced = 14.45. However using this value with KVL from B to E gives 10 - 10000ib - 0.7 - 1000(βforced + 1)ib = 0 yields an ib value of 0.365 mA and an ic value of 5.3 mA, which is different from the value of ic given in the book (4.35 mA).

What am I doing wrong here? It seems like it should be a straightforward question but I must be doing something wrong.

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1 Answer 1

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You are overthinking this.

The emitter current is 4.8mA using your 200mV drop for a transistor in saturation. The emitter voltage is 4.8V.

The base current is (10V-(4.8V+0.7V))/10K = 450uA

The sum of all three currents flowing into the transistor must be ??

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