# BJT Transistors - On Characteristics

Concerning the technical documentation of the BC337 BJT NPN Transistor.

https://www.onsemi.com/pub/Collateral/BC337-D.PDF

I'm just learning the jargon. I am under the impression that in the 'on specifications' Vce = 1.0Vdc means the voltage from the collector to emitter pin cannot exceed 1.0V? Is that correct?

Thanks

• Please post a picture or retype formulas and relevant text from the datasheet, because if the destination of the link changes, your question will be mostly worthless for others. – Ariser Jan 28 '18 at 12:08
• Added some photos :-) – MangoHeat Jan 28 '18 at 20:28

No, If you look on the first page of that datasheet there will be a "Maximum Ratings" table. This has the maximum Vce voltage. The Vce = 1V specifies the conditions when the relevant parameters were measured.

It's showing the test conditions under which the measurement was made.

The characteristic you're referring to in that datasheet is for Vbe.

The datasheet states that Vbe can be up to a maximum of 1.2 V.

It says that the test conditions which pushed Vbe up to its maximum drop were conducting 300 mA of collector current, a current which caused a 1.0 V drop between the collector and emitter. Hence, conditions: Ic =300 mA, Vce = 1.0 V.

• Yup, that makes sense. Thanks for tying that together for me. – MangoHeat Jan 28 '18 at 20:33

It means (100mA case) that if you drive the transistor such that the Vce is 1.0V and the IC is 100mA, the required base current will reflect the stated hFE range.

Imagine an 11.0V supply voltage, a 10 ohm resistor to the collector, emitter grounded.

You apply increasing base current until you see Vce drop to exactly 1V.

Then hFE is Ic/Ib = 0.1A/Ib.

• AH this a lot of sense! Starting to see the relationship here. Thanks for your explanation. – MangoHeat Jan 28 '18 at 20:30