I would like to ask, for NPN tube, does the leakage current ICEO refer to the flow from C to E or from E to C?

深圳小花

I would like to ask, for NPN tube, does the leakage current ICEO refer to the flow from C to E or from E to C? [Copy link]

 

邀请：@maychang   @chunyang   @damiaa   @huo_hu   @qwqwqw2088   @wsmysyn   @freebsder   @w494143467   参与回复

I would like to ask, for NPN tubes, does the leakage current ICEO refer to the flow from C to E or from E to C?

Another question is, I want to see what is the maximum current that can flow through the base. Which parameter should I check?

maychang

"For NPN tubes, does the leakage current ICEO refer to the flow from C to E or from E to C?"

When the NPN tube is working normally, the collector is positive to the emitter. Therefore, the leakage current must flow from the collector to the emitter of the NPN tube.

深圳小花

maychang published on 2021-3-10 14:37 "For NPN tubes, does the ICEO leakage current refer to the flow from C to E or from E to C?" When the NPN tube is working normally, the collector is...

Thank you very much. I have another question. I want to see what is the maximum current that can flow through the base. Which parameter should I check?

maychang

"Another question is, I want to see what the maximum current that can flow through the base is. Which parameter should I check?"

However, not all transistors list this parameter, and most manuals do not list the maximum base current.

maychang

Shenzhen Xiaohua published on 2021-3-10 14:43 Thank you very much. I have another question. I want to see what the maximum current that can flow through the base is. Which parameter should I check? ...

You are too impatient. It takes me at least two or three minutes to copy a picture. It also takes me several minutes to type two lines of text.

maychang

Usually, the current flowing into the device is marked as positive, and the current flowing out of the device is marked as negative. Therefore, the leakage current of the PNP tube is usually marked as a negative value in the manual. As shown in the following figure:

This is copied from the instruction manual of PNP tube PSS8550.

深圳小花

maychang posted on 2021-3-10 14:44 "Another question is, I want to see what the maximum current that can flow through the base is. Which parameter should I check? 】 But not all transistors...

Thank you very much. What is this PEAK BASE CURRENT? Why is it 1A?

深圳小花

Shenzhen Xiaohua published on 2021-3-10 16:13 Thank you very much. What is this PEAK BASE CURRENT? There is 1A?

PEAK BASE CURRENT, the peak current is actually 1A, my heavenly base current! ! ! ! ?

深圳小花

maychang posted on 2021-3-10 14:44 "Another question is, I want to see what the maximum current that can flow through the base is. Which parameter should I check? 】 But not all transistors...

Are Vcbo, Vceo and Vebo the reverse breakdown voltages? Why is br not added? Or is the Vceo voltage the voltage from c to e or from e to c?

maychang

Shenzhen Xiaohua published on 2021-3-10 16:20 May I ask if Vcbo Vceo Vebo are all reverse breakdown voltages? Why is br not added, and...

CBO, C is in front and B is in the back, it is the voltage from C to B.

CEO, C is in front, E is in the back, it is the voltage from C to E.

EBO, E in front, B in the back, is the voltage from E to B.

maychang

Shenzhen Xiaohua published on 2021-3-10 16:13 Thank you very much. What is this PEAK BASE CURRENT? There is 1A?

This transistor model is PSS8050, a very common low-power transistor. The peak value is 1A, which is not surprising. The base pulse current allowable value of a common low-power transistor is mostly 100 mA.

深圳小花

maychang published on 2021-3-10 17:28 CBO, C in front, B in the back, is the voltage from C to B. CEO, C in front, E in the back, is the voltage from C to E. EBO, E in front, B in the back, is the voltage from E to...

Thank you very much. What are these three voltages used for? Is it the reverse breakdown voltage?

chunyang

Shenzhen Xiaohua published on 2021-3-10 16:15 PEAK BASE CURRENT, peak current, it is 1A, my base current! ! ! ! ?

Note the word peak, it can only withstand 1A current for a short time.

chunyang

Shenzhen Xiaohua published on 2021-3-10 21:46 Thank you very much. What are these three voltages used for? Is it the reverse breakdown voltage?

You may want to check the full names corresponding to these abbreviations.

maychang

Shenzhen Xiaohua published on 2021-3-10 21:46 Thank you very much. What are these three voltages used for? Is it the reverse breakdown voltage?

The upper left corner is marked with LIMITING VALUES, which means limit (value). Obviously, it is the limit set by the manufacturer and it is not allowed to exceed. If it exceeds, the manufacturer will not guarantee it.

深圳小花

maychang published on 2021-3-10 14:37 "For NPN tubes, does the ICEO leakage current refer to the flow from C to E or from E to C?" When the NPN tube is working normally, the collector is...

Thank you very much. You said that the leakage current flows from C to E. Please see the red arrow in the figure below. Why is -25V added? Iceo is also -100nA? Negative 100nA, this current flows from the emitter electrode to the collector electrode? According to your statement, the current should be measured when CE is added with +25V. Why is the current measured here when -25V is added?

maychang

Shenzhen Xiaohua published on 2021-3-11 13:19 Thank you very much. You said that the leakage current flows from C to E. Please see the red arrow in the figure below. Why...

"You said the leakage current flows from C to E. Please see the red arrow in the figure below. Why do we need to add -25V?"

The original reply has already explained: This is the datasheet of the PNP tube PSS8550. For a PNP tube, the collector is naturally negative to the emitter. The leakage current is also marked as a negative value, which means it flows out from the collector.

maychang

Shenzhen Xiaohua published on 2021-3-11 13:19 Thank you very much. You said that the leakage current flows from C to E. Please see the red arrow in the figure below. Why...

I also said in my reply to that post that inflows are usually marked as positive values and outflows are marked as negative values.

Not only did you not read the datasheet carefully, you also did not read the reply carefully.

深圳小花

maychang posted on 2021-3-11 14:28 I also said in my reply to that post that usually inflows are marked as positive values and outflows are marked as negative values. Not only did you not read the datasheet carefully, you also read the reply...

Thank you very much, super master, maychang.