AliExpress SMD transistors tested

[DAJE]

I've bought some SMD trannies from AE recently, and decided to solder a few to adaptor boards and run them through my Peak Atlas DCA75.

4 x 2222
3 x J201
3 x 5457

Important note:
I don't know what these numbers mean. I had some $ to blow and I overestimated my ability to learn about numbers, so I bought a DCA75. Realistically, anything beyond basic primary/grade school maths is beyond my ken. I am not dumb, I'm just not smart in this particular area. So don't ask me to explain anything here: I do not know. I have copy/pasted the test notes from the DCA75 Windows software, perhaps reading them will answer any questions you have.

The test results are copy/pasted from the DCA software too, so there are no typos.

2222 A
NPN Silicon BJT
Red-C Green-E Blue-B
hFE=303 at Ic=5.11mA
Vbe=0.753V at Ib=5.00mA
VceSat=0.317V at Ic=5.0mA and Ib=0.90mA
IcLeak=0.000mA

2222 B
NPN Silicon BJT
Red-C Green-E Blue-B
hFE=271 at Ic=5.02mA
Vbe=0.752V at Ib=5.00mA
VceSat=0.018V at Ic=5.0mA and Ib=1.00mA
IcLeak=0.000mA

2222 C
NPN Silicon BJT
Red-C Green-E Blue-B
hFE=273 at Ic=5.00mA
Vbe=0.755V at Ib=5.00mA
VceSat=0.018V at Ic=5.0mA and Ib=1.00mA
IcLeak=0.000mA

2222 D
NPN Silicon BJT
Red-E Green-C Blue-B
hFE=173 at Ic=13.27mA
Vbe=0.751V at Ib=5.00mA
VceSat=0.016V at Ic=5.0mA and Ib=1.00mA
IcLeak=0.000mA

Current gain (hFE) can be measured between 4 and 32000.
Gain accuracy for gain lower than 2000 is typically ±3% ±5hFE.
Gain is determined by measuring the step change in base current required to obtain a step change of collector current of 5.0mA±0.25mA. This ensures that leakage current does not influence the gain figure.
Saturation Voltage VceSat is measured, with a collector current of 5mA and a base current of 1mA, if the hFE is greater than 10.
Base-emitter voltage drop is measured at a different base current to that used for the gain measurement.
Base-emitter voltage accuracy is typically ±1% ±0.006V at a current of typically 5.0mA ±1.0mA.
If the base-emitter voltage is less than 0.55V, then it is likely that the transistor is a germanium type.
Leakage current of germanium types can vary hugely with small temperature variations. Even the cooling after handling (or the warming during handling) can influence the leakage current very significantly. That is normal.
Gain of silicon and germanium types is influenced by temperature, particularly for higher gain devices.
Gain will vary considerably over different collector currents.

 

[DAJE]

J201 A
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.68V at Id=4.8µA
Vgs(on)=0.33V at Id=1.03mA
gfs=1.8mA/V at Id=0.6mA to 1.0mA
Idss=0.49mA at Vds=2.99V
Rds(on)=660.0Ω at Id=1.0mA and Vgs=0.0V

J201 B
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.71V at Id=5.4µA
Vgs(on)=0.32V at Id=1.08mA
gfs=1.8mA/V at Id=0.6mA to 1.1mA
Idss=0.53mA at Vds=3.00V
Rds(on)=654.3Ω at Id=1.1mA and Vgs=0.0

J201 C
N-Ch JFET
Red-G, Symmetrical Src/Drn
Vgs(off)=-0.67V at Id=4.9µA
Vgs(on)=0.34V at Id=1.03mA
gfs=1.8mA/V at Id=0.6mA to 1.0mA
Idss=0.47mA at Vds=2.99V
Rds(on)=665.7Ω at Id=1.0mA and Vgs=0.0V

5457 A
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.38V at Id=5.0µA
Vgs(on)=0.18V at Id=5.01mA
gfs=22.1mA/V at Id=3.0mA to 5.0mA
Idss=1.60mA at Vds=3.00V
Rds(on)=33.5Ω at Id=5.0mA and Vgs=0.0V

5457 B
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.39V at Id=4.9µA
Vgs(on)=0.17V at Id=5.01mA
gfs=21.4mA/V at Id=3.0mA to 5.0mA
Idss=1.73mA at Vds=3.01V
Rds(on)=33.5Ω at Id=5.0mA and Vgs=0.0V

5457 C
N-Ch JFET
Green-G, Symmetrical Src/Drn
Vgs(off)=-0.43V at Id=5.3µA
Vgs(on)=0.14V at Id=5.01mA
gfs=21.0mA/V at Id=3.0mA to 5.0mA
Idss=2.27mA at Vds=3.01V
Rds(on)=32.2Ω at Id=5.0mA and Vgs=0.0V

Many Junction FETs (JFETs) are manufactured with symmetrical drain and source structures. This means that the DCA Pro cannot detect any difference in characteristics between the drain and source.
If the DCA Pro has detected sufficient difference in characteristics between the drain and source then it will identify which colour test lead is connected to each of the drain and source.
The DCA Pro will identify the gate terminal for symmetrical and asymmetrical JFETs.
Pinch-off is determined when drain current is typically 5uA (4.0uA to 6.0uA).
Pinch-off accuracy is typically ±2% ±0.01V.
The gate “on” threshold is determined when drain current is 5.0mA ±0.25mA.
Gate threshold voltage accuracy is typically ±2% ±0.01V.
Transconductance is measured for a typical range of drain current from 3mA to 5mA.
Transconductance can vary significantly at different drain currents.
Transconductance accuracy is typically ±5% ±2mA/V for values less than 20mA/V.
Transconductance accuracy is typically ±10% ±5mA/V for values more than 20mA/V.
Normally-off JFETs are typically made of Silicon-Carbide and yield “pinch-off” and “on” gate thresholds of above zero volts (relative to the source terminal).
Idss is the drain-source current when the gate-source voltage is zero and the drain-source voltage is 3V. The Idss measurement is often used for the purpose of matching JFETs.
Rds(on) will be measured at the test conditions displayed. Measurement resolution for Rds(on) is typically <0.5Ω. Values less than 1.0Ω will be displayed as Rds(on)<1.0Ω.

 

[temol]

Vgs(off) and Idss for J201 looks ok, within specs.

But 5457...
Datasheet says -0.5V to -6.0V. From my experience it's mostly between -1.2V and -2.2V. Here, Vgs(off) seems to be way to low. Maybe out of specs factory rejects? Two years ago I bougt 20 MMBF5457 from Aliexpress, all with similar, very low Vgs(off).

 

[DAJE]

Vgs(off) and Idss for J201 looks ok, within specs.

But 5457...
Datasheet says -0.5V to -6.0V. From my experience it's mostly between -1.2V and -2.2V. Here, Vgs(off) seems to be way to low. Maybe out of specs factory rejects? Two years ago I bougt 20 MMBF5457 from Aliexpress, all with similar, very low Vgs(off).

I bought some through-hole 5457s that seemed to be out-of-spec a while ago, but they work where I tried them. Though of course that doesn't mean they'll work everywhere.

I haven't compared these ones to my other list of tested trannies, there are known good genuine ones on that list.

EDIT: Yes, the new 5457s are very similar to the "out-of-spec" through-hole ones, and the known good ones I have are in the same range you mention. They'll work as buffers or whatever anyway, I'm sure of that.

Interestingly, the MMBT2222As are closely matched with the through-hole 2N2222As I tested except they have higher gains.

 

[Feral Feline]

I've gotta order some SMD BJT for my MAS Picos and MAS Stomp Fuzz boards.

Where did you order from? BXV?

 

[DAJE]

MMBT2222A

https://www.aliexpress.com/item/1005002334131697.html

MMBFJ201

https://www.aliexpress.com/item/32693046067.html

MMBF5457

https://www.aliexpress.com/item/33018658213.html

​

 

[lrgaraujo]

Fun fact @temol and @DAJE : the 2n5457 spec'd in the build document for the Figment (migfet) are as out of spec as the ones DAJE has. They actually look like a very good match

 

[KR Sound]

I've gotta order some SMD BJT for my MAS Picos and MAS Stomp Fuzz boards.

Where did you order from? BXV?

What do you need? I have 100 each of MMBF- J201 and 5457

 

[Feral Feline]

What do you need? I have 100 each of MMBF- J201 and 5457

Thank you! I'm good for JFETs.
If I need more JFETs there's still some places I can order from that carry inventory.
Besides, you'll run out of those in no time, yourself, I'm sure.

The MAS Picos and Stomp Fuzz are BazzFuss, so take BJTs.

You have given me an idea, though... Escobedo and others experimented with JFET Fuzz Faces, so maybe I should put a JFET on the breadboard and see if I can make a JFET-based BazzFuss!

 

[KR Sound]

You have given me an idea, though... Escobedo and others experimented with JFET Fuzz Faces, so maybe I should put a JFET on the breadboard and see if I can make a JFET-based BazzFuss!

I was just reading about his jfet FFs last night. I say go for it!

The Many Faces of Fuzz

 

[lrgaraujo]

Btw, @Robert, I love that you're now including jfet measurements. It's so helpful when looking for a possible substitute