@@misterhat5823 well not everything is obvious in the moment. he asks for help - I think that is a measure of self awareness that allows other people to contribute. and he makes a lot of videos. perhaps that push to produce sometimes manifests as missing the obvious.
you can see a charge pump, which you would not need if the fets were P-type. You need the charge pump as with N-types you need to pull the gate higher than the Source or Drain as when the fet is turned on the source and drain are at about the same voltage e.g the input voltage. the charge pump give it the extra 10 or so volts above the input voltage to drive the gates hard on. N-channels normally provide low Rds(on) than p-channels
@@misterhat5823 well everybody is allowed a few mistakes. And clearly without the charge pump it would not work :-) if you can live with a higher Rds(on) then P-channel fets are easer to drive as a high side switch.
I bet this chip was for USB power. 500mA per channel at 5V per port? That's the old USB power spec right there - 5V 500mA 2.5W. Obsoleted because few devices are doing it. But I'm sure you can find tons of replacement parts for it, because tons of manufacturers would have produced parts for USB power control. The overcurrent pins are open drain to allow for wiring them all together to a CPU interrupt in case the USB device drew too much current.
Doesn't appear to be a P-channel to me. Looks like an N-channel with a charge pump. Since I have a ton of them, I do this with 555s or 4000 series inverters all the time.
0.3v drop because that's enough for the N-channel to turn on. Datasheet shows you need a charge pump as they are N-channels inside, not P-channel. Why do you pretend you didn't see it?
Measure at the chip pins rather than the breadboard.
good possibility,...
First thing I thought of too - those solderless breadboards are notorious for having poor contacts.
For a fellow who seems quite knowledgeable he seems to miss the obvious a lot.
@@misterhat5823 well not everything is obvious in the moment. he asks for help - I think that is a measure of self awareness that allows other people to contribute. and he makes a lot of videos. perhaps that push to produce sometimes manifests as missing the obvious.
you can see a charge pump, which you would not need if the fets were P-type. You need the charge pump as with N-types you need to pull the gate higher than the Source or Drain as when the fet is turned on the source and drain are at about the same voltage e.g the input voltage. the charge pump give it the extra 10 or so volts above the input voltage to drive the gates hard on. N-channels normally provide low Rds(on) than p-channels
Even without a charge pump, that's clearly an N channel symbol.
@@misterhat5823 well everybody is allowed a few mistakes. And clearly without the charge pump it would not work :-)
if you can live with a higher Rds(on) then P-channel fets are easer to drive as a high side switch.
@@TheEmbeddedHobbyist Of course he's allowed to make mistakes.
@@misterhat5823 Every time I post a video, I expect I've made a slip up or two. it's even better if no one notices 🙂
Maybe contact resistance in the protoboard. Try probing directly at the IC.
Bottom of the first page of the datasheet says "refer to STMPS2242MTR", digikey also suggests the STMPS2252MTR.
Poor contacts on breadboard.On input you have 5V and at output 4.76V but when measure voltage drop later you get 0.11V
Maybe 80 mΩ is just a MOSFET. But the microcircuit still contains a current sensor, which also has its own resistance.
The Data sheet says its an N-Channel MOSFET.
Hey, nice HP calc! I don't think I saw it on your channel before.
Cool chip.
0.5A at 80 to 100mohm is about 440mV. Maybe the drop is nonlinear and that's an equivalent resistance at rated current.
I have to agree with others here .. almost 100% sure the extra 360 mOhms is from bad breadboard contacts.
Did you check the power supply droop (at the pins)? Some of this might not be the chip's fault...
Mouser has the modern replacement part in stock, STMPS2242MTR
I bet this chip was for USB power. 500mA per channel at 5V per port? That's the old USB power spec right there - 5V 500mA 2.5W. Obsoleted because few devices are doing it. But I'm sure you can find tons of replacement parts for it, because tons of manufacturers would have produced parts for USB power control. The overcurrent pins are open drain to allow for wiring them all together to a CPU interrupt in case the USB device drew too much current.
TPS2042A from TI is a good replacement I used it a lot is USB power circuit
Doesn't appear to be a P-channel to me. Looks like an N-channel with a charge pump. Since I have a ton of them, I do this with 555s or 4000 series inverters all the time.
Metal oxide semiconductor field effect transistor
loss thru the push button switch you're using... maybe?
2.5 ms rise time is a lot. You can find electromechanic miniature relais which have a delay of less than 1 ms.
kindly make a Ki CAD Tutorial Playlist. From simulation through Ng SPICE up to final prototype to PCBway
For beginners like me it would be greatly helpful to get into the world of electronics
0.3v drop because that's enough for the N-channel to turn on. Datasheet shows you need a charge pump as they are N-channels inside, not P-channel. Why do you pretend you didn't see it?