The following are closeup shots of the two boards. The authentic board has a B0 RP2040, the clone has a B2 RP2040.
The power chip on the clone board is marked 'G3P'. This is an AP2112, a 600 mA LDO regulator. It has an EN pin, which I presume allows it to work with 3V3_EN so that should work. Searching Google, I did not find AP2112 mentioned together with proper RPi Pico boards, but it turned up in a Sparkfun board:
https://www.sparkfun.com/products/18288
So you can run most loads with this AP2112 LDO, but you do not have the boost feature. Use it with USB and it will work fine, but if you plan to use 2 x NiMH batteries for your project then you might just get a rude surprise.
The inductor is NOT connected to the LDO. The traces from the LDO do not join up with the inductor's pads -- it's not easy to see it (I'd need one of those PCB microscopes if I squint some more at the boards, and loupes are not fun), but I have checked it with a multimeter. The inductor is about 0.2 ohm, the authentic Pico's inductor is 0.1 ohm so it might be a real inductor picked for its similarity to a RPi Pico's inductor.
So the inductor is for pretend -- they want to pretend that it is like an authentic Pico -- an exact work-alike clone. Except it isn't exact. This one has an LDO and can't boost. Dodgy.
The clone's diode, marked as 'S1', is probably a Schottky of the 1N5817W type with the same sod-123 package as the diode in an authentic board. The MBR120VLSF on the authentic Pico dropped 0.19V with a blinking program; the 'S1' diode dropped 0.28V. An older Schottky, but at least it is a reasonably good performer. Old 1N5817 datasheets have better charts, and the forward drop is about in the 1N5817 ballpark. This type of diode is made by many companies so it would be impossible to tell exactly whose diode it is.
So the clone should work fine if you use it in buck (cough)... LDO mode. The output of the AP2112 was measured at 3.31V on this clone board while on USB power. I hope it's an actual AP2112... Plugging 3.34V at VBUS gives 3.06V at VSYS with the blinking program running, and at the 3V3 pin it becomes 3.03V, the Vout of the AP2112 LDO tracking Vin.
I've only tried blinking but I do not expect to have any issues with the RP2040 on the clone board. I can make use of it, as long as it's not the DC-DC boost feature that I want.![:D]( "Very Happy")
A couple more pictures follows.
https://www.sparkfun.com/products/18288
So you can run most loads with this AP2112 LDO, but you do not have the boost feature. Use it with USB and it will work fine, but if you plan to use 2 x NiMH batteries for your project then you might just get a rude surprise.
The inductor is NOT connected to the LDO. The traces from the LDO do not join up with the inductor's pads -- it's not easy to see it (I'd need one of those PCB microscopes if I squint some more at the boards, and loupes are not fun), but I have checked it with a multimeter. The inductor is about 0.2 ohm, the authentic Pico's inductor is 0.1 ohm so it might be a real inductor picked for its similarity to a RPi Pico's inductor.
So the inductor is for pretend -- they want to pretend that it is like an authentic Pico -- an exact work-alike clone. Except it isn't exact. This one has an LDO and can't boost. Dodgy.
The clone's diode, marked as 'S1', is probably a Schottky of the 1N5817W type with the same sod-123 package as the diode in an authentic board. The MBR120VLSF on the authentic Pico dropped 0.19V with a blinking program; the 'S1' diode dropped 0.28V. An older Schottky, but at least it is a reasonably good performer. Old 1N5817 datasheets have better charts, and the forward drop is about in the 1N5817 ballpark. This type of diode is made by many companies so it would be impossible to tell exactly whose diode it is.
So the clone should work fine if you use it in buck (cough)... LDO mode. The output of the AP2112 was measured at 3.31V on this clone board while on USB power. I hope it's an actual AP2112... Plugging 3.34V at VBUS gives 3.06V at VSYS with the blinking program running, and at the 3V3 pin it becomes 3.03V, the Vout of the AP2112 LDO tracking Vin.
I've only tried blinking but I do not expect to have any issues with the RP2040 on the clone board. I can make use of it, as long as it's not the DC-DC boost feature that I want.
A couple more pictures follows.
Statistics: Posted by katak255 — Sun Nov 17, 2024 7:11 am