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I have to measure the current flowing inside a SoC through a multimeter. In the board schematics, I found that the SoC provides a structure to measure the current:

Now, I should connect them with a shorting jumper, but the headers don't have built-in pins. Should I have to solder the pins or is there a more lightweight solution that permits me to avoid soldering?

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    \$\begingroup\$ A bit about your wording: "current inside a SoC" isn't what you're measuring, it's "current into a SoC". \$\endgroup\$ – Marcus Müller May 28 '18 at 16:27
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You should remove R117 and connect the DMM in series with the SoC, that is, positive to pin 1 of J15, Negative to pin 2. The schematic doesn't tell us anything about the mechanical connection. It is very likely that you will have to solder wires, somewhere.

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The header J15 in your schematic snippet is labeled with DNP. That means "do not populate" which was put there for production purposes to save cost.

To use this current measuring header you have two choices. Both would include soldering in a two pin header at J15 so you can easily connect up a measuring device to the circuit. After measurements are completed you can simply put a shunt plug on the header to avoid further soldering on your board.

Method 1 - You would remove R117 zero ohm resistor completely and leave that site open. Then you would attach a meter in current measuring mode between the two pins of the header. The meter would read out the current directly. The typical DMMs in use today can measure either polarity so you get by if you mistakenly do not connect the (+) lead of pin 1 and (-) lead to pin 2.

Method 2 - You would remove R117 and replace it with low ohms valued accurate resistor. You could start with a 1% 0.1omm resistor. Then you connect the measuring device in voltage mode to the header pins 1 and 2. The meter will read the voltage drop across the new resistor. If a 0.1ohm was used you would read 1mV for each 10mA of current drawn by the SoC. If a 1ohm resistor was used then you would read 10mV for each 10mA of current taken by the SOC.

(Note that for Method 2 you can avoid excessive soldering in your circuit board and incorporate the current shunt measuring resistor into the wiring that you attach to the J15 header).

With these methods you do have to be careful to not have too much series resistance between the power supply and the SOC (whether that be the current shunt resistance in the meter for case 1 or the added resistor for case 2). If the resistance gets too high then the SOC drawn current will cause a voltage drop and thus the SOC could be operating outside its spec range of operation. This behavior would likely give an inaccurate picture of what the SOC's normal operating current actually is.

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