How does this power measurement(?) circuit work?

Thread Starter

austin944

Joined Mar 25, 2023
9
I have this circuit that appears to support measuring the voltage applied to a silicon chip. One of the purposes of the evaluation development board where this circuit appears is to support the measurement of the power consumption of a silicon chip. See circuit schematic in my reply post.

The two << connections on the left are connected to an external board connector. The names of these connections are SENSE+ and SENSE-, which suggests to me they're used to precisely measure the voltage across the chip's VDD and Ground using test equipment.

I don't understand the components being used and how the circuit is intended to work (e.g. does it make the voltage measurement more precise?). Pins 1 and 3 of C298 are connected to the VDD power supply of a silicon chip. Is C298 a feedthrough capacitor? What are XW7 and XW8?

There is also a 0.1 ohm shunt resistor elsewhere in the circuit to support power measurement of the same silicon chip, which I understand. The shunt resistor is connected between the chip's VDD and the external power supply.
View attachment 322723 <= if attachment doesn't work, see my post below

I can't post the entire circuit diagram or signal names since it's company confidential information. I work more in the field of digital chip validation and don't have much experience in power measurement.
 
Last edited:

Pyrex

Joined Feb 16, 2022
310
Hi,
I doubt you will get an adequate answer.
The schematic fragment you show is way too small. No information what kind of chip is to be tested- analog, digital, etc.
The term " a silicon chip " means nothing
 

Thread Starter

austin944

Joined Mar 25, 2023
9
It's a digital silicon chip connected to VDD and Ground. I can see nothing else connected to this circuit segment.
I think XW means cross-wire according to this Reddit post.
Still trying to understand the purpose of the circuit.
 

ronsimpson

Joined Oct 7, 2019
3,223
C298 looks like a feedthrough capacitor. But they are not used like that. There may be an error in the schematic.
Do you have pictures?
 
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