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Pete Semig is an analog-electronics engineer and technical author associated with Texas Instruments. A2013 company reference design identifies his applications work on difference and instrumentation amplifiers. The same document credits Peter Semig on its title page and uses Pete Semig in its author biography.^[ref]

His current-measurement work connects a small electrical signal to an instrument's usable range. A shunt resistor produces an electric potential difference proportional to current, and an amplifier makes that difference easier to measure. The2013 reference describes a single-supply low-side current sensing design for a stated10microampere-to10milliampere range.^[ref]

For an original simplified example, choose a1ohm shunt and current $I=20\mathrm{mA}$. The shunt drop is $V=IR=20\mathrm{mV}$, and a voltage gain of50 gives a1volt output. The shunt also dissipatesThus the measurement element changes the circuit it measures, through both its voltage drop and its dissipation. An input-equivalent amplifier offset of100microvolts would correspond to0.1milliampere in this example. These selected values do not reproduce the reference design.

Semig's Integrator Circuit by Pete Semig similarly states the operating limits behind an integrating amplifier: capacitor feedback gives an ideal integral, while offsets, finite bandwidth and the DC feedback path limit practical behavior.^[ref] His technical contribution is to connect circuit equations with component choices and the conditions under which a measurement remains interpretable.

A shunt resistor is a resistor used to establish a known relation between current and a measured electric potential difference. For current sensing, it is placed in the measured current path, and Ohm's law givesThe voltage-sensing circuit should draw negligible extra current for this simple relation to describe the desired branch current. Its small series voltage drop is often called the burden voltage.

An original example uses $R_s=10\mathrm{m\Omega }$ and $I=5\mathrm{A}$. The sensed drop is50millivolts and Joule heating dissipatesReducing resistance lowers both the burden and dissipation, but also reduces signal relative to a fixed amplifier offset or readout noise. The nominal resistor value alone therefore does not determine measurement quality.

Lead and contact resistance can dominate a low-value shunt. If a10milliohm shunt is inadvertently measured together with2milliohms of current-carrying interconnect, interpreting the total voltage using only the nominal shunt value overestimates current by20percent. Four-terminal sensing separates the high-current connections from the voltage-sense connections. Analog Devices' LTC6115 data sheet illustrates these Kelvin sense paths and explains how interconnect resistance introduces error.^[ref]

A practical characterization drives known currents through the shunt while measuring the voltage at its sense terminals, then repeats after thermal settling. Temperature coefficient of resistance, self-heating and connection geometry affect the realized conversion. The amplifier's operating range and measurement calibration must be assessed alongside the resistor.

A shunt converts current into a local voltage signal; it does not inherently provide electrical isolation between the measured circuit and its readout. High-side current sensing and low-side current sensing describe alternative placements of that measurement relative to the load and reference conductor.