I'm trying to understand and tweak this smartplug reference design from TI. I'm stumped on the Metrology Analog Filters section on page 1. What I do not understand is why is there a 0R resistor on the Neutral line and why is this line grounded?
Also since the shunt method is inherently unsafe, can I simply replace the shunt with the primary of the current transformer? In the attached schematic the current source and the terminating resistor essentially mimic the secondary of a current transformer. If I can replace the shunt, can I simply do away with the instrumentation amp in the reference schematic and simply put the attached bit in and feed the signal to the MCU?
Also since the shunt method is inherently unsafe, can I simply replace the shunt with the primary of the current transformer? In the attached schematic the current source and the terminating resistor essentially mimic the secondary of a current transformer. If I can replace the shunt, can I simply do away with the instrumentation amp in the reference schematic and simply put the attached bit in and feed the signal to the MCU?
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