Other Parts Discussed in Thread: LM3480, TIDA-00914
Hi Ti ,
In the circuit diagram of TIDA-00914, when the AMC1306 is used for current sensing, an LDO(LM3480) is employed between AVDD and AGND to serve as the power source for the floating terminal. However, the voltage at the floating point is equal to the VDS (drain-to-source voltage) of the lower-side MOSFET. In a system with a voltage of 200V, this means there will be a minimum floating voltage of 200V. You might wonder why a standard LDO can be used in this scenario, especially since LDO datasheets typically do not specify restrictions on the floating voltage at the GND pin. I would like to inquire about the principles behind why this setup doesn't encounter issues.
The second question I would like to inquire about is whether, if we do not consider the impact of resistor-related power, choosing the +/-250mV variant of the AMC1306 would result in better noise immunity compared to the +/-50mV variant.
Thanks,
JJ
