We're working on a power supply unit for ionic pumps. My supply voltage is 2kV to 3kV with current varying from 0.5mA to 1mA. We wanted to add a high side current measurement indication in these units-an analog voltage (like 5V for 0.5mA). First part of the circuit is sensing the current and in our research we came across the ACS product line, particularly speaking of ACS722KMATR-10AB datasheet attached here it offers Isolation for 4800 Vrms. For amplification we were thinking of using ADA4528, MAX4238 and AD8428. We want to know a few things:
A. Is the term Isolation Voltage in any way related to the Voltage Rating of the sense resistor of ACS722KMA? If not then what is the Voltage Rating of the sense resistor?
B. The Basic Isolation Working Voltage for ACS722KMA is stated 1097 Vrms in the datasheet, there is a little confusion if ACS722KMA be able to survive constant 2kVDC to 3kVDC ?
C. I came across another article, The schematic attached in this EEVBlog suggests another simpler method of measurement but unfortunately I wasn't able to find current sense resistors with High Voltage Rating.
How can I measure 1mA from a 2kV source?