The THCAD2 is a frequency to voltage converter type A-D designed for high noise environments like plasma voltage monitoring for torch height controls. The THCAD2 has 2 settable input ranges, 5V full scale and 10V full scale to accommodate different plasma source dividers. When used for direct plasma voltage monitoring, the THCAD2 requires an external high voltage resistor or divider. The THCAD2 has a frequency output range of approximately 100 KHz to 1 MHz. This can be counted directly by our FPGA cards for conversion to voltage value. The frequency output can optionally be divided by 32, 64 or 128 if the output must be counted in software. Frequency and reference frequency outputs are available. Both outputs are differential for high noise immunity. The A-D has galvanically isolated inputs (2500V common mode isolation). The THCAD2 can withstand a 500V input overload indefinitely. Being a frequency to voltage type A-D, resolution is sample rate dependent and approximately 10 bits at a 1 KHz sample rate and 12 bits at a 250 Hz sample rate. Pluggable screw terminal blocks are provided for all connections. The THCAD2 has built in DIN rail mounting hardware.