SNOS674G November 1997 – April 2020 LMC6482
The circuit in Figure 69 uses a single supply to half-wave rectify a sinusoid centered about ground. RI limits current into the amplifier caused by the input voltage exceeding the supply voltage. Full-wave rectification is provided by the circuit in Figure 71.
In Figure 75 dielectric absorption and leakage is minimized by using a polystyrene or polyethylene hold capacitor. The droop rate is primarily determined by the value of CH and diode leakage current. The ultra-low input current of the LMC6482 has a negligible effect on droop.
The high CMRR (82 dB) of the LMC6482 allows excellent accuracy throughout the rail-to-rail dynamic capture range of the circuit.
The low-pass filter circuit in Figure 77 can be used as an antialiasing filter with the same voltage supply as the A/D converter.
Filter designs can also take advantage of the LMC6482 ultra-low input current. The ultra-low input current yields negligible offset error even when large value resistors are used. This in turn allows the use of smaller valued capacitors that take less board space and cost less.