Datasheet

Typical Single-Supply Applications (Continued)

Figure 23

dielectric absorption and leakage is minimized by using a polystyrene or polyethylene hold capacitor. The droop rate

is primarily determined by the value of C

and diode leakage current. The ultra-low input current of the LMC6484 has a negligible

effect on droop.

The LMC6484’s high CMRR (85 dB) allows excellent accuracy throughout the circuit’s rail-to-rail dynamic capture range.

The low pass filter circuit in

Figure 25

can be used as an anti-aliasing filter with the same voltage supply as the A/D converter.

Filter designs can also take advantage of the LMC6484 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 which take less board

space and cost less.

DS011714-37

FIGURE 23. Low Voltage Peak Detector with Rail-to-Rail Peak Capture Range

DS011714-38

FIGURE 24. Rail-to-Rail Sample and Hold

DS011714-27

FIGURE 25. Rail-to-Rail Single Supply Low Pass Filter

LMC6484