WM3100

Preliminary Technical Data

w

PTD, October 2010, Rev 2.0

8

Figure 3 Differential Line Input

OUTPUT SIGNAL PATH

The WM3100 provides two line output channels, which each support a peak output voltage of ±2.97V

The line outputs are ground-referenced, removing the requirement for DC-blocking capacitors.

The WM3100 provides an internal low-pass filter (LPF) on the output paths. It is also recommended

to connect an external analogue low pass filter to the output pins. This ensures that all out-of-band

noise is filtered, and improves the maximum load capacitance rating, as noted in the “Electrical

Characteristics”.

There are many suitable LPF architectures, but a simple RC filter is recommended, as illustrated in

Figure 4. The filter shown here has a -3dB cut-off frequency of approximately 105kHz, and a droop of

-0.15dB at 20kHz.

Figure 4 Line Output Low Pass Filter