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STLC1512

4.4 Amplifier Performance Specification

The two amplifiers on the STLC1512 are identical. One of them is used for the second order active low pass

filter that follows the PGA in the receive path. The other is an undedicated opamp that can be used either in the

transmit or receive paths.

The LPF amplifier is powered from the RXVCC supply and is therefore intended to be used in the receive path.

It has its positive terminal tied to the receive AC ground (RXANG) on chip.

The undedicated op amp is powered from TXVCC. It is intended for use in the transmit path but could be used

in the receive path. Using it in the receive path may cause receive noise to be coupled into the transmit path.

There should not be an issue with transmit noise coupling into the receive path in either configuration.

Figure 4. Power Supply Rejection of the PGA

1

<1>These curves represent typical performance. 6dB of margin is required for worst case.

dB