The CLC5509 system dynamic range performance is enhanced by using the CLC5523 variable gain amplifier as a post amplifier.

See

Figure 4 below.

The signal gain range is divided between the CLC5509 preamplifier and the post amplifier to allow wider dynamic range and bet-

ter performance for high crest factor signals. There are two common ways the CLC5523 variable gain could be controlled. The

first,

Figure 5, uses a DAC to digitally increase the gain in discrete steps. The second Figure 6 uses an AGC loop to maintain the

maximum system input signal-to-noise. Refer to the CLC5523 data sheet applications for the implementation details.

DS101304-36

FIGURE 4. Low Noise Pre Amp with Variable Gain Amplifier Circuit

DS101304-34

FIGURE 5. V

DS101304-35

FIGURE 6. V

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