CLC5801IM datasheet(11/14 Pages) NSC

11 / 14 page

Application Information (Continued)

Low Noise Integrator

The Circuit in

Figure 10 implements a deBoo integrator. Inte-

gration linearity is maintained through positive feedback. The

CLC5801’s low input offset voltage and matched inputs al-

lowing bias current cancellation provide for very precise inte-

gration. Stability is maintained through the constraint on the

circuit elements.

High-Gain Sallen-Key Active Filters

The CLC5801 is well suited for high-gain Sallen-key type of

active filters.

Figure 11 shows the 2nd order Sallen-Key low

pass filter topology. Using component predistortion methods

as discussed in OA-21 enables the proper selection of com-

ponents for these high-frequency filters.

Low Noise Magnetic Media Equalizer

The circuit in

Figure 12 implements a high-performance

low-noise equalizer for such applications as magnetic tape

channels. The circuit combines an integrator with a band-

pass filter to produce the low-noise equalization.

The circuit’s simulated frequency response is illustrated in

Figure 13.

DS101307-39

FIGURE 9. Transimpedance Amplifier Noise Model

DS101307-40

FIGURE 10. Low Noise Integrator

DS101307-41

FIGURE 11. Sallen-Key Active Filter Topology

DS101307-42

FIGURE 12. Low Noise Magnetic Media Equalizer

CLC5801IM Datasheet(PDF) 11 Page - National Semiconductor (TI)