Texas Instruments APA100 Instrukcja Użytkownika Pobierz pdf (Strona 40)

Gain and Phase Response

5-6

5.4 Gain and Phase Response

The APA100 is a closed−loop, class-D audio power amplifier with an LC output

filter. The output filter and the 39-kHz loop bandwidth limit the bandwidth of the

APA100 reference design. The gain versus frequency curve is shown in

Figure 5−8. The 4-Ω curve rolls off sooner than the 8-Ω curve.

Figure 5−8. APA100 Gain vs Frequency With 4-W and 8-W Load

20 100 200 1 k 2 k 10 k 20 k

Gain − dB

f − Frequency − Hz

4 

8 

5.5 Signal-to-Noise Ratio (SNR)

The APA100 has low noise and a wide output swing. The noise does not

increase with output power making the signal-to-noise ratio (SNR) just before

clipping good for this type of amplifier. The noise was measured with an

A-weighted filter to be 350 µV rms. The amplifier can output 19 Vrms. This

makes the SNR 95 dB at 19-Vrms output.

1 2 ... 35 36 37 38 39 40 41 42

Brak uwag

Texas Instruments APA100 Instrukcja Użytkownika Strona 40