TS4604

Application information

Doc ID 17913 Rev 1

19/31

These capacitors must be placed as close as possible to the TS4604 to minimize parasitic

inductance and resistance that have a negative impact on the audio performance.

6.5

Input coupling capacitor (Cin)

An input coupling capacitor (Cin) might be used for TS4604 operation to block any DC

component of the audio signal.

Cin starts to have an effect in the low frequency region. Cin forms with Rin a high-pass filter

with a -3 dB cut-off frequency.

Example

A differential input gain as shown in Figure 46 on page 20 with the gain equalling 0 dB

(Rin = 10 k

Ω, Rfd = 10 kΩ) and an input capacitor of 2.2 µF gives:

The high-pass filter has a -3 dB cut-off frequency at 7.2 Hz in this case.

6.6

Range of the gain setting resistors

The TS4604 can be use in different configurations, as shown in figures 46, 47 and 48.

The gain is given by the external resistors Rfd divided by Rin. The feedback resistor Rfd

does not exceed 100 k

Ω for closed-loop stability reasons.

Table 7 gives the recommended resistor values and the gain for different types of

application.

Fc

3dB

–

()

1

2.

π Rin Cin

⋅⋅

------------------------------------------ Hz

()

=

Fc

1

2.

π 10000 2.2e10

6

–

⋅⋅

----------------------------------------------------------------

7.2Hz

==

Table 7.

Recommended resistors values

Rin

Rfd

Differential gain

Inverting gain

Non-inverting gain

10 k

Ω

10 k

Ω

0 dB

0 dB

6 dB

10 k

Ω

20 k

Ω

6 dB

6 dB

10 dB

10 k

Ω

50 k

Ω

14 dB

14 dB

16 dB

4.7 k

Ω

47 k

Ω

20 dB

20 dB

21 dB

10 k

Ω

100 k

Ω

20 dB

20 dB

21 dB