TPA2001D1

1-W FILTERLESS MONO CLASS-D AUDIO POWER AMPLIFIER

SLOS338D – SEPTEMBER 2000 – REVISED DECEMBER 2002

8

POST OFFICE BOX 655303

APPLICATION INFORMATION

Table 1. Gain Settings

GAIN1

GAIN0

AMPLIFIER GAIN

(dB)

INPUT IMPEDANCE

(k

Ω)

GAIN1

GAIN0

TYP

TYP

0

0

6

104

0

1

12

74

1

0

18

44

1

1

23.5

24

input resistance

Each gain setting is achieved by varying the input resistance of the amplifier, which can range from its smallest

value to over six times that value. As a result, if a single capacitor is used in the input high-pass filter, the –3dB

or cutoff frequency also changes by over six times.

Ci

IN

ZI

ZF

Input

Signal

The –3 dB frequency can be calculated using equation 4.

(4)

1

2

p Z

I

C

i

high-pass filter with the corner frequency determined in equation 5.

1

2

pZ

I

C

i

–3 dB

fc

(5)