APPLICATION INFORMATION

Volume Control Concept

Traditional electronic volume control circuits use a

multiplier technique with all the disadvantages of

high noise and distortion.

The used concept, as shown in Fig. 15 with digital

switched resistor dividers, provides extremely low

noise and distortion. The multiplexing of the resis-

tive dividers is realized with a multiple-input op-

erational amplifier.

Bass and Treble Control

The principle operation of the bass control is

shown in Fig. 16. The external filter together with

the internal buffer allows a flexible filter design ac-

cording to the different requirements in car radios.

The function of the treble is similar to the bass.

A typical curve is shown in Fig.19.

Outputs

A special class-A output amplifier with a modu-

lated sink current provides low distortion and

ground compatibility with low current consump-

tion.

Figure 15: Volume Control

Figure 16: Bass Control

Figure 17: Quiescent Current vs. Supply Voltage

Figure 18: Quiescent Current vs. Temperature

TDA7300

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