LM1972

SNAS094D – APRIL 1995 – REVISED MARCH 2013

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APPLICATION INFORMATION

ATTENUATION STEP SCHEME

The fundamental attenuation step scheme for the LM1972

μPot is shown in Figure 16. This attenuation step

scheme, however, can be changed through programming techniques to fit different application requirements.

One such example would be a constant logarithmic attenuation scheme of 1dB steps for a panning function as

shown in Figure 17. The only restriction to the customization of attenuation schemes are the given attenuation

levels and their corresponding data bits shown in Table 1. The device will change attenuation levels only when a

channel address is recognized. When recognized, the attenuation level will be changed corresponding to the

data bits shown in Table 1. As shown in Figure 19, an LM1972 can be configured as a panning control which

separates the mono signal into left and right channels. This circuit may utilize the fundamental attenuation

scheme of the LM1972 or be programmed to provide a constant 1dB logarithmic attenuation scheme as shown in

Figure 17.

LM1972 Channel Attenuation

vs Digital Step Value

Figure 16. LM1972 Attenuation Step Scheme

LM1972 Channel Attenuation

vs Digital Step Value

(Programmed 1.0dB Steps)

Figure 17. LM1972 1.0dB

Attenuation Step Scheme

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