Try to imagine the possibilities to integrate full audio tone, balance, and volume control into your multimedia computer product, and you integrate it without having to resort to any manual knobs. Naturally we could integrate it with a bunch of DACs all running under microprocessor control, but what happens if the processor has had a chance to reload the preset values into the DACs before the audio amplifiers and sound generators come alive. Before the initialization sequence is complete, you could get blasted.

Digital Control for Tone Volume and Balance2 circuit schematic

Fortunately, this problem has been solved by Intersil with the X9241 XDCPs. We can store the last position set by control and automatically reload these values into the pot tap registers upon power-up using this device. The figure below shows the Intersil X9241U quad 50KW XDCP used to control the treble, bass, balance, and volume parameters of the LM1035 stereo audio processor. The Intersil is different with conventional DAC, Intersil can reload the last value, or a preset value, into the tone/balance and volume register upon power-up. It will make us get predictable sound level conditions without any danger of over-driving the power amplifier. [Source: Intersil Application Note]