YDA131

7

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Mute function

When MUTE terminal is set at "H" level, all of the output buffer terminals, OUTPL, OUTML, OUTPR and OUTMR,

output "L" level, and this IC changes into mute state. When MUTE terminal is set at "L" level, all of the output buffer

terminals, OUTPL, OUTML, OUTPR and OUTMR, output digital pulse signal.

This IC includes a pop noise reduction function circuitry in both cases the mute control is enabled and disabled.

In the mute mode, the overcurrent detecting function is disabled. However, all the output buffers outputting "L" level, the

electric current is at a safe level even if the buffer terminals are short-circuited.

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Sleep function

When SLEEP terminal is set at "H" level, all of the internal circuitries are placed in the shut-off state, output is placed in the

mute state, and this IC is placed in the sleep state. In this state, the power consumption is minimized, overcurrent detection

function and high temperature detection function are disabled, and warning signal (PROT terminal output) is set at "L"

level.

When SLEEP terminal is set at "L" level, this IC goes into normal operation state after sufficient time (starting time) to

make each reference voltage reaches an established potential.

This IC includes a pop noise reduction function in both cases the sleep control is enabled and disabled.

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Overcurrent detection function and high temperature detection function

This IC includes the output buffer overcurrent detection function and high temperature detection function. When either

detection circuit detects an abnormality, warning signal (PROT terminal ) output is set at "H" level.

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Overcurrent detection function

When either of four speakers terminal end (between LC filter and speaker) short-circuits with VSS terminal or reverse

polarity speaker terminal end, this IC determines that the overcurrent state has occurred and outputs warning signal

(PROT terminal ="H" level).

When a warning is signaled, MUTE terminal or SLEEP terminal should be controlled externally to place this IC in the

muted state or sleep state immediately to protect this IC.

And it does not cope with over current protection that short-circuiting of output terminals (OUTPL, OUTML, OUTPR,

OUTMR) and VSS terminal, and short-circuiting between each output terminal.

When the warning signal (PROT terminal ="H" level) is outputted due to overcurrent detection, this IC keeps the

warning signal output after the current return to normal state.

The warning signal is cancelled by changing the state of SLEEP terminal as "L" level, "H" level and "L" level in this

order or by turning on the power supply again.