TC9470FN Datasheet, PDF (11/19 Pages) Toshiba Semiconductor – Modulation DA Converter with Built-in 8-Times Oversampling Digital Filter/Dynamic Digital Bass Boost/Analog Filter

TC9470FN
8. Soft Mute Circuit
The IC is equipped with a soft mute function, and this enables a soft mute to be set for the DA converter
output by switching the SM pin (pin 18) from the “L” level to the “H” level when in the parallel mode
( P/S = “H”). The soft mute’s ON/OFF function and the DA converter output are shown in Figure 12.
The Soft mute ON/OFF control function is disabled during level transition.
SM Pin Input
Off
On
Off
DA Converter
Output Level
1
1
64
64
Approximately 23 ms
Approximately 23 ms
Figure 12 Changes in the Soft Mute DA Converter Output Level
9. Common Left Channel/Right Channel Digital Zero Data Detection Output Circuit
The IC is equipped with a common left channel/right channel digital zero data detection output circuit,
and the ZD pin (pin 11) is switched from “L” to “H” when data for both the left channel and the right
channel becomes zero data for approximately 350 ms or longer.
This is fixed at “L” when the data for the left channel and right channel is not zero data.
10. Description of Internal Control Signals
The P/S pin can be used to switch between the parallel mode ( P/S pin = “H” in DC setting mode) and
the serial mode ( P/S pin = “L” with the microcontroller interface function).
10.1
Parallel Mode ( _P/S = “H”: DC setting mode)
Pins 18, 19, 20 and 21 are used as the mode setting pins shown in the table below when in the
parallel mode.
Table 6 Pin Names at the Parallel Mode
Pin No.
18
19
20
21
Pin Name
Pin Description
SM
EMP
DBB1
DBB2
Soft mute control pin
De-emphasis control pin
Digital bass boost mode control pin 1
Digital bass boost mode control pin 2
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2002-02-27