tc9470fn TOSHIBA Semiconductor CORPORATION, tc9470fn Datasheet - Page 7

• Manufacturer Part Number: tc9470fn
• Description: Modulation Da Converter With Built-in 8-times Oversampling Digital Filter/dynamic Digital Bass Boost/analog Filter
• Manufacturer: TOSHIBA Semiconductor CORPORATION

5. Dynamic Digital Bass Boost Circuit
Table 4 Compressor Compression Characteristics (when in the parallel mode)
Figure 4 IIR Digital De-Emphasis Filter
condensers and analog switches. In addition to this, the coefficients are aligned to reduce error in the
de-emphasis filter characteristics.
pin (pin 20) and the DBB2 pin (pin 2).
microcontroller setting mode for further details on serial mode settings.)
The digitalization of the de-emphasis filter eliminates the need for such external components as resistors,
The filter structure and characteristics are shown below.
ON/OFF for the dynamic digital bass boost is controlled in the parallel mode (
This is set in the serial mode (
A block diagram for the dynamic bass boost circuit is shown in Figure 6.
The compressor’s compression ratio when in the control mode for the parallel mode is shown below.
The compressor’s compression characteristics are as follows:
Table 3 Compressor Compression Ratio (when in the parallel mode)
Input data
Transfer
function
Figure 6 Dynamic Digital Bass Boost Circuit Block
+
:
COMPRESSOR BLOCK
H
(Z)
a
INPUT
1
=
(b
Z
(1
L.P.F
0
í1
-
+
a
b
P/
1
1
Z
b
Z
S
-
1
-
1
1
b
)
)
= “L”) with a microcontroller or other equipment. (refer to 0.2
0
DBB max
DBB MID
DBB max
DBB MID
+
7
ATTENUATOR
SERIAL
í36dB
í24dB
18dB
12dB
+
Figure 5 Filter Characteristics
Coefficient length: 7 bits
|G (j
OUTPUT
&
)|
T
1
= 50 µs, T
1
/T
1
1
2
/T
P/
= 15 µs
2
S
= “H”) with the DBB
TC9470FN
2002-02-27