tb2923ahq TOSHIBA Semiconductor CORPORATION, tb2923ahq Datasheet - Page 4

• Manufacturer Part Number: tb2923ahq
• Description: 51 W ? 4-ch Btl Audio Power Ic
• Manufacturer: TOSHIBA Semiconductor CORPORATION

2. Mute Function
The audio mute function is enabled by setting pin 22 Low. R
mute function. The time constant affects pop noise generated when power or the mute function is turned on
or off; thus, it must be determined on a per-application basis. (Refer to Figures 3 and 4.)
The value of the external pull-up resistor is determined, based on pop noise value.
For example, when the control voltage is changed from 5 V to 3.3 V, the pull-up resistor should be:
5 V
R
1
3.3 V / 5 V × 47 kΩ = 31 kΩ
Figure 3 Mute Function
C
4
(pin 22)
22
1 kΩ
Mute On/Off
control
4
Figure 4 Mute Attenuation − V
1
−100
−120
−20
−40
−60
−80
and C
20
0
0
V CC = 13.2 V
f = 1 kHz
R L = 4 Ω
V O = 20dBm
BW = 400 Hz to 30 kHz
4
determine the time constant of the
0.5
Pin 22 control voltage: V
1
ATT – V
1.5
MUTE
TB2923AHQ
MUTE
2
MUTE
2009-01-29
(V)
2.5
(V)
3