tb2921ahq TOSHIBA Semiconductor CORPORATION, tb2921ahq Datasheet - Page 4

• Manufacturer Part Number: tb2921ahq
• Description: 51 W ? 4-ch Btl Audio Power Ic
• Manufacturer: TOSHIBA Semiconductor CORPORATION

2. Mute Function
3. High-Side Switch
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.
Pin 25 of this device is used as a high-side switch to a V
pin. Thus, the power amplifier IC and the connected external unit (such as the hideaway unit) can be
simultaneously turned on or off by using the standby switch.
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
CC
Figure 4 Mute Attenuation − V
power supply, which is interlocked with a standby
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
TB2921AHQ
MUTE
2
MUTE
2009-02-03
(V)
2.5
(V)
3