TB2903HQ Toshiba, TB2903HQ Datasheet - Page 4

• Manufacturer Part Number: TB2903HQ
• Manufacturer: Toshiba

Specifications of TB2903HQ

• No. Of Channels: 4
• Package: HZIP 25-P-1.00F
• Recommended Vcc (v): 13.2
• Rl=2 Ohm: Not Supported
• Rl=4 Ohm: 50W x 4
• Rl=8 Ohm: -
• Features/built-in Functions: 4 BTL channels, standby switch, mute, BiCD process, offset detection
• Operating Voltage (v): 9 to 18

3. Muting Function
Figure 4 Muting Function
Audio muting function is enabled when pin 22 is Low. When the time constant of the muting function is
determined by R
the power or muting function is turned ON/OFF will vary according to the time constant. (Refer to Figure 4
and Figure 5.)
The pin 22 is designed to operate off 5 V.
Moreover, this terminal (pin 22) serves as the source switch of current of an internal mute circuit. And it is
designed so that the discharge current of this terminal (pin 22) may serve as 200 µA. The outside pull-up
resistor R
ex) When control voltage is changed in to 6 V from 5 V.
To obtain enough mute attenuation, a series resistor, R
5 V
R
1
6 V/5 V × 47 k = 56 k
C
1
4
is determind on the basic of this value.
22
1
and C
1 kΩ
Stand-By
(pin 22)
V
4,
CC
it should take into account the pop noise. The pop noise which is generated when
Small current capacity switch
Large current capacity switch
Mute ON/OFF
control
V
CC
Battery
– Standby Switch Method –
Battery
– Conventional Method –
Figure 3
4
Figure 5 Mute Attenuation − V
1
−100
−120
From microcomputer
at pin 22 should be 47 kΩ or more.
−20
−40
−60
−80
20
0
0
V
f = 1kHz
R
V
V
CC
L
OUT
Stand-By
CC
= 4 Ω
= 13.2 V
= 20dBm
0.5
Pin 22 control voltage: V MUTE (V)
V
1
Relay
CC
ATT – V
1.5
MUTE
From
microcomputer
Battery
Battery
2
2.5
TB2903HQ
2004-07-25
MUTE
3
(V)