tb2923ahq TOSHIBA Semiconductor CORPORATION, tb2923ahq Datasheet - Page 7

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

5. Pop Noise Suppression
6. External Component Constants
Component
C1
C2
C3
C4
C5
C6
Since the TB2923AHQ uses the AC-GND pin (pin 16) as the common input reference voltage pin for all
amplifiers, the ratio of the input capacitance (C1) to the AC-to-GND capacitance (C6) should be 1:4.
Also, if power is removed before C1 and C6 are completely charged, pop noise will be generated because of
unbalanced DC currents.
To avoid this problem, it is recommended to use a larger capacitor as C2 to increase the charging times of C1
and C6. Note, however, that C2 also affects the time required from power-on to audio output.
The pop noise generated by the muting and unmuting of the audio output varies with the time constant of
C4. A larger capacitance reduces the pop noise, but increases the time from when the mute control signal is
applied to C4 to when the mute function is enabled.
Recommended
3900 μF
0.22 μF
0.1 μF
Value
10 μF
1 μF
1 μF
To eliminate DC
To reduce ripple
To provide
sufficient
oscillation margin
To reduce pop
noise
Ripple filter
Common
reference voltage
for all input
Purpose
Cut-off frequency is
increased.
Powering on/off is faster.
Reduces noise and provides sufficient oscillation margin
High pop noise. Duration until
mute function is turned on/off
is short.
Power supply humming and ripple filtering.
Pop noise is suppressed when C1: C6 = 1:4.
recommended value
When lower than
7
Effects
Cut-off frequency is reduced.
Powering on/off is slower.
Low pop noise. Duration until
mute function is turned on/off
is long.
recommended value
When higher than
TB2923AHQ
Pop noise is
generated
when V
turned on.
Pop noise is
generated
when V
turned on.
2009-01-29
Notes
CC
CC
is
is