TDA8947J Datasheet, PDF (7/24 Pages) NXP Semiconductors – 4-channel audio amplifier (SE: 1 W to 25 W; BTL: 4 W to 50 W)

Philips Semiconductors
TDA8947J
4-channel audio amplifier
Mute — The amplifier is DC-biased, but not operational (no audio output). This allows
the input coupling capacitors to be charged to avoid pop-noise. The device is in the
mute mode when 4.5 V < V_MODE1 < (V_CC − 3.5 V).
On — The amplifier is operating normally. The on mode is activated at
V_MODE1 > (V_CC − 2.0 V). The output of channels 3 and 4 can be set to mute or on
mode.
The output channels 3 and 4 can be switched on/off by applying a proper DC voltage
to pin MODE2, under the condition that the output channels 1 and 2 are in the on
mode (see Figure 3).
Table 5: Mode selection
Voltage on pin
MODE1
MODE2
0 to 0.8 V
4.5 to (V_CC − 3.5 V)
(V_CC − 2.0 V) to V_CC
0 to V_CC
0 to V_CC
0 to (V_CC − 3.5 V)
(V_CC − 2 V) to V_CC
Channel 1 and 2
standby
mute
on
on
Channel 3 and 4
(sub woofer)
standby
mute
mute
on
all standby
all mute
channels 1+2: on
channels 3+4: on or mute
0.8
4.5
VCC−3.5 VCC−2.0 VCC
VMODE1
channels 3+4: mute
channels 3+4: on
MDB016
Fig 3. Mode selection.
VCC−3.5 VCC−2.0 VCC
VMODE2
8.4 Supply voltage ripple rejection
The Supply Voltage Ripple Rejection (SVRR) is measured with an electrolytic
capacitor of 150 µF on pin SVR using a bandwidth of 20 Hz to 22 kHz. Figure 11
illustrates the SVRR as function of the frequency. A larger capacitor value on pin SVR
improves the ripple rejection behavior at the lower frequencies.
9397 750 10779
Preliminary data
Rev. 01 — 06 February 2004
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
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