NXP Semiconductors TDA8948J, Product Data Sheet

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TDA8948J_1 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 01 — 27 February 2008 7 of 26
NXP Semiconductors
TDA8948J
4-channel audio amplifier
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 ).
8.4 Supply voltage ripple rejection
The Supply Voltage Ripple Rejection (SVRR) is measured with an electrolytic capacitor of
150
µ
F on pin SVR using a bandwidth of 20 Hz to 22 kHz. Figure 10 illustrates the SVRR
as function of the frequency. A larger capacitor value on pin SVR improves the ripple
rejection behavior at the lower frequencies.
Table 5. Mode selection
Voltage on pin Channel 1 and 2 Channel 3 and 4
(sub woofer)
MODE1 MODE2
0 V to 0.8 V 0 V to V
CC
Standby mode Standby mode
4.5 V to (V
CC
−
3.5 V) 0 V to V
CC
Mute mode Mute mode
(V
CC
−
2.0 V) to V
CC
0 V to (V
CC
−
3.5 V) On mode Mute mode
(V
CC
−
2 V) to V
CC
On mode On mode
Fig 3. Mode selection
mdb016
channels 3
+
4: mute
channels 1
+
2: on
channels 3
+
4: on or mute
channels 3
+
4: on
V
CC
−
3.5 V
CC
V
MODE2
V
CC
−
2.0
all standby all mute
0.8 4.5 V
CC
−
3.5
V
CC
V
MODE1
V
CC
−
2.0