tfa9843aj NXP Semiconductors, tfa9843aj Datasheet - Page 5

• Manufacturer Part Number: tfa9843aj
• Description: Tfa9843aj 20 W Stereo Power Amplifier With Volume Control
• Manufacturer: NXP Semiconductors

Philips Semiconductors
TFA9843AJ_1
Preliminary data sheet
8.2.2 Headroom
8.3 Mode selection
8.4 Supply voltage ripple rejection
Typical CD music requires at least 12 dB (factor 15.85) dynamic headroom, compared to
the average power output, for transferring the loudest parts without distortion. At
V
Average Listening Level (ALL) music power without any distortion yields:
The power dissipation can be derived from
headroom; see
For the average listening level a power dissipation of 4.2 W can be used for a heatsink
calculation.
Table 4.
The TFA9843AJ has four functional modes, which can be selected by applying the proper
DC voltage to pin VC; see
Table 5.
The supply voltage ripple rejection (SVRR) is measured with an electrolytic capacitor of
150 F connected to pin SVR with a bandwidth of 20 Hz to 22 kHz. The SVRR as a
function of the frequency is illustrated in
improves the ripple rejection behavior at the lower frequencies.
P
Headroom
0 dB
12 dB
V
0 V to 0.8 V
1.2 V to 1.5 V
1.5 V to 5.0 V
5.0 V to V
CC
o ALL SE
I(VC)
= 18 V and P
CC
=
Power rating as function of headroom
Mode selection
------------ -
15.85
6.5
Table
Status
Standby
Mute
Volume control
On (maximum gain)
o
=
= 6.5 W (SE with R
410 mW
4.
Rev. 01 — 28 April 2006
Table
Power output (THD < 0.5 %)
(SE)
P
P
o
o(ALL)
5.
= 6.5 W
Definition
in this mode the current consumption is very low
and the outputs are floating; the device is in
Standby mode when V
in this mode the amplifier is DC-biased but not
operational (no audio output); this allows the input
coupling capacitors to be charged to avoid plop
noise; the device is in Mute mode when
1.2 V < V
in this mode the volume of the amplifier can be
controlled; the gain can be adjusted between the
range of 1.5 V < V
in this mode the amplifier has its maximum gain; the
Operating mode is activated at V
= 410 mW
20 W stereo power amplifier with volume control
L
= 4 ) at THD < 0.5 % (see
Figure
Figure 8
I(VC)
10. A larger capacitor value on pin SVR
< 1.5 V
(SE) for 0 dB respectively 12 dB
I(VC)
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
< 5.0 V
I(VC)
Power dissipation (P);
both channels driven
8.2 W
4.2 W
< 0.8 V
TFA9843AJ
Figure
I(VC)
> 5.0 V
5), the
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