tfa9843j-02 NXP Semiconductors, tfa9843j-02 Datasheet - Page 5

• Manufacturer Part Number: tfa9843j-02
• Description: Tfa9843j 2-channel Audio Amplifier Se 1 W To 20 W Or Btl 4 W To 40 W
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 12587
Preliminary data
8.2.1 Output power measurement
8.2.2 Headroom
8.3 Mode selection
The output power as a function of the supply voltage is measured on the output pins
at THD = 10 %; see
voltage of 26 V and the maximum available output current is 4 A repetitive peak
current. A minimum load (SE) of 3
Figure
Figure
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
R
power without any distortion yields:
The power dissipation can be derived from
respectively 12 dB headroom (see
Table 4:
For the average listening level a power dissipation of 4.2 W can be used for a
heatsink calculation.
The TFA9843J has three functional modes, which can be selected by applying the
proper DC voltage to pin MODE (see
Table 5:
P
P
Headroom
0 dB
12 dB
V
0 to 0.8 V
4.5 V to (V
(V
•
•
L
o ALL SE
o ALL BTL
MODE
CC
No expensive DC-blocking capacitor
Good low frequency performance.
= 8 ) at THD = 0.2 % (see
2.0 V) to V
5. A minimum load (BTL) of 6
6.
CC
Power rating as function of headroom
Mode selection
=
=
5 10
---------------- -
3.5 V)
15.85
CC
10 10
------------------- -
15.85
CC
Rev. 02 — 19 January 2004
= 18 V and P
Power output (THD = 0.2 %)
SE
P
P
o
o(ALL)
3
Figure
= 5 W
=
3
=
315 mW
= 315 mW
630 mW
11. The maximum output power is limited by the supply
o
Figure
= 5 W (SE with R
Table
BTL
P
P
2-channel audio amplifier (2 x SE or 1 x BTL)
is required for supply voltages > 22 V; see
Table 5
o
o(ALL)
7), the Average Listening Level (ALL) music
= 10 W
is required for supply voltages > 22 V; see
4).
Figure 13
= 630 mW
Amplifiers 1 and 2
standby
mute
on
and
Figure
L
= 4 ) or P
(SE) or
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Power dissipation (P
both channels driven
8.4 W
4.2 W
3).
Figure 14
o
TFA9843J
= 10 W (BTL with
(BTL) for 0 dB
D
);
5 of 21
(4)
(5)