TFA9842J/N1.112 NXP Semiconductors, TFA9842J/N1.112 Datasheet - Page 5

• Manufacturer Part Number: TFA9842J/N1.112
• Manufacturer: NXP Semiconductors

Specifications of TFA9842J/N1.112

• Operational Class: Class-AB
• Output Power (typ): 15x1@8Ohm/7.5x2@4OhmW
• Audio Amplifier Function: Speaker
• Total Harmonic Distortion: 0.05@8Ohm@1W%
• Single Supply Voltage (typ): 17V
• Dual Supply Voltage (typ): Not RequiredV
• Power Supply Requirement: Single
• Power Dissipation: 35W
• Rail/rail I/o Type: No
• Single Supply Voltage (min): 9V
• Single Supply Voltage (max): 26V
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Through Hole
• Pin Count: 9
• Lead Free Status / RoHS Status: Compliant

Philips Semiconductors
9397 750 12013
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
The maximum output power is limited by the supply voltage of 26 V and the maximum
available output current is 3 A (repetitive peak current). A minimum load for SE of 4
and for BTL of 16
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
0 dB and 12 dB, respectively (see
Table 4:
For the average listening level a power dissipation of 4.2 W can be used for a
heatsink calculation.
The TFA9842J 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
Ripple frequency on the supply voltage is twice the signal frequency
No expensive DC-blocking capacitor
Good low frequency performance.
= 8 ) at THD = 0.2 % (see
2.0 V) to V
CC
Power rating as function of headroom
Mode selection
=
=
5 10
---------------
15.85
3.5 V)
CC
10 10
------------------
15.85
CC
= 18 V and P
Power output
SE
P
P
Rev. 01 — 26 April 2004
3
o
o(ALL)
is required for V
Figure
= 5 W
=
3
=
315 mW
= 315 mW
630 mW
6.
o
Figure
= 5 W (SE with R
Table
CC
BTL
P
P
2-channel audio amplifier (2 x SE or 1 x BTL)
Table 5
o
o(ALL)
7), the Average Listening Level (ALL) music
= 10 W
> 22 V; see
4).
= 630 mW
Amplifiers 1 and 2
standby
mute
on
Figure 9
and
Figure
L
Figure
= 4 ) or P
(SE and BTL) for a headroom of
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Power dissipation
(both channels driven)
P
P
D
D
3).
= 8.4 W
= 4.2 W
5.
o
TFA9842J
= 10 W (BTL with
5 of 21
(4)
(5)