tfa9842j-n1 NXP Semiconductors, tfa9842j-n1 Datasheet - Page 15

• Manufacturer Part Number: tfa9842j-n1
• Description: 2-channel Audio Amplifier; Se 1 W To 7.5 W; Btl 2 W To 15 W
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 12013
Preliminary data
13.1.2 Power supply decoupling
13.2 Thermal behavior and heatsink calculation
Proper supply bypassing is critical for low-noise performance and high supply voltage
ripple rejection. The respective capacitor location should be as close as possible to
the device and grounded to the power ground. Proper power supply decoupling also
prevents oscillations.
For suppressing higher frequency transients (spikes) on the supply line a capacitor
with low ESR, typical 100 nF, has to be placed as close as possible to the device. For
suppressing lower frequency noise and ripple signals, a large electrolytic capacitor,
e.g. 1000 F or greater, must be placed close to the device.
The bypass capacitor on pin SVR reduces the noise and ripple on the mid rail
voltage. For good THD and noise performance a low ESR capacitor is recommended.
The measured maximum thermal resistance of the IC package, R
A calculation for the heatsink can be made, with the following parameters:
R
the heatsink. This can be calculated using the maximum temperature increase
divided by the power dissipation:
Fig 14. Printed-circuit board layout (single-sided); components view.
th(tot)
T
V
T
R
amb(max)
j(max)
CC
th(tot)
= 18 V and R
is the total thermal resistance between the junction and the ambient including
= 150 C (specification)
= (T
= 60 C (example)
j(max)
CIV
Rev. 01 — 26 April 2004
22
L
T
F
CIV
amb(max)
= 4
SGND
220
(SE)
nF
AUDIO POWER CS NIJMEGEN
)/P
D
IN2
P
F
2-channel audio amplifier (2 x SE or 1 x BTL)
TFA9843J
/
3
220
nF
0
TVA
0
IN1
2
100 nF
n .
J a
7
2
1000 F
+V P
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
k
10
150 F
MUTE
SB ON
10 k
MODE
TFA9842J
th(j-mb)
MCE506
, is 2.0 K/W.
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