TFA9879 NXP Semiconductors, TFA9879 Datasheet - Page 46

• Manufacturer Part Number: TFA9879
• Description: The TFA9879 contains a processor that supports a range of sound processing featuresincluding a 5-band parametric equalizer, separate bass and treble control, a dynamicrange compressor, soft clip control and volume control
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TFA9879
Product data sheet
15.4.1 EMC considerations
15.4.2 Thermal considerations
15.4 PCB layout considerations
Great care should be taken when designing the PCB layout for a Class-D amplifier circuit
as the layout can affect the audio performance, the EMC performance and/or the thermal
performance, and can even affect the functionality of the TFA9879.
The decoupling capacitors on pins V
TFA9879, referenced to a solid ground plane. The exposed DAP should also be
connected to this ground plane.
The TFA9879 is available in a thermally enhanced HVQFN24 (SOT616-3) package for
reflow soldering. The HVQFN24 has an exposed DAP that significantly reduces the
thermal resistance, R
DAP should be soldered to a thermal copper plane. Increasing the area of the thermal
plane, the number of planes or the copper thickness can further reduce the thermal
resistance. The typical thermal resistance (free air and natural convection) of a practical
PCB implementation is:
Equation 15
(P) and the thermal resistance from junction to ambient.
where:
OTP will limit the maximum junction temperature to 130 °C to avoid thermal damage.
R
th j-a
R
base material).
R
T
T
P = power dissipated in the TFA9879
(
j(max)
amb
th(j-a)
th(j-a)
)
= ambient temperature
=
= 67 K/W for a two-layer application board (18 mm × 22 mm, 35 μm copper, FR4
= thermal resistance from junction to ambient
= maximum junction temperature (125 °C)
T
---------------------------------- -
j max
(
describes the relationship between the maximum allowable power dissipation
All information provided in this document is subject to legal disclaimers.
)
P
–
T
amb
th(j-a)
Rev. 02 — 15 October 2010
. To achieve a lower overall thermal resistance, the exposed
Mono BTL class-D audio amplifier with digital input
DDD
, V
DDP
and STABA should be placed close to the
TFA9879
© NXP B.V. 2010. All rights reserved.
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