5 thermal data (128-pin lqfp), 5 thermal data – Cirrus Logic CS4970x4 User Manual
Page 10
CS4970x4 Data Sheet
32-bit High Definition Audio Decoder DSP Family
DS752F1
10
5.5 Thermal Data (128-pin LQFP)
Notes:
1.
Two-layer board is specified as a 76 mm X 114 mm, 1.6 mm thick FR-4 material with 1-oz. copper covering 20% of the top and
bottom layers.
2.
Four-layer board is specified as a 76 mm X 114 mm, 1.6 mm thick FR-4 material with 1-oz. copper covering 20% of the top and
bottom layers and 0.5-oz. copper covering 90% of the internal power plane and ground plane layers.
3.
To calculate the die temperature for a given power dissipation
j
= Ambient Temperature + [ (Power Dissipation in Watts) *
ja
]
4.
To calculate the case temperature for a given power dissipation
c
=
j
- [ (Power Dissipation in Watts) *
jt
Parameter
Symbol
Min
Typ
Max
Unit
Thermal Resistance (Junction to Ambient)
Two-layer Board
ja
—
—
53
44
—
—
°C / Watt
Thermal Resistance (Junction to Top of Package)
Two-layer Board
jt
—
—
.45
.39
—
—
°C / Watt