CS4953xx Data Sheet

32-bit Audio Decoder DSP Family

DS705F2

11

5.5 Thermal Data (144-pin LQFP)

5.6 Thermal Data (128-pin LQFP)

of the top & bottom layers.

2.

Four-layer board is specified as a 76 mm X 114 mm, 1.6 mm thick FR-4 material with 1-ounce copper covering

20 % of the top & bottom layers and 0.5-ounce copper covering 90 % of the internal power plane and ground plane

layers.

3.

To calculate the die temperature for a given power dissipation

Τ

θ

4.

To calculate the case temperature for a given power dissipation

Τ

Τ

Parameter

Symbol

Min

Typ

Max

Unit

Thermal Resistance (Junction to Ambient)

Two-layer Board1

Four-layer Board2

θ

ja

—

—

48

40

—

—

°C / Watt

Thermal Resistance (Junction to Top of Package)

Two-layer Board1

Four-layer Board2

ψ

jt

—

—

.39

.33

—

—

°C / Watt

Parameter

Symbol

Min

Typ

Max

Unit

Thermal Resistance (Junction to Ambient)

Two-layer Board1

Four-layer Board2

θ

ja

—

—

53

44

—

—

°C / Watt

Thermal Resistance (Junction to Top of Package)

Two-layer Board1

Four-layer Board2

ψ

jt

—

—

.45

.39

—

—

°C / Watt