Owner's manual

DS868PP2 Copyright 2008 Cirrus Logic, Inc. 11
CS49DV8C Data Sheet
32-bit Audio DSP Family
5.4 Power Supply Characteristics
(Measurements performed under operating conditions.)
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
Τ
j
= Ambient Temperature + [ (Power Dissipation in Watts) * θ
ja
]
4.To calculate the case temperature for a given power dissipation
Τ
c
= Τ
j
- [ (Power Dissipation in Watts) * ψ
jt
]
Input leakage current (all digital pins with internal
pull-up resistors enabled, and XTI)
I
IN-PU
--50μA
Parameter Min Typ Max Unit
Power supply current:
Core and I/O operating: VDD
1
PLL operating: VDDA
With external memory and most ports operating: VDDIO
1.Dependent on application firmware and DSP clock speed.
-
-
-
500
3.5
120
-
-
-
mA
mA
mA
Parameter Symbol Min Typ Max Unit
Thermal Resistance (Junction to Ambient)
Two-layer Board
1
Four-layer Board
2
θ
ja
-
-
48
40
-
-
°C / Watt
Thermal Resistance (Junction to Top of Package)
Two-layer Board
1
Four-layer Board
2
ψ
jt
-
-
.39
.33
-
-
°C / Watt
Parameter Symbol Min Typ Max Unit