ADSP-BF542 AD [Analog Devices], ADSP-BF542 Datasheet - Page 65

• Manufacturer Part Number: ADSP-BF542
• Description: Embedded Processor
• Manufacturer: AD [Analog Devices]

Preliminary Technical Data
Example System Hold Time Calculation
To determine the data output hold time in a particular system,
first calculate t
to be the difference between the ADSP-BF542/4/7/8/9 proces-
sor’s output voltage and the input threshold for the device
requiring the hold time. A typical ΔV will be 0.4 V. C
bus capacitance (per data line), and I
three-state current (per data line). The hold time will be t
plus the minimum disable time (for example, t
chronous memory write cycle).
(MEASURED)
(MEASURED)
OUTPUT
OUTPUT
Figure 36. Voltage Reference Levels for AC
Measurements (Except Output Enable/Disable)
INPUT
Figure 35. Equivalent Device Loading for AC Measurements
(Includes All Fixtures)
t
PIN
TO
DIS
OR
V
V
OH
OL
OUTPUT STOPS DRIVING
1.5V
DECAY
Figure 34. Output Enable/Disable
using the equation given above. Choose ΔV
REFERENCE
t
V
V
DIS_MEASURED
OH
OL
SIGNAL
t
(MEASURED)
(MEASURED) +
DECAY
VOLTAGE TO BE APPROXIMATELY 1.5V.
30pF
TEST CONDITIONS CAUSE THIS
HIGH IMPEDANCE STATE.
t
50
ENA
L
is the total leakage or
V
V
OUTPUT STARTS DRIVING
DDAT
t
2.0V
1.0V
Rev. PrG | Page 65 of 82 | December 2007
1.5V
ENA-MEASURED
1.5V
t
for an asyn-
TRIP
L
(MEASURED)
(MEASURED)
is the total
V
V
OH
OL
DECAY
ENVIRONMENTAL CONDITIONS
To determine the junction temperature on the application
printed circuit board use:
where:
T
T
center of package.
Ψ
P
the method to calculate P
Values of θ
circuit board design considerations. θ
order approximation of T
where:
T
Values of θ
circuit board design considerations when an external heatsink is
required.
Values of θ
circuit board design considerations.
In
dards JESD51-2 and JESD51-6, and the junction-to-board
measurement complies with JESD51-8. The junction-to-case
measurement complies with MIL-STD-883 (Method 1012.1).
All measurements use a 2S2P JEDEC test board.
Table 53. Thermal Characteristics, 400-Ball CSP_BGA
Parameter
θ
θ
θ
Ψ
D
J
CASE
A
JT
JA
JB
JC
= Junction temperature ( C)
Table
JT
= Power dissipation (see
= Ambient temperature ( C)
= From
= Case temperature ( C) measured by customer at top
53, airflow measurements comply with JEDEC stan-
JA
JC
JB
Table 53
are provided for package comparison and printed
are provided for package comparison and printed
are provided for package comparison and printed
Condition
0 linear m/s air flow
1 linear m/s air flow
2 linear m/s air flow
0 linear m/s air flow
1 linear m/s air flow
2 linear m/s air flow
T J
T J
=
T CASE
=
D
J
T A
)
by the equation:
Power Dissipation on Page 64
ADSP-BF542/4/7/8/9
+
+
(
θ JA
(
Ψ JT P D
×
JA
P D
×
can be used for a first
)
)
Typical
18.4
15.8
15.0
9.75
6.37
0.27
0.60
0.66
Unit
C/W
C/W
C/W
C/W
C/W
C/W
C/W
C/W
for