ADSP-BF606 AD [Analog Devices], ADSP-BF606 Datasheet - Page 35

• Manufacturer Part Number: ADSP-BF606
• Description: Blackfin Dual Core
• Manufacturer: AD [Analog Devices]

Preliminary Technical Data
ENVIRONMENTAL CONDITIONS
To determine the junction temperature on the application
printed circuit board use:
where:
T
T
center of package.
Ψ
P
for the method to calculate P
Table 13. Thermal Characteristics
Values of θ
circuit board design considerations. θ
order approximation of T
where:
T
Table 14. Thermal Diode Parameters – Transistor Model
1
2
3
4
Parameter
θ
θ
θ
θ
Ψ
Ψ
Ψ
Symbol
I
I
n
R
Analog Devices does not recommend operation of the thermal diode under reverse bias.
Not 100% tested. Specified by design characterization.
The ideality factor, nQ, represents the deviation from ideal diode behavior as exemplified by the diode equation: I
The series resistance (R
FW
E
J
CASE
D
A
q = electronic charge, V
JT
JA
JMA
JMA
JC
Q
T
= Junction temperature (°C)
JT
JT
JT
3, 4
= Power dissipation (see
= Ambient temperature (°C)
2, 3
1
= From
= Case temperature (°C) measured by customer at top
JA
Table 13
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
T
J
) can be used for more accurate readings as needed.
T
BE
=
J
Parameter
Forward Bias Current
Emitter Current
Transistor Ideality
Series Resistance
= voltage across the diode, k = Boltzmann Constant, and T = absolute temperature (Kelvin).
=
T
J
CASE
T
by the equation:
Total Power Dissipation on Page 34
A
D
)
+
+
(
θ
(
JA
Ψ
JT
×
JA
P
×
can be used for a first
D
P
)
D
)
Typical
16.7
14.6
13.9
4.41
0.11
0.24
0.25
ADSP-BF606/ADSP-BF607/ADSP-BF608/ADSP-BF609
Rev. PrD | Page 35 of 44 | March 2012
Unit
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
Min
TBD
TBD
TBD
TBD
Values of θ
circuit board design considerations when an external heat sink
is required.
In
dards JESD51-2 and JESD51-6. The junction-to-case
measurement complies with MIL-STD-883 (Method 1012.1).
All measurements use a 2S2P JEDEC test board.
Thermal Diode
The processor incorporates thermal diode/s to monitor the die
temperature. The thermal diode is a grounded collector, PNP
Bipolar Junction Transistor (BJT). The SYS_TDA pin is con-
nected to the emitter and the SYS_TDK pin is connected to the
base of the transistor. These pins can be used by an external
temperature sensor (such as ADM 1021A or LM86 or others) to
read the die temperature of the chip.
The technique used by the external temperature sensor is to
measure the change in V
at two different currents. This is shown in the following
equation:
where:
n = multiplication factor close to 1, depending on process
variations
k = Boltzmann’s constant
T = temperature (°C)
q = charge of the electron
N = ratio of the two currents
The two currents are usually in the range of 10 micro Amperes
to 300 micro Amperes for the common temperature sensor
chips available.
Table 14
transistor model. Note that Measured Ideality Factor already
takes into effect variations in beta (Β).
Table
13, airflow measurements comply with JEDEC stan-
Typ
TBD
TBD
contains the thermal diode specifications using the
JC
ΔV
are provided for package comparison and printed
BE
=
C
= I
n
S
×
× (e
kT
----- -
q
BE
qVBE/nqkT
×
when the thermal diode is operated
In(N)
Max
TBD
TBD
TBD
TBD
–1), where I
S
= saturation current,
Unit
μA
μA
Ω