ADSP-2141L View Datasheet(PDF) - Analog Devices
Part Name
Description
MFG CO.
'ADSP-2141L' PDF : 39 Pages View PDF
ADSP-2141L
Table IV. Thermal Ratings: MQFP Package
Rating Description
Thermal Resistance (Case to Ambient)
Thermal Resistance (Junction to Ambient)
Thermal Resistance (Junction to Case)
Symbol
θCA
θJA
θJC
Value (MQFP Still Air)
30.7°C/W
35°C/W
4.3°C/W
Value (MQFP 9500 fpm)
16.7°C/W
21°C/W
4.3°C/W
ENVIRONMENTAL CONDITIONS
The following figures assume a four-layer JEDEC printed circuit
board:
TAMB = TCASE – (PD × θCA)
TCASE = Case Temperature in °C
OUTPUT DRIVE CURRENTS
Figures 28 and 29 show typical I-V characteristics for the
output drivers of the ADSP-2141L. The curves represent the
current drive capability of the output drivers as a function of
output voltage.
100
80
VDD = 3.3V @ +25؇C
60
VDD = 3.6V @ 0؇C
40
20
VDD = 3.0V @ +70؇C
0
VDD = 3.0V @ +70؇C
–20
VDD = 3.3V @ +25؇C
–40
VDD = 3.6V @ 0؇C
–60
–80
–100
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
SOURCE VOLTAGE – V
Figure 28. Typical Drive Currents (PCI Pins)
POWER DISSIPATION
Total power dissipation has two components: one due to inter-
nal circuitry and one due to the switching of external output
drivers. Internal power dissipation depends on the sequence in
which instructions execute and the data operands involved. See
IDDIN calculation in Electrical Characteristics section. Internal
power dissipation is calculated this way:
PINT = IDDIN × VDD
The external component of total power dissipation is caused by
the switching of output pins. Its magnitude depends on:
– the number of output pins that switch during each cycle (O)
– the maximum frequency at which the pins can switch (f)
– the load capacitance of the pins (C)
– the voltage swing of the pins (VDD).
The external component is calculated using:
PEXT = O × C × VDD2 × f
The load capacitance should include the processor’s package
capacitance (CIN). The frequency f includes driving the load
high and then back low.
80
VDD = 3.3V @ +25؇C
60
VOH
VDD = 3.6V @ 0؇C
40
20
VDD = 3.0V @ +70؇C
0
VDD = 3.0V @ +70؇C
–20
VOL VDD = 3.3V @ +25؇C
–40
–60
VDD = 3.6V @ 0؇C
–80
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
SOURCE VOLTAGE – V
Figure 29. Typical Drive Currents (Addr/Dbus/rd/wr Pins)
–34–
REV. 0
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