ADSP-2101BS-100 Datasheet, PDF (27/64 Pages) Analog Devices – TigerSHARC Embedded Processor

ADSP-21xx
SPECIFICATIONS (ADSP-2103/2162/2164)
POWER DISSIPATION EXAMPLE
To determine total power dissipation in a specific application,
the following equation should be applied for each output:
C × V_DD² × f
C = load capacitance, f = output switching frequency.
Example:
In an ADSP-2103 application where external data memory is
used and no other outputs are active, power dissipation is
calculated as follows:
Assumptions:
• External data memory is accessed every cycle with 50% of the
address pins switching.
• External data memory writes occur every other cycle with
50% of the data pins switching.
• Each address and data pin has a 10 pF total load at the pin.
• The application operates at V_DD = 3.3 V and t_CK = 100 ns.
Total Power Dissipation = P_INT + (C × V_DD2 × f )
P_INT = internal power dissipation (from Figure 23).
(C × V_DD2 × f ) is calculated for each output:
CAPACITIVE LOADING
Figures 24 and 25 show capacitive loading characteristics for the
ADSP-2103, ADSP-2162, and ADSP-2164.
30
25
V_DD = 3.0V
20
15
10
5
25 50 75 100 125 150
C_L – pF
Figure 24. Typical Output Rise Time vs. Load Capacitance, C_L
(at Maximum Ambient Operating Temperature)
Output
# of
Pins × C
× V_DD2 × f
Address, DMS 8
Data, WR 9
RD
1
CLKOUT 1
× 10 pF × 3.3² V × 10 MHz = 8.71 mW
× 10 pF × 3.3² V × 5 MHz = 4.90 mW
× 10 pF × 3.3² V × 5 MHz = 0.55 mW
× 10 pF × 3.3² V × 10 MHz = 1.09 mW
15.25 mW
Total power dissipation for this example = P_INT + 15.25 mW.
ENVIRONMENTAL CONDITIONS
Ambient Temperature Rating:
T_AMB = T_CASE – (PD × θ_CA)
T_CASE = Case Temperature in °C
PD = Power Dissipation in W
θ_CA = Thermal Resistance (Case-to-Ambient)
θ_JA = Thermal Resistance (Junction-to-Ambient)
θ_JC = Thermal Resistance (Junction-to-Case)
+8
+6
+4
+2
NOMINAL
–2
V_DD = 3.0V
25 50 75 100 125 150
C L – pF
Figure 25. Typical Output Valid Delay or Hold vs. Load
Capacitance, C_L (at Maximum Ambient Operating Temperature)
Package
PGA
PQFP
θ_JA
27°C/W
60°C/W
θ_JC
16°C/W
18°C/W
θ_CA
11°C/W
42°C/W
REV. B
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