adsp-2165ks-80 Analog Devices, Inc., adsp-2165ks-80 Datasheet - Page 15

• Manufacturer Part Number: adsp-2165ks-80
• Description: Dsp Microcomputers With Rom
• Manufacturer: Analog Devices, Inc.

ADSP-2161/ADSP-2163/ADSP-2165
POWER DISSIPATION EXAMPLE
To determine total power dissipation in a specific application,
the following equation should be applied for each output:
C = load capacitance, f = output switching frequency.
Example:
In an ADSP-2161 application where external data memory is
used and no other outputs are active, power dissipation is calcu-
lated as follows:
Assumptions:
• External data memory is accessed every cycle with 50% of
• External data memory writes occur every other cycle with
• Each address and data pin has a 10 pF total load at the pin.
• The application operates at V
P
(C
Output
Address, DMS 8
Data, WR
RD
CLKOUT
Total power dissipation for this example = P
ENVIRONMENTAL CONDITIONS
Ambient Temperature Rating:
Package
PLCC
MQFP
REV. 0
T
T
PD = Power Dissipation in W
INT
CA
JA
JC
the address pins switching.
50% of the data pins switching.
AMB
CASE
= internal power dissipation (from Figure 9).
= Thermal Resistance (Junction-to-Ambient)
= Thermal Resistance (Junction-to-Case)
V
= Thermal Resistance (Case-to-Ambient)
DD
= T
= Case Temperature in C
Total Power Dissipation = P
2
CASE
f ) is calculated for each output:
– (PD
# of
Pins
9
1
1
27 C/W
60 C/W
JA
10 pF
10 pF
10 pF
10 pF
C
CA
C
)
V
DD
DD
2
5
5
5
5
INT
V
= 5.0 V and t
2
2
2
2
DD
V
V
V
V
f
+ (C
16 C/W
18 C/W
2
JC
20 MHz = 40.0 mW
10 MHz = 22.5 mW
10 MHz = 2.5 mW
20 MHz = 5.0 mW
INT
f
V
+ 70.0 mW.
DD
CK
2
= 50 ns.
f )
70.0 mW
11 C/W
42 C/W
CA
–15–
CAPACITIVE LOADING
Figures 10 and 11 show capacitive loading characteristics for the
ADSP-2161/ADSP-2163/ADSP-2165.
Figure 10. Typical Output Rise Time vs. Load Capacitance, C
(at Maximum Ambient Operating Temperature)
Figure 11. Typical Output Valid Delay or Hold vs. Load
Capacitance, C
Temperature)
–1
–2
–3
8
7
6
5
4
3
2
1
0
5
4
3
2
1
0
0
0
25
25
L
(at Maximum Ambient Operating
50
50
75
75
V
V
DD
C
C
DD
L
L
= 4.5V
– pF
– pF
= 4.5V
100
100
125
125
ADSP-216x
150
150
175
175
L