adsp-2186bca-160 Analog Devices, Inc., adsp-2186bca-160 Datasheet - Page 27

• Manufacturer Part Number: adsp-2186bca-160
• Description: Dsp Microcomputer
• Manufacturer: Analog Devices, Inc.

REV. A
OUTPUT DRIVE CURRENTS
Figure 22 shows typical I-V characteristics for the output drivers
of the ADSP-2186. The curves represent the current drive
capability of the output drivers as a function of output voltage.
POWER DISSIPATION
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 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
• 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
graph (Figure 23).
(C
Address, DMS
Data Output, WR 9
RD
CLKOUT
Total power dissipation for this example is PINT + 140 mW.
INT
address pins switching.
50% of the data pins switching.
= internal power dissipation from Power vs. Frequency
V
DD
–20
–40
–60
–80
60
40
20
Total Power Dissipation = P
2
0
0
V
f) is calculated for each output:
OH
Figure 22. Typical Drive Currents
1
# of
Pins
8
1
1
SOURCE VOLTAGE – Volts
2
C V
10 pF
10 pF
10 pF
10 pF
C
4.5V, +85 C
5.5V, –40 C
DD
DD
3
2
= 5.0 V and t
5
5
5
5
INT
V
2
2
2
2
DD
f
V
V
V
V
+ (C
2
4.5V, +85 C
5.0V, +25 C
5.5V, –40 C
4
5.0V, +25 C
f
40 MHz = 80 mW
20 MHz = 45 mW
20 MHz =
40 MHz = 10 mW
V
DD
CK
5
2
= 30 ns.
V
f)
OL
140 mW
6
5 mW
–27–
VALID FOR ALL TEMPERATURE GRADES.
1
2
3
4
POWER REFLECTS DEVICE OPERATING WITH NO OUTPUT LOADS.
TYPICAL POWER DISSIPATION AT 5.0V V
I
MEMORY. 50% OF THE INSTRUCTIONS ARE MULTIFUNCTION (TYPES 1, 4, 5, 12, 13, 14),
30% ARE TYPE 2 AND TYPE 6, AND 20% ARE IDLE INSTRUCTIONS.
IDLE REFERS TO ADSP-2186 STATE OF OPERATION DURING EXECUTION OF IDLE
INSTRUCTION. DEASSERTED PINS ARE DRIVEN TO EITHER V
DD
MEASUREMENT TAKEN WITH ALL INSTRUCTIONS EXECUTING FROM INTERNAL
100
500
400
300
200
100
80
60
40
20
80
60
40
20
0
0
0
34.7mW
32.8mW
330mW
250mW
180mW
62mW
82mW
62mW
45mW
Figure 23. Power vs. Frequency
2186 POWER, INTERNAL
33.33
33.33
33.33
POWER, IDLE n MODES
V
V
V
V
V
V
DD
POWER, IDLE
DD
DD
DD
DD
DD
= 5.5V
= 5.5V
= 5.0V
= 4.5V
= 4.5V
= 5.0V
1/tcyc – MHz
1/tcyc – MHz
1/tcyc – MHz
DD
AND T
70.5mW
36.6mW
34.3mW
1,2,4
A
= +25 C EXCEPT WHERE SPECIFIED.
40
40
40
1,2,3
ADSP-2186
2
385mW
300mW
225mW
91.5mW
70.5mW
52mW
IDLE
IDLE (16)
IDLE (128)
DD
OR GND.