ADSP-2171 Analog Devices, ADSP-2171 Datasheet - Page 43

• Manufacturer Part Number: ADSP-2171
• Description: ADSP-2100 Family DSP Microcomputers
• Manufacturer: Analog Devices

REV. A
ADSP-2173
ENVIRONMENTAL CONDITIONS
Ambient Temperature Rating:
Package
TQFP
PQFP
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:
•
•
•
•
P
graph (Figure 18).
(C
Address, DMS
Data Output, WR 9
RD
CLKOUT
Total power dissipation for this example is P
INT
T
T
PD = Power Dissipation in W
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
CA
JA
JC
AMB
CASE
= internal power dissipation from Power vs. Frequency
V
= Thermal Resistance (Junction-to-Ambient)
= Thermal Resistance (Junction-to-Case)
= Thermal Resistance (Case-to-Ambient)
DD
Total Power Dissipation = P
= T
= Case Temperature in C
2
CASE
f ) is calculated for each output:
– (PD
# of
Pins
8
1
1
50 C/W
41 C/W
JA
C
10 pF
10 pF
10 pF
10 pF
C
CA
)
V
DD
DD
V
3.3
3.3
3.3
3.3
2
DD
= 3.3 V and t
INT
2
2
2
2
2 C/W
10 C/W
2
V
V
V
V
JC
f
+ (C
f
20 MHz
10 MHz
10 MHz
20 MHz
INT
V
DD
CK
+ 30.5 mW.
2
= 50 ns.
= 17.4 mW
=
=
=
f )
48 C/W
31 C/W
30.5 mW
CA
9.8 mW
1.1 mW
2.2 mW
–43–
ADSP-2171/ADSP-2172/ADSP-2173
VALID FOR ALL TEMPERATURE GRADES.
1
2
3
OF IDLE n INSTRUCTION (CLOCK FREQUENCY REDUCTION).
EXECUTION OF IDLE INSTRUCTION. DEASSERTED PINS ARE
DRIVEN TO EITHER V
OPERATING WITH CLKOUT DISABLED.
POWER REFLECTS DEVICE OPERATING WITH CLKOUT DISABLED.
POWER REFLECTS DEVICE OPERATING WITH NO OUTPUT LOADS.
IDLE REFERS TO ADSP-2173 STATE OF OPERATION DURING
TYPICAL POWER DISSIPATION AT 3.3V V
90
85
80
75
70
65
60
55
50
45
40
35
20
19
18
17
16
15
14
13
12
11
10
16
15
14
13
12
11
10
9
9
8
7
6
5
15.5 mW
11.8 mW
11.8 mW
55 mW
32 mW
44 mW
6.2 mW
8.5 mW
6.8 mW
12
12
12
Figure 34. Power vs. Frequency
13
13
13
POWER, IDLE n MODES
POWER, INTERNAL
14
14
14
POWER, IDLE
DD
1
OR GND. POWER REFLECTS DEVICE
1
1
15
15
15
/ t
/ t
/ t
CK
CK
CK
16
16
16
– MHz
– MHz
– MHz
17
17
17
1, 2
18
18
18
1
DD
DURING EXECUTION
19
19
19
3
16.2 mW
16.2 mW
20.5 mW
12.7 mW
7.2 mW
71 mW
7.8 mW
89 mW
57 mW
20
20
20
IDLE;
IDLE (16)
IDLE (128)