Datasheet

60
0
80
ADSP-BF561
POWER DISSIPATION
Many operating conditions can affect power dissipation. System
designers should refer to Estimating Power for ADSP-BF561
60
80
100
40
20
0
–20
–40
–60
–80
–100
SOURCE CURRENT (mA)
V
OH
V
DDEXT
= 2.95V
V
DDEXT
= 3.30V
V
DDEXT
= 3.65V
V
OL
Blackfin Processors (EE-293) on the Analog Devices website
(www.analog.com)—use site search on “EE-293.” This docu-
ment provides detailed information for optimizing your design
for lowest power.
See the ADSP-BF561 Blackfin Processor Hardware Reference
Manual for definitions of the various operating modes and for
instructions on how to minimize system power.
TEST CONDITIONS
All timing parameters appearing in this data sheet were mea-
sured under the conditions described in this section. Figure 37
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
shows the measurement point for ac measurements (except out-
SOURCE VOLTAGE (V)
put enable/disable). The measurement point V
MEAS
is 1.5 V for
Figure 34. Drive Current C (High V
DDEXT
)
V
DDEXT
(nominal) = 2.5 V/3.3 V.
100
V
DDEXT
= 2.75V
V
DD
V
DDEXT
EXT
= 2.25V
= 2.50V
V
OH
V
OL
INPUT
OR
OUTPUT
V
MEAS
V
MEAS
Figure 37. Voltage Reference Levels for AC
Measurements (Except Output Enable/Disable)
Output Enable Time Measurement
Output pins are considered to be enabled when they have made
SOURCE CURRENT (mA)
40
20
–20
–40
–60
–80
a transition from a high impedance state to the point when they
start driving.
–100
0
0.5 1.0 1.5 2.0 2.5 3.0
SOURCE VOLTAGE (V)
The output enable time t
ENA
is the interval from the point when a
reference signal reaches a high or low voltage level to the point
when the output starts driving as shown on the right side of
Figure 35. Drive Current D (Low V
DDEXT
)
Figure 38 on Page 43.
The time t
ENA _ MEASURED
is the interval, from when the reference sig-
150
100
50
0
–50
–100
–150
SOURCE CURRENT (mA)
V
OH
V
OL
V
DDEXT
= 2.95V
V
DDEXT
= 3.30V
V
DDEXT
= 3.65V
nal switches, to when the output voltage reaches V
TRIP
(high) or
V
TRIP
(low). V
TRIP
(high) is 2.0 V and V
TRIP
(low) is 1.0 V for V
DDEXT
(nominal) = 2.5 V/3.3 V. Time t
TRIP
is the interval from when the
output starts driving to when the output reaches the V
TRIP
(high)
or V
TRIP
(low) trip voltage.
Time t
ENA
is calculated as shown in the equation:
= –t
ENA
t
ENA_MEASURED
t
TRIP
If multiple pins (such as the data bus) are enabled, the measure-
ment value is that of the first pin to start driving.
Output Disable Time Measurement
Output pins are considered to be disabled when they stop driv-
ing, go into a high impedance state, and start to decay from their
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
SOURCE VOLTAGE (V)
output high or low voltage. The output disable time t
DIS
is the
difference between t
DIS _ MEASURED
and t
DECAY
as shown on the left side
Figure 36. Drive Current D (High V
DDEXT
)
of Figure 38 on Page 43.
= –t
DIS
t
DIS_MEASURED
t
DECAY
Rev. E | Page 42 of 64 | September 2009