Datasheet

Rev. D | Page 75 of 88 | July 2013
ADSP-BF522/ADSP-BF523/ADSP-BF524/ADSP-BF525/ADSP-BF526/ADSP-BF527
TEST CONDITIONS
All Timing Requirements appearing in this data sheet were
measured under the conditions described in this section.
Figure 58 shows the measurement point for AC measurements
(except output enable/disable). The measurement point V
MEAS
is
V
DDEXT
/2 or V
DDMEM
/2 for V
DDEXT
/V
DDMEM
(nominal) = 1.8 V/
2.5 V/3.3 V.
Output Enable Time Measurement
Output balls are considered to be enabled when they have made
a transition from a high impedance state to the point when they
start driving.
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 59.
The time t
ENA_MEASURED
is the interval from when the reference
signal switches to when the output voltage reaches V
TRIP
(high)
or V
TRIP
(low). For V
DDEXT
/V
DDMEM
(nominal) = 1.8 V, V
TRIP
(high) is 1.05 V, and V
TRIP
(low) is 0.75 V. For V
DDEXT
/V
DDMEM
(nominal) = 2.5 V, V
TRIP
(high) is 1.5 V and V
TRIP
(low) is 1.0 V.
For V
DDEXT
/V
DDMEM
(nominal) = 3.3 V, V
TRIP
(high) is 1.9 V, and
V
TRIP
(low) is 1.4 V. Time t
TRIP
is the interval from when the out-
put 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:
If multiple balls (such as the data bus) are enabled, the measure-
ment value is that of the first ball to start driving.
Figure 55. Driver Type E Current (3.3V V
DDEXT
/V
DDMEM
)
Figure 56. Driver Type E Current (2.5V V
DDEXT
/V
DDMEM
)
Figure 57. Driver Type E Current (1.8V V
DDEXT
/V
DDMEM
)
0
SOURCE CURRENT (mA)
SOURCE VOLTAGE (V)
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
60
30
20
–60
–30
–10
V
OL
V
DDEXT
= 3.6V @ – 40 ° C
V
DDEXT
= 3.3V @ 25 ° C
–20
–40
10
40
V
DDEXT
= 3.0V @ 105 ° C
50
–50
3.0 3.5
0
SOURCE CURRENT (mA)
SOURCE VOLTAGE (V)
0 0.5 1.0 1.5 2.0 2.5
40
30
10
–40
–30
–10
V
OL
V
DDEXT
= 2.75V @ – 40 ° C
V
DDEXT
= 2.5V @ 25 ° C
20
–20
V
DDEXT
= 2.25V @ 105 ° C
3.5
0
SOURCE CURRENT (mA)
SOURCE VOLTAGE (V)
0 0.5 1.0 1.5
20
15
10
–20
–15
–5
V
OL
V
DDEXT
= 1.9V @ – 40 ° C
V
DDEXT
= 1.8V @ 25 ° C
–10
5
V
DDEXT
= 1.7V @ 105 ° C
3.02.52.0
Figure 58. Voltage Reference Levels for AC Measurements
(Except Output Enable/Disable)
Figure 59. Output Enable/Disable
INPUT
OR
OUTPUT
V
MEAS
V
MEAS
REFERENCE
SIGNAL
t
DIS
OUTPUT STARTS DRIVING
V
OH
(MEASURED) ⴚ ⌬V
V
OL
(MEASURED) + ⌬V
t
DIS_MEASURED
V
OH
(MEASURED)
V
OL
(MEASURED)
V
TRIP
(HIGH)
V
OH
(MEASURED
)
V
OL
(MEASURED)
HIGH IMPEDANCE STATE
OUTPUT STOPS DRIVING
t
ENA
t
DECAY
t
ENA_MEASURED
t
TRIP
V
TRIP
(LOW)
t
ENA
t
ENA_MEASURED
t
TRIP
–=