adsp-21483 Analog Devices, Inc., adsp-21483 Datasheet - Page 56

• Manufacturer Part Number: adsp-21483
• Description: Sharc Processor
• Manufacturer: Analog Devices, Inc.

ADSP-21483/21486/21487/21488/21489
OUTPUT DRIVE CURRENTS
Figure 43
ers of the ADSP-2148x. The curves represent the current drive
capability of the output drivers as a function of output voltage.
TEST CONDITIONS
The ac signal specifications (timing parameters) appear in
Table 16 on Page 24
output disable time, output enable time, and capacitive loading.
The timing specifications for the SHARC apply for the voltage
reference levels in
Timing is measured on signals when they cross the 1.5 V level as
described in
sured between the point that the first signal reaches 1.5 V and
the point that the second signal reaches 1.5 V.
12
10
V
8
6
4
2
0
LOAD
NOTES:
THE WORST CASE TRANSMISSION LINE DELAY IS SHOWN AND CAN BE USED
FOR THE OUTPUT TIMING ANALYSIS TO REFELECT THE TRANSMISSION LINE
EFFECT AND MUST BE CONSIDERED. THE TRANSMISSION LINE (TD), IS FOR
LOAD ONLY AND DOES NOT AFFECT THE DATA SHEET TIMING SPECIFICATIONS.
ANALOG DEVICES RECOMMENDS USING THE IBIS MODEL TIMING FOR A GIVEN
SYSTEM REQUIREMENT. IF NECESSARY, A SYSTEM MAY INCORPORATE
EXTERNAL DRIVERS TO COMPENSATE FOR ANY TIMING DIFFERENCES.
4pF
0
Figure 44. Equivalent Device Loading for AC Measurements
50Ω
shows typical I-V characteristics for the output driv-
Figure 43. Typical Drive at Junction Temperature
Figure
70Ω
50Ω
400Ω
50
2pF
Figure
45. All delays (in nanoseconds) are mea-
through
TBD
45Ω
0.5pF
100
(Includes All Fixtures)
TESTER PIN ELECTRONICS
44.
Table 48 on Page
ZO = 50Ω (impedance)
TD = 4.04 ± 1.18 ns
150
T1
200
55. These include
OUTPUT
DUT
250
Rev. PrA | Page 56 of 66 | March 2010
CAPACITIVE LOADING
Output delays and holds are based on standard capacitive loads:
30 pF on all pins (see
how output delays and holds vary with load capacitance. The
graphs of
outside the ranges shown for Typical Output Delay vs. Load
Capacitance and Typical Output Rise Time (20% to 80%,
V = Min) vs. Load Capacitance.
OUTPUT
12
10
12
10
INPUT
8
6
4
2
0
8
6
4
2
0
OR
0
0
Figure 45. Voltage Reference Levels for AC Measurements
Figure
Figure 46. Typical Output Rise/Fall Time (20% to 80%,
Figure 47. Typical Output Rise/Fall Time (20% to 80%,
1.5V
50
50
46,
Preliminary Technical Data
Figure
Figure
TBD
TBD
100
100
V
V
DD_EXT
DD_EXT
47, and
44).
150
150
= Max)
= Min)
Figure 48
Figure 48
200
200
shows graphically
may not be linear
1.5V
250
250