ADSP-21371KSWZ-2A2 View Datasheet(PDF) - Analog Devices
Part Name
Description
MFG CO.
'ADSP-21371KSWZ-2A2' PDF : 52 Pages View PDF
OUTPUT DRIVE CURRENTS
Figure 35 shows typical I-V characteristics for the output driv-
ers of the processors. The curves represent the current drive
capability of the output drivers as a function of output voltage.
40
30
20
10
0
- 10
- 20
- 30
- 40
0
VOH
3.11V, 125°C
3.3V, 25°C
3.47V, -45°C
VOL
0.5
3.11V, 125°C
3.3V, 25°C
3.47V, -45°C
1.0
1.5 2.0
2.5
3.0
3.5
SWEEP (VDDEXT) VOLTAGE (V)
Figure 35. Typical Drive at Junction Temperature
TEST CONDITIONS
The ac signal specifications (timing parameters) appear in
Table 15 on Page 21 through Table 41 on Page 44. These include
output disable time, output enable time, and capacitive loading.
The timing specifications for the SHARC apply for the voltage
reference levels in Figure 36.
Timing is measured on signals when they cross the 1.5 V level as
described in Figure 37. All delays (in nanoseconds) are mea-
sured between the point that the first signal reaches 1.5 V and
the point that the second signal reaches 1.5 V.
TO
OUTPUT
PIN
ȍ
30pF
VLOAD
Figure 36. Equivalent Device Loading for AC Measurements
(Includes All Fixtures)
INPUT
OR 1.5V
OUTPUT
1.5V
Figure 37. Voltage Reference Levels for AC Measurements
ADSP-21371/ADSP-21375
CAPACITIVE LOADING
Output delays and holds are based on standard capacitive loads:
30 pF on all pins (see Figure 36). Figure 40 shows graphically
how output delays and holds vary with load capacitance. The
graphs of Figure 38, Figure 39, and Figure 40 may not be linear
outside the ranges shown for Typical Output Delay vs. Load
Capacitance and Typical Output Rise Time (20% to 80%,
V = Min) vs. Load Capacitance.
12
10
y = 0.0467x + 1.6323
RISE
FALL
8
6
4
y = 0.045x + 1.524
2
0
0
50
100
150
200
250
LOAD CAPACITANCE (pF)
Figure 38. Typical Output Rise/Fall Time (20% to 80%,
VDDEXT = Max)
12
RISE
10
y = 0.049x + 1.5105
FALL
8
6
y = 0.0482x + 1.4604
4
2
0
0
50
100
150
200
250
LOAD CAPACITANCE (pF)
Figure 39. Typical Output Rise/Fall Time (20% to 80%,
VDDEXT = Min)
Rev. C | Page 45 of 52 | September 2009
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