Datasheet

ADSP-TS203S
Rev. D | Page 35 of 48 | May 2012
TEST CONDITIONS
The ac signal specifications (timing parameters) appear in
Table 29 on Page 27. These include output disable time, output
enable time, and capacitive loading. The timing specifications
for the processor apply for the voltage reference levels in
Figure 32.
Output Disable Time
Output pins are considered to be disabled when they stop driv-
ing, go into a high impedance state, and start to decay from their
output high or low voltage. The time for the voltage on the bus
to decay by ΔV is dependent on the capacitive load, C
L
and the
load current, I
L
. This decay time can be approximated by the
following equation:
The output disable time t
DIS
is the difference between
t
MEASURED_DIS
and t
DECAY
as shown in Figure 33. The time
t
MEASURED_DIS
is the interval from when the reference signal
switches to when the output voltage decays ΔV from the mea-
sured output high or output low voltage. t
DECAY
is calculated
with test loads C
L
and I
L
, and with ΔV equal to 0.4 V.
Figure 28. Typical Drive Currents at Strength 4
Figure 29. Typical Drive Currents at Strength 5
Figure 30. Typical Drive Currents at Strength 6
OUTPUT PIN VOLTAGE (V)
02.80.4 0.8 1.2 1.6 2.0 2.4
O
U
T
P
U
T
P
I
N
C
U
R
R
E
N
T
(
m
A
)
–10
0
10
V
DD_IO
= 2.38V, +105°C
–20
–30
–40
–60
20
30
40
60
70
STRENGTH 4
V
DD_IO
=2.5V,+25°C
V
DD_IO
=2.63V,–40°C
I
OL
I
OH
V
DD_IO
= 2.38V, +105°C
V
DD_IO
=2.5V,+25°C
V
DD_IO
=2.63V,–40°C
50
–50
–70
OUTPUT PIN VOLTAGE (V)
02.80.4 0.8 1.2 1.6 2.0 2.4
O
U
T
P
U
T
P
I
N
C
U
R
R
E
N
T
(
m
A
)
–11
0
11
V
DD_IO
= 2.38V, +105°C
–22
–33
–44
–66
22
33
44
66
88
STRENGTH 5
V
DD_IO
=2.5V,+25°C
V
DD_IO
= 2.63V, –40°C
I
OL
I
OH
V
DD_IO
= 2.38V, +105°C
V
DD_IO
=2.5V,+25°C
V
DD_IO
= 2.63V, –40°C
77
55
–55
–88
–77
OUTPUT PIN VOLTAGE (V)
02.80.4 0.8 1.2 1.6 2.0 2.4
O
U
T
P
U
T
P
I
N
C
U
R
R
E
N
T
(
m
A
)
0
10
20
V
DD_IO
= 2.38V, +105°C
–10
–20
–30
–40
–100
30
40
50
60
100
STRENGTH 6
V
DD_IO
=2.5V,+25°C
V
DD_IO
= 2.63V, –40°C
I
OL
I
OH
V
DD_IO
=2.38V,+105°C
V
DD_IO
=2.5V,+25°C
V
DD_IO
= 2.63V, –40°C
70
80
90
–50
–60
–70
–80
–90
Figure 31. Typical Drive Currents at Strength 7
Figure 32. Voltage Reference Levels for AC Measurements
(Except Output Enable/Disable)
OUTPUT PIN VOLTAGE (V)
02.80.4 0.8 1.2 1.6 2.0 2.4
O
U
T
P
U
T
P
I
N
C
U
R
R
E
N
T
(
m
A
)
–10
0
10
V
DD_IO
= 2.38V, +105°C
–20
–30
–40
–50
–110
20
30
40
50
110
STRENGTH 7
V
DD_IO
=2.5V,+25°C
V
DD_IO
= 2.63V, –40°C
I
OL
I
OH
V
DD_IO
= 2.38V, +105°C
V
DD_IO
=2.5V,+25°C
V
DD_IO
=2.63V,–40°C
60
70
80
90
100
–60
–70
–80
–90
–100
INPUT
OR
OUTPUT
1.25V 1.25V
t
DECAY
C
L
VΔ()I
L
⁄=