Datasheet

ADM2485
Rev. A | Page 5 of 20
TIMING SPECIFICATIONS
2.7 V ≤ V
DD1
≤ 5.5 V, 4.75 V ≤ V
DD2
≤ 5.25 V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Table 2.
Parameter Min Typ Max Unit Test Conditions/Comments
DRIVER
Maximum Data Rate 16 Mbps
Propagation Delay Input-to-Output
t
PLH
, t
PHL
25 45 55 ns R
LDIFF
= 54 Ω, C
L1
= C
L2
= 100 pF, see Figure 25
RTS-to-DE OUT Propagation Delay 20 35 55 ns See Figure 26
Driver Output-to-Output, t
SKEW
2 5 ns R
LDIFF
= 54 Ω, C
L1
= C
L2
= 100 pF, see Figure 2 and Figure 25
Rise/Fall Time, t
R
, t
F
5 15 ns R
LDIFF
= 54 Ω, C
L1
= C
L2
= 100 pF, see Figure 2 and Figure 25
Enable Time 43 53 ns See Figure 4 and Figure 27
Disable Time 43 55 ns See Figure 4 and Figure 27
Enable Skew, |t
AZH
− t
BZL
|, |t
AZL
− t
BZH
| 1 3 ns See Figure 4 and Figure 27
Disable Skew, |t
AHZ
− t
BLZ
|, |t
ALZ
− t
BHZ
| 2 5 ns See Figure 4 and Figure 27
RECEIVER
Propagation Delay, t
PLH
, t
PHL
25 45 55 ns C
L
= 15 pF, see Figure 3 and Figure 28
Differential Skew, t
SKEW
5 ns C
L
= 15 pF, see Figure 3 and Figure 28
Enable Time 3 13 ns R
L
= 1 kΩ, C
L
= 15 pF, see Figure 5 and Figure 29
Disable Time 3 13 ns R
L
= 1 kΩ, C
L
= 15 pF, see Figure 5 and Figure 29
Timing Diagrams
06021-012
t
PHL
t
PLH
3V
0V
V
OUT
B
A
+
V
OUT
0V
–
V
OUT
1.5V
1.5V
t
F
t
R
10% POINT
10% POINT
90% POINT
90% POINT
1/2V
OUT
t
SKEW
= |t
PLH
– t
PHL
|
Figure 2. Driver Propagation Delay, Rise/Fall Timing
t
SKEW
= |t
PLH
– t
PHL
|
A
– B
RxD
0V 0V
1.5V 1.5V
t
PLH
t
PHL
V
OH
V
OL
06021-013
Figure 3. Receiver Propagation Delay
V
OH
V
OH
– 0.5V
V
OL
V
OH
+ 0.5V
t
LZ
t
ZL
t
HZ
t
ZH
A
– B
A
– B
RTS
0.7V
DD1
0.3V
DD1
0.5V
DD1
0.5V
DD1
2.3V
2.3V
0V
06021-014
Figure 4. Driver Enable/Disable Timing
0.7
V
DD1
0.3V
DD1
0.5V
DD1
0.5V
DD1
V
OH
V
OL
OUTPUT LOW
OUTPUT HIGH
t
LZ
t
ZL
t
HZ
t
ZH
V
OH
– 0.5V
V
OH
+ 0.5V
1.5V
1.5V
RxD
RxD
RE
0V
06021-015
Figure 5. Receiver Enable/Disable Timing