
ADM2485
Rev. A | Page 5 of 20
TIMING SPECIFICATIONS
2.7 V ≤ VDD1 ≤ 5.5 V, 4.75 V ≤ VDD2 ≤ 5.25 V, TA = TMIN to TMAX, unless otherwise noted.
Table 2.
Parameter
Min
Typ
Max
Unit
Test Conditions/Comments
DRIVER
Maximum Data Rate
16
Mbps
Propagation Delay Input-to-Output
tPLH, tPHL
25
45
55
ns
RLDIFF = 54 Ω, CL1 = CL2 = 100 pF, see Figure 25 RTS-to-DE OUT Propagation Delay
20
35
55
ns
Driver Output-to-Output, tSKEW
2
5
ns
Rise/Fall Time, tR, tF
5
15
ns
Enable Time
43
53
ns
Disable Time
43
55
ns
Enable Skew, |tAZH tBZL|, |tAZL tBZH|
1
3
ns
Disable Skew, |tAHZ tBLZ|, |tALZ tBHZ|
2
5
ns
RECEIVER
Propagation Delay, tPLH, tPHL
25
45
55
ns
Differential Skew, tSKEW
5
ns
Enable Time
3
13
ns
Disable Time
3
13
ns
Timing Diagrams
06021-
012
tPHL
tPLH
3V
0V
VOUT
B
A
+VOUT
0V
–VOUT
1.5V
tF
tR
10% POINT
90% POINT
1/2VOUT
tSKEW = |tPLH – tPHL|
Figure 2. Driver Propagation Delay, Rise/Fall Timing
tSKEW = |tPLH – tPHL|
A – B
RxD
0V
1.5V
tPLH
tPHL
VOH
VOL
06
02
1
-01
3
Figure 3. Receiver Propagation Delay
VOH
VOH – 0.5V
VOL
VOH + 0.5V
tLZ
tZL
tHZ
tZH
A – B
RTS
0.7VDD1
0.3VDD1
0.5VDD1
2.3V
0V
06
02
1-
01
4
Figure 4. Driver Enable/Disable Timing
0.7VDD1
0.3VDD1
0.5VDD1
VOH
VOL
OUTPUT LOW
OUTPUT HIGH
tLZ
tZL
tHZ
tZH
VOH – 0.5V
VOH + 0.5V
1.5V
RxD
RE
0V
06
02
1-
01
5
Figure 5. Receiver Enable/Disable Timing