LTC2872
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= V
L
= 3.3V, TE485_1 = TE485_2 = 0V, LB = 0V unless otherwise
noted. V
L
≤ V
CC
.
SYMBOL
PARAMETER
Maximum Data Rate
t
PLHD485
t
PHLD485
Driver Propagation Delay
Driver Propagation Delay Difference
|t
PLHD485
– t
PHLD485
|
t
SKEWD485
t
RD485
, t
FD485
t
ZLD485
, t
ZHD485
,
t
LZD485
, t
HZD485
t
ZHSD485
, t
ZLSD485
t
PLHR485
, t
PHLR485
t
SKEWR485
t
RR485
, t
FR485
t
ZLR485
, t
ZHR485
t
LZR485
, t
HZR485
t
RTEN485
, t
RTZ485
Driver Skew (Y to Z)
Driver Rise or Fall Time
Driver Output Enable or Disable Time
Driver Enable from Shutdown
Receiver Input to Output
Differential Receiver Skew
|t
PLHR485
– t
PHLR485
|
Receiver Output Rise or Fall Time
Receiver Output Enable or Disable Time
Termination Enable or Disable Time
Maximum Data Rate
Driver Slew Rate (Figure 9)
t
PHLD232
, t
PLHD232
t
SKEWD232
t
ZLD232
, t
ZHD232
t
LZD232
, t
HZD232
t
PHLR232
, t
PLHR232
t
SKEWR232
t
RR232
, t
FR232
t
ZLR232
, t
ZHR232
,
t
LZR232
, t
HZR232
Driver Propagation Delay
Driver Skew
Driver Output Enable or Disable Time
Receiver Propagation Delay
Receiver Skew
Receiver Rise or Fall Time
Receiver Output Enable or Disable Time
CONDITIONS
(Note 3)
R
DIFF
= 54Ω, C
L
= 100pF (Figure 4)
R
DIFF
= 54Ω, C
L
= 100pF (Figure 4)
R
DIFF
= 54Ω, C
L
= 100pF (Figure 4)
R
DIFF
= 54Ω, C
L
= 100pF (Figure 4)
FEN = V
L
, R
L
= 500Ω, C
L
= 50pF (Figure 5)
FEN = 0V, R
L
= 500Ω, C
L
= 50pF (Figure 5)
C
L
= 15pF V
CM
= 1.5V, |A–B| = 1.5V, (Figure 6)
,
(Note 5)
C
L
= 15pF (Figure 6)
C
L
= 15pF (Figure 6)
FEN = V
L
, R
L
= 1k, C
L
= 15pF (Figure 7)
FEN = V
L
, V
B
= 0V, V
AB
= 2V (Figure 8) (Note 5)
,
R
L
= 3kΩ, C
L
= 2500pF
R
L
= 3kΩ, C
L
= 500pF (Note 3)
R
L
= 3kΩ, C
L
= 2500pF
R
L
= 3kΩ, C
L
= 50pF
R
L
= 3kΩ, C
L
= 50pF (Figure 9)
R
L
= 3kΩ, C
L
= 50pF (Figure 9)
FEN = V
L
, R
L
= 3kΩ, C
L
= 50pF (Figure 10)
C
L
= 150pF (Figure 11)
C
L
= 150pF (Figure 11)
C
L
= 150pF (Figure 11)
FEN = V
L
, R
L
= 1kΩ, C
L
= 150pF (Figure 12)
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
swiTching characTerisTics
MIN
20
TYP
MAX
UNITS
Mbps
RS485 AC Characteristics
20
1
1.5
7.6
70
6
±8
15
120
0.2
55
1
3
30
2
85
9
15
85
100
100
500
4
1
50
0.4
60
25
60
0.7
200
2
2
200
30
2
ns
ns
ns
ns
ns
ms
ns
ns
ns
ns
µs
kbps
kbps
V/µs
V/µs
µs
ns
µs
ns
ns
ns
µs
RS232 AC Characteristics
l
l
l
l
l
Power Supply Generator
V
DD
/V
EE
Supply Rise Time
FEN =
, (Notes 3 and 4)
l
0.2
2
ms
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2.
All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to device ground unless
otherwise specified.
Note 3.
Guaranteed by other measured parameters and not tested directly.
Note 4.
Time from FEN until V
DD
≥ 5V and V
EE
≤ –5V. External
components as shown in typical application.
Note 5.
Condition applies to A, B for H/F = 0V, and Y, Z for H/F = V
L
.
Note 6.
This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions.
Overtemperature protection activates at a junction temperature exceeding
150°C. Continuous operation above the specified maximum operating
junction temperature may result in device degradation or failure.
Note 7.
Guaranteed by design and not subject to production test.
2872f
5
LINEAR [ LINEAR INTEGRATED SYSTEMS ]
