MAX3291/MAX3292
RS-485/RS-422 Transceivers with Preemphasis
for High-Speed, Long-Distance Communication
4 _______________________________________________________________________________________
SWITCHING CHARACTERISTICS (continued)
(Typical Operating Circuit, V
CC
= +5V ±5%, R
PSET
= 0 (MAX3292), V
CC
= V
CCD
(MAX3292), T
A
= +25°C, unless otherwise noted.
Typical values are at V
CC
= +5V and T
A
= +25°C.)
Note 1: All currents into the device are positive; all currents out of the device are negative. All voltages are referenced to device
ground unless otherwise noted.
Note 2: Guaranteed by design.
Note 3: DPER is defined as (V
ODP
/ V
OD
).
Note 4: ∆V
ODP
and ∆V
OC
are the changes in V
DD
and V
OC
, respectively, when the DI input changes. This specification reflects
constant operating conditions. When operating conditions shift, the maximum value may be momentarily exceeded.
Note 5: ∆V
ODP
and ∆V
OC
are the changes in V
OD
and V
OC
, respectively, when the DI input changes state.
Note 6: Maximum current level applies to peak current just prior to foldback-current limiting; minimum current level applies during
current limiting.
Note 7: Shutdown is enabled by bringing RE high and DE low. If the enable inputs are in this state for less than 50ns, the device is
guaranteed not to enter shutdown. If the enable inputs are in this state for at least 500ns, the device is guaranteed to have
entered shutdown. Time to shutdown for the device (t
SHDN
) is measured by monitoring R0 as in Figure 4.
Figures 2 and 6, S2 closed, R
L
= 500Ω,
C
L
= 100pF
Figures 2 and 6, R
L
= 500Ω, C
L
= 100pF,
S2 closed
CONDITIONS
ns
ns6000 8750t
DZH(SHDN)
Driver Enable from Shutdown
to Output High
UNITSMIN TYP MAXSYMBOLPARAMETER
Figures 4 and 11 (Note 7) ns50 160 500t
SHDN
Time to Shutdown
Figures 2 and 8, R
L
= 1kΩ, C
L
= 100pF,
S1 closed
ns34355t
RZL
Receiver Enable to Output
Low
Figures 2 and 8, R
L
= 1kΩ, C
L
= 15pF,
S1 closed
ns
Figures 2 and 8, R
L
= 1kΩ, C
L
= 100pF,
S2 closed
25 45t
RLZ
Receiver Disable Time from
Low
ns34355t
RZH
Receiver Enable to Output
High
Figures 2 and 8, R
L
= 1kΩ, C
L
= 15pF,
S2 closed
ns25 45t
RHZ
Receiver Disable Time from
High
Figures 2 and 6, R
L
= 500Ω, C
L
= 100pF,
S1 closed
ns6000 8750t
DZL(SHDN)
Driver Enable from Shutdown
to Output Low
Figures 2 and 8, R
L
= 1kΩ, C
L
= 100pF,
S1 closed
ns30 1500t
RZL(SHDN)
Receiver Enable from
Shutdown to Output Low
Figures 2 and 8, R
L
= 1kΩ, C
L
= 100pF,
S2 closed
ns850 1500t
RZH(SHDN)
Receiver Enable from
Shutdown to Output High
Figures 7 and 9, C
L
= 100pF ns3t
RSKEW
Receiver Output Skew
t
RPLH
- t
RPHL
Driver Enable to Output High t
DZH
72 105
Figures 7 and 9, C
L
= 50pF, V
ID
= 2V,
V
CM
= 0
Receiver Propagation Delay
t
RPHL
52 85
ns
49 85t
RPLH
Figures 2 and 6, S2 closed, R
L
= 500Ω,
C
L
= 15pF
Driver Disable Time from High t
DHZ
71 100 ns
Figures 2 and 6, S1 closed, R
L
= 500Ω,
C
L
= 15pF
Driver Disable Time from Low t
DLZ
53 100 ns
Figures 2 and 6, S1 closed, R
L
= 500Ω,
C
L
= 100pF
Driver Enable to Output Low t
DZL
55 105 ns
