MAX3157
High CMRR RS-485 Transceiver
with ±50V Isolation
4 _______________________________________________________________________________________
SWITCHING CHARACTERISTICS (continued)
(V
CC
= +5V ±5%, YR = ZR = AR = BR = ISOCOM, C1 = C2 = 0.047µF, C3 = C4 = 1µF. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Driver Enable to Output High t
DZH
Figures 4 and 6, C
L
= 100pF, S2 closed 3500 ns
Driver Enable to Output Low t
DZL
Figures 4 and 6, C
L
= 100pF, S1 closed 3500 ns
Driver Disable Time from Low t
DLZ
Figures 4 and 6, C
L
= 15pF, S1 closed 300 ns
Driver Disable Time from High t
DHZ
Figures 4 and 6, C
L
= 15pF, S2 closed 300 ns
Receiver Input to Output
t
RPLH
,
t
RPHL
Figures 7 and 9; | V
ID
| ≥ 2.0V 440 600 ns
Differential Receiver Skew
|t
RPLH
- t
RPHL
|
t
RSKEW
Figures 7 and 9; | V
ID
| ≥ 2.0V 20 ns
Receiver Enable to Output Low t
RZL
Figures 2 and 8, C
L
= 100pF, S1 closed 20 50 ns
Receiver Enable to Output High t
RZH
Figures 2 and 8, C
L
= 100pF, S2 closed 20 50 ns
Receiver Disable Time from Low t
RLZ
Figures 2 and 8, C
L
= 100pF, S1 closed 200 500 ns
Receiver Disable Time from High t
RHZ
Figures 2 and 8, C
L
= 100pF, S2 closed 200 500 ns
Time to Shutdown t
SHDN
(Note 4) 50 200 700 ns
Driver Enable from Shutdown to
Output High
t
DZH
(SHDN)
Figures 4 and 6, C
L
= 15pF, S2
closed 0.2 1 ms
Driver Enable from Shutdown to
Output Low
t
DZL
(SHDN)
Figures 4 and 6, C
L
= 15pF, S1 closed 0.2 1 ms
Receiver Enable from Shutdown
to Output High
t
RZH
(SHDN)
Figures 2 and 8, C
L
= 100pF, S2 closed 0.2 1 m s
Receiver Enable from Shutdown
to Output Low
t
RZL
(SHDN)
Figures 2 and 8, C
L
= 100pF, S1 closed 0.2 1 ms
Charge-Pump Oscillating
Frequency
f
OSC
1.3 MHz
Note 1: All currents into the device are positive; all currents out of the device are negative. All voltages are referred to device
ground unless otherwise noted.
Note 2: ∆V
OD
and ∆V
OC
are the changes in V
OD
and V
OC
, respectively, when the DI input changes state.
Note 3: Current level applies to peak current just prior to foldback-current limiting.
Note 4: The device is put into shutdown 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 700ns, the device is guaran-
teed to have entered shutdown.
