DS481 Datasheet, PDF (3/10 Pages) National Semiconductor (TI) – Low Power RS-485/RS-422 Multipoint Transceiver with Sleep Mode

Switching Characteristics
Over Supply Voltage and Operating Temperature Ranges, unless otherwise specified (Notes 5, 9, 10)
Symbol
Parameter
Conditions
Min Typ Max
t_PLHD
t_PHLD
t_SKEW
t_r
t_f
t_ZH
t_ZL
t_LZ
t_HZ
t_PSH
Driver Differential Propagation Delay — Low to High
Driver Differential Propagation Delay — High to Low
Differential Skew |t_PHLD − t_PLHD|
Driver Rise Time
Driver Fall Time
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable from Output Low
Driver Disable from Output High
Driver Enable from Sleep
Mode to Output High
R_L = 54Ω, C_L = 100 pF
C_L = 100 pF
C_L = 100 pF
C_L = 15 pF
C_L = 15 pF
C_L = 100 pF
(Note 12) (Figures 5, 6)
10 40 80
10 39 80
0 1 10
3 25 50
3 25 50
50 200
65 200
80 200
80 200
70 98 250
t_PSL
Driver Enable from Sleep
Mode to Output Low
C_L = 100 pF
(Note 12) (Figures 7, 8)
70 98 250
t_PLHD
t_PHLD
t_SKEW
t_ZH
t_ZL
t_LZ
t_HZ
t_PSH
Receiver Differential Propagation Delay — Low to High
Receiver Differential Propagation Delay — High to Low
Differential Skew |t_PHLD − t_PLHD|
Receiver Enable to Output High
Receiver Enable to Output Low
Receiver Disable from Output Low
Receiver Disable from Output High
Receiver Enable from Sleep
Mode to Output High
C_L = 15 pF (RO)
C_L = 15 pF
C_L = 15 pF
(Note 12) (Figures 11, 13)
30 190 400
30 210 400
0 20 50
45 150
40 150
50 150
55 150
70 97 250
t_PSL
Receiver Enable from Sleep
Mode to Output Low
C_L = 15 pF
(Note 12) (Figures 11, 12)
70 95 250
t_SLEEP Time to Sleep (Device)
DE = L and RE (Note 1) = H
50
600
(Figure 14)
f_max
Maximum Data Rate
(Note 11)
2.0
Units
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Mbps
Note 3: “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices
should be operated at these limits. The table of “Electrical Characteristics” specifies conditions of device operation.
Note 4: Current into device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground except V_OD1/2/3and
V_ID.
Note 5: All typicals are given for: V_CC = +5.0V, T_A = +25˚C.
Note 6: ∆|V_OD| and ∆|V_OC| are changes in magnitude of V _OD and V_OC respectively, that occur when the input changes state.
Note 7: I_IN2 includes the receiver input current and driver TRI-STATE leakage current.
Note 8: Supply current specification is valid for loaded transmitters when DE = 0V or enabled (DE = H) with no load.
Note 9: f = 1 MHz, t_r and t_f ≤ 6 ns, Z_O = 50Ω.
Note 10: C_L includes jig and probe capacitance.
Note 11: f_max is the guaranteed data rate for 50 ft of twisted pair cable. f _max may be conservatively determined from the ratio of driver transition time (t_r) to the data
rate unit interval (1/f_max). Using a 10% ratio yields f_max = (0.1)/50 ns = 2.0 Mb/s. Higher data rates may be supported by allowing larger ratios.
Note 12: For enable from sleep mode delays DE = L and RE (Note 1) = H for greater than 600 ns prior to test (device is in sleep mode).
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