LTC2850 Datasheet, PDF (5/16 Pages) Linear Technology – 3.3V 20Mbps RS485/RS422 Transceivers

LTC2850/LTC2851/LTC2852
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_CC = 3.3V unless otherwise noted. (Note 2)
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Supplies
I_CCS
Supply Current in Shutdown Mode
DE = 0V, RE = V_CC,
l
LTC2850, LTC2852 (C and I-Grade)
LTC2850, LTC2852 (H-Grade)
l
I_CCR
Supply Current in Receive Mode
I_CCT
Supply Current in Transmit Mode
DE = 0V, RE = 0V (LTC2850, LTC2852)
l
No Load, DE = V_CC, RE = V_CC (LTC2850,
l
LTC2852)
I_CCTR
Supply Current with Both Driver and
No Load, DE = V_CC, RE = 0V
l
Receiver Enabled
0
5
μA
0
15
μA
370
900
μA
450 1000
μA
450 1000
μA
SWITCHING CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_CC = 3.3V, unless otherwise noted. (Note 2)
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Driver
f_MAX
Maximum Data Rate
t_PLHD, t_PHLD Driver Input to Output
Δt_PD
Driver Input to Output Difference
|t_PLHD – t_PHLD|
t_SKEWD
Driver Output Y to Output Z
t_RD, t_FD
Driver Rise or Fall Time
t_ZLD, t_ZHD, Driver Enable or Disable Time
t_LZD, t_HZD
t_ZHSD, t_ZLSD Driver Enable from Shutdown
t_SHDN
Time to Shutdown
(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)
R_L = 500Ω, C_L = 50pF, RE = 0V (Figure 5)
(LTC2850, LTC2852)
R_L = 500Ω, C_L = 50pF, RE = V_CC (Figure 5)
(LTC2850, LTC2852)
R_L
or
= 500Ω,
(DE = 0V,
C_RLE==5_↑0)p(F,F(igDuEre=
↓,
5)
RE = V_CC)
(LTC2850,
LTC2852)
l 20
l
l
l
l
l
l
l
Mbps
10
50
ns
1
6
ns
1
±6
ns
4
12.5
ns
70
ns
8
μs
100
ns
Receiver
t_PLHR, t_PHLR Receiver Input to Output
t_SKEWR
t_RR, t_FR
t_ZLR, t_ZHR,
t_LZR, t_HZR
t_ZHSR, t_ZLSR
Differential Receiver Skew
|t_PLHR – t_PHLR|
Receiver Output Rise or Fall Time
Receiver Enable/Disable
Receiver Enable from Shutdown
C_L = 15pF, V_CM = 1.5V, |V_AB| = 1.5V,
l
t_R and t_F < 4ns (Figure 6)
C_L = 15pF (Figure 6)
l
C_L = 15pF (Figure 6)
l
R_L =1k, C_L =15pF, DE = V_CC (Figure 7)
l
(LTC2850, LTC2852)
R_L = 1k, C_L = 15pF, DE = 0V (Figure 7)
l
(LTC2850, LTC2852)
50
70
ns
1
6
ns
3
12.5
ns
50
ns
8
μs
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. High temperatures degrade operating lifetimes.
Operating lifetime is derated at temperatures greater than 105°C.
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: Maximum data rate is guaranteed by other measured parameters
and is not tested directly.
Note 4: 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.
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