LINER LTC485IN8 Low power rs485 interface transceiver Datasheet

LTC485
Low Power RS485
Interface Transceiver
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FEATURES
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DESCRIPTIO
Low Power: ICC = 300µA Typ
Designed for RS485 Interface Applications
Single 5V supply
– 7V to 12V Bus Common Mode Range Permits
±7V Ground Difference Between Devices on the Bus
Thermal Shutdown Protection
Power-Up/Down Glitch-Free Driver Outputs
Permit Live Insertion or Removal of Transceiver
Driver Maintains High Impedance in Three-State
or with the Power Off
Combined Impedance of a Driver Output and
Receiver Allows Up to 32 Transceivers on the Bus
70mV Typical Input Hysteresis
30ns Typical Driver Propagation Delays
with 5ns Skew
Pin Compatible with ±60V Protected LT1785 and
52Mbps LTC1685
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APPLICATIO S
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The CMOS design offers significant power savings over its
bipolar counterpart without sacrificing ruggedness against
overload of ESD damage.
The driver and receiver feature three-state outputs, with
the driver outputs maintaining high impedance over the
entire common mode range. Excessive power dissipation
caused by bus contention or faults is prevented by a
thermal shutdown circuit which forces the driver outputs
into a high impedance state.
The receiver has a fail-safe feature which guarantees a
high output state when the inputs are left open.
The LTC485 is fully specified over the commercial and
extended industrial temperature range.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Low Power RS485/RS422 Transceiver
Level Translator
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The LTC®485 is a low power differential bus/line transceiver designed for multipoint data transmission standard
RS485 applications with extended common mode range
(12V to – 7V). It also meets the requirements of RS422.
TYPICAL APPLICATIO
Driver Outputs
RO1
R
VCC1
RE1
Rt
A
DE1
DI1
D
GND1
Rt
RO2
R
VCC2
RE2
DE2
DI2
B
D
GND2
LTC485 • TA01
LTC485 • TA02
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LTC485
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ABSOLUTE
PACKAGE/ORDER I FOR ATIO
(Note 1)
Supply Voltage ....................................................... 12V
Control Input Voltages ................... – 0.5V to VCC + 0.5V
Driver Input Voltage ....................... – 0.5V to VCC + 0.5V
Driver Output Voltage ........................................... ±14V
Receiver Input Voltage .......................................... ±14V
Receiver Output Voltages .............. – 0.5V to VCC + 0.5V
Operating Temperature Range
LTC485I ...................................... – 40°C ≤ TA ≤ 85°C
LTC485C ......................................... 0°C ≤ TA ≤ 70°C
LTC485M (OBSOLETE) .......... – 55°C ≤ TA ≤ 125°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
TOP VIEW
RO 1
R
RE 2
DE 3
D
DI 4
N8 PACKAGE
8-LEAD PLASTIC DIP
8
VCC
7
B
6
A
5
GND
S8 PACKAGE
8-LEAD PLASTIC SOIC
LTC485CN8
LTC485CS8
LTC485IN8
LTC485IS8
S8 PART MARKING
TJMAX = 125°C, θJA = 100°C/ W (N)
TJMAX = 150°C, θJA = 150°C/ W (S)
485
485I
ORDER PART
NUMBER
J8 PACKAGE
8-LEAD CERAMIC DIP
TJMAX = 155°C, θJA = 100°C/ W (J)
LTC485CJ8
LTC485MJ8
OBSOLETE PACKAGE
Consider the N8 Package for Alternate Source
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 5V ±5%, unless otherwise noted. (Notes 2 and 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
VOD1
Differential Driver Output Voltage (Unloaded)
IO = 0
●
VOD2
Differential Driver Output Voltage (with Load)
R = 50Ω (RS422)
R = 27Ω (RS485), Figure 1
●
●
TYP
2
1.5
MAX
UNITS
5
V
5
V
V
∆VOD
Change in Magnitude of Driver Differential
Output Voltage for Complementary States
R = 27Ω or R = 50Ω, Figure 1
●
0.2
V
VOC
Driver Common Mode Output Voltage
R = 27Ω or R = 50Ω, Figure 1
●
3
V
∆⏐VOC⏐
Change in Magnitude of Driver Common-Mode
Output Voltage for Complementary States
R = 27Ω or R = 50Ω, Figure 1
●
0.2
V
VIH
Input High Voltage
DE, DI, RE
●
VIL
Input Low Voltage
DE, DI, RE
●
0.8
V
IIN1
Input Current
DE, DI, RE
●
±2
µA
IIN2
Input Current (A, B)
DE = 0, VCC = 0V
or 5.25V
2
V
VIN = 12V
●
±1
mA
VIN = – 7V
●
– 0.8
mA
0.2
V
VTH
Differential Input Threshold Voltage
for Receiver
– 7V ≤ VCM ≤ 12V
●
∆VTH
Receiver Input Hysteresis
VCM = 0V
●
VOH
Receiver Output High Voltage
IO = – 4mA, VID = 200mV
●
VOL
Receiver Output Low Voltage
IO = 4mA, VID = – 200mV
●
0.4
V
IOZR
Three-State (High Impedance) Output
Current at Receiver
VCC = Max, 0.4V ≤ VO ≤ 2.4V
●
±1
µA
RIN
Receiver Input Resistance
– 7V ≤ VCM ≤ 12V
●
– 0.2
70
mV
3.5
12
V
kΩ
sn485 LTC485ffs
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LTC485
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SWITCHI G CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C.VCC = 5V ±5%, unless otherwise noted. (Notes 2 and 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
ICC
Supply Current
No Load, Pins 2,
3, 4 = 0V or 5V
TYP
MAX
UNITS
Outputs Enabled
●
500
900
µA
Outputs Disabled
●
300
500
µA
IOSD1
Driver Short-Circuit Current, VOUT = HIGH
VO = – 7V
●
35
100
250
mA
IOSD2
Driver Short-Circuit Current, VOUT = LOW
VO = 10V
●
35
100
250
mA
IOSR
Receiver Short-Circuit Current
0V ≤ VO ≤ VCC
●
7
85
mA
tPLH
Driver Input to Output
●
10
30
50
ns
tPHL
Driver Input to Output
RDIFF = 54Ω, CL1 = CL2 = 100pF,
(Figures 3 and 5)
●
10
30
50
ns
tSKEW
Driver Output to Output
●
5
10
ns
tr, tf
Driver Rise or Fall Time
●
15
25
ns
tZH
Driver Enable to Output High
CL = 100pF (Figures 4 and 6) S2 Closed
●
40
70
ns
tZL
Driver Enable to Output Low
CL = 100pF (Figures 4 and 6) S1 Closed
●
40
70
ns
tLZ
Driver Disable Time from Low
CL = 15pF (Figures 4 and 6) S1 Closed
●
40
70
ns
tHZ
Driver Disable Time from High
CL = 15pF (Figures 4 and 6) S2 Closed
●
40
70
ns
tPLH
Receiver Input to Output
RDIFF = 54Ω, CL1 = CL2 = 100pF,
(Figures 3 and 7)
●
30
90
200
ns
●
30
90
200
ns
tPHL
3
tSKD
⏐tPLH – tPHL⏐ Differential Receiver Skew
●
13
tZL
Receiver Enable to Output Low
CRL = 15pF (Figures 2 and 8) S1 Closed
●
20
50
ns
tZH
Receiver Enable to Output High
CRL = 15pF (Figures 2 and 8) S2 Closed
●
20
50
ns
tLZ
Receiver Disable from Low
CRL = 15pF (Figures 2 and 8) S1 Closed
●
20
50
ns
tHZ
Receiver Disable from High
CRL = 15pF (Figures 2 and 8) S2 Closed
●
20
50
ns
Note 1: Absolute maximum ratings are those beyond which the safety of
the device cannot be guaranteed.
Note 2: All currents into device pins are positive; all currents out ot device
pins are negative. All voltages are referenced to device ground unless
otherwise specified.
ns
Note 3: All typicals are given for VCC = 5V and TA = 25°C.
Note 4: The LTC485 is guaranteed by design to be functional over a supply
voltage range of 5V ±10%. Data sheet parameters are guaranteed over the
tested supply voltage range of 5V ±5%.
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TYPICAL PERFOR A CE CHARACTERISTICS
Receiver Output Low Voltage
vs Output Current
Receiver Output High Voltage
vs Output Current
36
–18
TA = 25°C
4.8
TA = 25°C
–16
OUTPUT CURRENT (mA)
28
24
20
16
12
8
4
0
4.6
–14
–12
–10
–8
–6
0.5
1.0
1.5
OUTPUT VOLTAGE (V)
2.0
LTC485 • TPC01
4.2
4.0
3.8
3.6
–4
3.4
–2
3.2
0
0
I = 8mA
4.4
OUTPUT VOLTAGE (V)
32
OUTPUT CURRENT (mA)
Receiver Output High Voltage
vs Temperature
5
4
3
OUTPUT VOLTAGE (V)
2
LTC485 • TPC02
3.0
–50
–25
25
50
0
75
TEMPERATURE (°C)
100
125
LTC485 • TPC03
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LTC485
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TYPICAL PERFOR A CE CHARACTERISTICS
Receiver Output Low Voltage
vs Temperature
Driver Differential Output Voltage
vs Output Current
0.9
TA = 25°C
OUTPUT CURRENT (mA)
0.6
0.5
0.4
0.3
0.2
0.1
56
48
40
32
24
16
2.1
2.0
1.9
1.8
1.7
1.6
1.5
–50
0
25
50
0
75
TEMPERATURE (°C)
–25
100
125
1
0
4
3
2
OUTPUT VOLTAGE (V)
LTC485 • TPC03
40
30
20
10
–84
–72
–60
–48
–36
–24
3
2
OUTPUT VOLTAGE (V)
4
1.61
1.60
1.59
1.58
1.57
1.55
–50
0
1
0
1.62
1.56
–12
0
1.63
INPUT THRESHOLD VOLTAGE (V)
OUTPUT CURRENT (mA)
50
1
0
4
3
2
OUTPUT VOLTAGE (V)
LTC485 • TPC07
7.0
4.8
580
6.5
4.2
520
6.0
3.6
3.0
2.4
1.8
4.0
1.2
3.5
0.6
3.0
–50
–25
25
50
0
75
TEMPERATURE (°C)
100
125
LTC485 • TPC10
SUPPLY CURRENT (µA)
640
TIME (ns)
5.4
4.5
0
–50
100
125
Supply Current vs Temperature
7.5
5.0
25
50
0
75
TEMPERATURE (°C)
LTC485 • TPC09
Driver Skew vs Temperature
5.5
–25
LTC485 • TPC08
Receiver ⏐tPLH – tPHL⏐
vs Temperature
125
1.64
TA = 25°C
–96
60
100
TTL Input Threshold
vs Temperature
–108
TA = 25°C
70
25
50
0
75
TEMPERATURE (°C)
LTC485 • TPC06
Driver Output High Voltage
vs Output Current
90
80
–25
LTC485 • TPC05
Driver Output Low Voltage
vs Output Current
OUTPUT CURRENT (mA)
2.2
8
0
–50
RI = 54Ω
2.3
DIFFERENTIAL VOLTAGE (V)
64
0.7
OUTPUT VOLTAGE (V)
2.4
72
I = 8mA
0.8
TIME (ns)
Driver Differential Output Voltage
vs Temperature
DRIVER ENABLED
460
400
340
DRIVER DISABLED
280
220
160
–25
25
50
0
75
TEMPERATURE (°C)
100
125
LTC485 • TPC11
100
–50
–25
25
50
0
75
TEMPERATURE (°C)
100
125
LTC485 • TPC12
sn485 LTC485ffs
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LTC485
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PI FU CTIO S
RO (Pin 1): Receiver Output. If the receiver output is
enabled(RE low), then if A > B by 200mV, RO will be high.
If A < B by 200mV, then RO will be low.
RE (Pin 2): Receiver Output Enable. A low enables the
receiver output, RO. A high input forces the receiver
output into a high impedance state.
DE (Pin 3): Driver Outputs Enable. A high on DE enables
the driver output. A and B, and the chip will function as a
line driver. A low input will force the driver outputs into a
high impedance state and the chip will function as a line
receiver.
DI (Pin 4): Driver Input. If the driver outputs are enabled
(DE high), then a low on DI forces the outputs A low and
B high. A high on DI with the driver outputs enabled will
force A high and B low.
GND (Pin 5): Ground Connection.
A (Pin 6): Driver Output/Receiver Input.
B (Pin 7): Driver Output/Receiver Input.
VCC (Pin 8): Positive Supply; 4.75 < VCC < 5.25.
TEST CIRCUITS
A
1k
RECEIVER
OUTPUT
VOD
R
S1
TEST POINT
R
VCC
CRL
15pF
VOC
1k
S2
LTC485 • F02
B
LTC485 • F01
Figure 1. Driver DC Test Load
Figure 2. Receiver Timing Test Load
3V
DE
A
DI
CL1
RDIFF
S1
A
RO
B
B
CL2
VCC
500Ω
OUTPUT
UNDER TEST
S2
RE
CL
15pF
LTC485 • F02
LTC485 • F03
Figure 3. Driver/Receiver Timing Test Circuit
Figure 4. Driver Timing Test Load #2
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SWITCHI G TI E WAVEFOR S
3V
f = 1MHz, t r ≤ 10ns, t f ≤ 10ns
1.5V
DI
1.5V
0V
t PLH
1/2 VO
t PLH
B
VO
A
tSKEW
1/2 VO
VO
0V
–VO
80%
10%
t SKEW
90%
VDIFF = V(A) – V(B)
tr
20%
tf
LTC485 • F05
Figure 5. Driver Propagation Delays
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SWITCHI G TI E WAVEFOR S
3V
f = 1MHz, t r ≤ 10ns, t f ≤ 10ns
1.5V
DI
1.5V
0V
t ZL
5V
t LZ
A, B
2.3V
OUTPUT NORMALLY LOW
0.5V
2.3V
OUTPUT NORMALLY HIGH
0.5V
VOL
VOH
A, B
0V
t HZ
t ZH
LTC485 • F06
Figure 6. Driver Enable and Disable Times
VOH
1.5V
R
f = 1MHz, t r ≤ 10ns, t f ≤ 10ns
t PHL
VOD2
A, B
–VOD2
1.5V
OUTPUT
VOL
0V
t PLH
INPUT
LTC485 • F07
Figure 7. Receiver Propagation Delays
3V
1.5V
RE
f = 1MHz, t r ≤ 10ns, t f ≤ 10ns
1.5V
0V
t ZL
5V
t LZ
R
R
1.5V
OUTPUT NORMALLY LOW
0.5V
1.5V
OUTPUT NORMALLY HIGH
0.5V
0V
t HZ
t ZH
LTC485 • F08
Figure 8. Receiver Enable and Disable Times
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FU CTIO TABLES
LTC485 Transmitting
LTC485 Receiving
INPUTS
OUTPUTS
INPUTS
OUTPUTS
RE
DE
DI
LINE
CONDITION
X
1
1
No Fault
0
1
0
0
≥ 0.2V
1
X
1
0
No Fault
1
0
0
0
≤ – 0.2V
0
X
0
X
X
Z
Z
0
0
Inputs Open
1
X
1
X
Fault
Z
Z
1
0
X
Z
B
A
RE
DE
A–B
R
sn485 LTC485ffs
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LTC485
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APPLICATIO S I FOR ATIO
Basic Theory of Operation
Previous RS485 transceivers have been designed using
bipolar technology because the common-mode range of
the device must extend beyond the supplies and the device
must be immune to ESD damage and latchup. Unfortunately, the bipolar devices draw a large amount of supply
current, which is unacceptable for the numerous applications that require low power consumption. The LTC485 is
the first CMOS RS485/RS422 transceiver which features
ultra-low power consumption without sacrificing ESD and
latchup immunity.
The LTC485 uses a proprietary driver output stage, which
allows a common-mode range that extends beyond the
power supplies while virtually eliminating latchup and
providing excellent ESD protection. Figure 9 shows the
LTC485 output stage while Figure 10 shows a conventional CMOS output stage.
When the conventional CMOS output stage of Figure 10
enters a high impedance state, both the P-channel (P1)
and the N-channel (N1) are turned off. If the output is then
driven above VCC or below ground, the P + /N-well diode
(D1) or the N + /P-substrate diode (D2) respectively will
turn on and clamp the output to the supply. Thus, the
output stage is no longer in a high impedance state and is
not able to meet the RS485 common-mode range requirement. In addition, the large amount of current flowing
through either diode will induce the well known CMOS
latchup condition, which could destroy the device.
The LTC485 output stage of Figure 9 eliminates these
problems by adding two Schottky diodes, SD3 and SD4.
The Schottky diodes are fabricated by a proprietary modification to the standard N-well CMOS process. When the
output stage is operating normally, the Schottky diodes
are forward biased and have a small voltage drop across
them. When the output is in the high impedance state and
is driven above VCC or below ground, the parasitic diodes
D1 or D2 still turn on, but SD3 or SD4 will reverse bias and
prevent current from flowing into the N-well or the substrate. Thus, the high impedance state is maintained even
with the output voltage beyond the supplies. With no
minority carrier current flowing into the N-well or substrate, latchup is virtually eliminated under power-up or
power-down conditions.
VCC
VCC
SD3
P1
P1
D1
D1
OUTPUT
LOGIC
SD4
N1
D2
LTC485 • F09
Figure 9. LTC485 Output Stage
OUTPUT
LOGIC
N1
D2
LTC485 • F10
Figure 10. Conventional CMOS Output Stage
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LTC485
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APPLICATIO S I FOR ATIO
The LTC485 output stage will maintain a high impedance
state until the breakdown of the N-channel or P-channel is
reached when going positive or negative respectively. The
output will be clamped to either VCC or ground by a Zener
voltage plus a Schottky diode drop, but this voltage is way
beyond the RS485 operating range. This clamp protects
the MOS gates from ESD voltages well over 2000V.
Because the ESD injected current in the N-well or substrate
consists of majority carriers, latchup is prevented by
careful layout techniques.
Propagation Delay
Many digital encoding schemes are dependent upon the
difference in the propagation delay times of the driver and
the receiver. Using the test circuit of Figure 13, Figures 11
and 12 show the typical LTC485 receiver propagation
delay.
The receiver delay times are:
⏐tPLH – tPHL⏐ = 9ns Typ, VCC = 5V
The driver skew times are:
Skew = 5ns Typ, VCC = 5V
10ns Max, VCC = 5V, TA = – 40°C to 85°C
A
A
DRIVER
OUTPUTS
DRIVER
OUTPUTS
B
B
RECEIVER
OUTPUT
RECEIVER
OUTPUT
RO
RO
LTC485 • F11
LTC485 • F12
Figure 11. Receiver tPHL
Figure 12. Receiver tPLH
100pF
TTL IN
t r, t f < 6ns
D
BR
R
R
100Ω
RECEIVER
OUT
LTC485 • F13
100pF
Figure 13. Receiver Propagation Delay Test Circuit
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LTC485
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APPLICATIO S I FOR ATIO
LTC485 Line Length vs Data Rate
The maximum line length allowable for the RS422/RS485
standard is 4000 feet.
Figures 17 and 18 show that the LTC485 is able to
comfortably drive 4000 feet of wire at 110kHz.
RO
100Ω
C
A
LTC485
D
B
TTL
IN
NOISE
GENERATOR
LTC485
TTL
OUT
COMMON MODE
VOLTAGE (A + B)/2
4000 FT 26AWG
TWISTED PAIR
DI
LTC485 • F17
Figure 14. Line Length Test Circuit
Figure 17. System Common Mode Voltage at 110kHz
Using the test circuit in Figure 14, Figures 15 and 16 show
that with ~ 20VP-P common mode noise injected on the
line, The LTC485 is able to reconstruct the data stream at
the end of 4000 feet of twisted pair wire.
RO
COMMON MODE
VOLTAGE (A – B)
RO
DI
COMMON MODE
VOLTAGE (A + B)/2
LTC485 • F18
Figure 18. System Differential Voltage at 110kHz
DI
LTC485 • F15
When specifying line length vs maximum data rate the
curve in Figure 19 should be used:
Figure 15. System Common Mode Voltage at 19.2kHz
CABLE LENGTH (FT)
10k
RO
DIFFERENTIAL
VOLTAGE A – B
DI
1k
100
10
10k
LTC485 • F16
Figure 16. System Differential Voltage at 19.2kHz
100k
1M 2.5M
MAXIMUM DATA RATE
10M
LTC485 • F19
Figure 19. Cable Length vs Maximum Data Rate
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LTC485
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TYPICAL APPLICATIO S
Typical RS485 Network
Rt
Rt
LTC485 • TA03
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PACKAGE DESCRIPTIO
J8 Package
8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
CORNER LEADS OPTION
(4 PLCS)
0.023 – 0.045
(0.584 – 1.143)
HALF LEAD
OPTION
0.045 – 0.068
(1.143 – 1.727)
FULL LEAD
OPTION
0.005
(0.127)
MIN
0.405
(10.287)
MAX
8
7
6
5
0.025
(0.635)
RAD TYP
0.220 – 0.310
(5.588 – 7.874)
1
0.300 BSC
(0.762 BSC)
2
3
4
0.200
(5.080)
MAX
0.015 – 0.060
(0.381 – 1.524)
0.008 – 0.018
(0.203 – 0.457)
0° – 15°
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
0.045 – 0.065
(1.143 – 1.651)
0.014 – 0.026
(0.360 – 0.660)
0.100
(2.54)
BSC
0.125
3.175
MIN
J8 1298
OBSOLETE PACKAGE
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PACKAGE DESCRIPTIO
N8 Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
0.400*
(10.160)
MAX
8
7
6
5
1
2
3
4
0.255 ± 0.015*
(6.477 ± 0.381)
0.300 – 0.325
(7.620 – 8.255)
0.065
(1.651)
TYP
0.009 – 0.015
(0.229 – 0.381)
(
+0.035
0.325 –0.015
8.255
+0.889
–0.381
0.130 ± 0.005
(3.302 ± 0.127)
0.045 – 0.065
(1.143 – 1.651)
)
0.125
(3.175) 0.020
MIN (0.508)
MIN
0.018 ± 0.003
0.100
(2.54)
BSC
(0.457 ± 0.076)
N8 1098
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
8
7
6
5
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
SO8 1298
1
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
0.053 – 0.069
(1.346 – 1.752)
0°– 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.014 – 0.019
(0.355 – 0.483)
TYP
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
2
3
4
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
BSC
sn 485LTC485ffs
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
11
LTC485
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC486/LTC487
Low Power Quad RS485 Drivers
110µA Supply Current
LTC488/LTC489
Low Power Quad RS485 Receivers
7mA Supply Current
LTC490/LTC491
Low Power Full-Duplex RS485 Transceivers
300µA Supply Current
LTC1480
3.3V Supply RS485 Transceiver
Lower Supply Voltage
LTC1481
Low Power RS485 Transceiver with Shutdown
Lowest Power
LTC1482
RS485 Transceiver with Carrier Detect
±15kV ESD, Fail-Safe
LTC1483
Low Power, Low EMI RS485 Transceiver
Slew Rate Limited Driver Outputs, Lowest Power
LTC1484
RS485 Transceiver with Fail-Safe
±15kV ESD, MSOP Package
LTC1485
10Mbps RS485 Transceiver
High Speed
LTC1518/LTC1519
52Mbps Quad RS485 Receivers
Higher Speed, LTC488/LTC489 Pin-Compatible
LTC1520
LVDS-Compatible Quad Receiver
100mV Threshold, Low Channel-to-Channel Skew
LTC1535
2500V Isolated RS485 Transceiver
Full-Duplex, Self-Powered Using External Transformer
LTC1685
52Mbps RS485 Transceiver
Industry-Standard Pinout, 500ps Propagation Delay Skew
LTC1686/LTC1687
52Mbps Full-Duplex RS485 Transceiver
LTC490/LTC491 Pin Compatible
LTC1688/LTC1689
100Mbps Quad RS485 Drivers
Highest Speed, LTC486/LTC487 Pin Compatible
LTC1690
Full-Duplex RS485 Transceiver with Fail-Safe
±15kV ESD, LTC490 Pin Compatible
LT1785/LTC1785A
±60V Protected RS485 Transceivers
±15kV ESD, Fail-Safe (LT1785A)
LT1791/LTC1791A
±60V Protected Full-Duplex RS485 Transceivers
±15kV ESD, Fail-Safe (LT1791A)
sn485 LTC485ffs
12
Linear Technology Corporation
LT/LCG 1101 1.5K REV F • PRINTED IN THE USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 1994