LTC489ISW#PBF [Linear]
LTC489 - Quad RS485 Line Receiver; Package: SO; Pins: 16; Temperature Range: -40°C to 85°C;型号: | LTC489ISW#PBF |
厂家: | Linear |
描述: | LTC489 - Quad RS485 Line Receiver; Package: SO; Pins: 16; Temperature Range: -40°C to 85°C 光电二极管 接口集成电路 |
文件: | 总12页 (文件大小:130K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
LTC488/LTC489
Quad RS485 Line Receiver
FEATURES
DESCRIPTION
The LTC®488 and LTC489 are low power differential bus/
line receivers designed for multipoint data transmission
standard RS485 applications with extended common
mode range (12V to –7V). They also meet the require-
ments of RS422.
n
Low Power: I = 7mA Typ
CC
n
Designed for RS485 or RS422 Applications
n
Single 5V Supply
n
–7V to 12V Bus Common Mode Range Permits 7V
Ground Difference Between Devices on the Bus
n
60mV Typical Input Hysteresis
The CMOS design offers significant power savings over
its bipolar counterpart without sacrificing ruggedness
against overload or ESD damage.
n
Receiver Maintains High Impedance in Three-State or
with the Power Off
28ns Typical Receiver Propagation Delay
n
n
n
Thereceiverfeaturesthree-stateoutputs,withthereceiver
output maintaining high impedance over the entire com-
mon mode range.
Pin Compatible with the SN75173 (LTC488)
Pin Compatible with the SN75175 (LTC489)
The receiver has a fail-safe feature which guarantees a
high output state when the inputs are left open.
APPLICATIONS
n
Low Power RS485/RS422 Receivers
Both AC and DC specifications are guaranteed 4.75V to
5.25V supply voltage range.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
n
Level Translator
TYPICAL APPLICATION
EN
EN
EN
EN
4
2
1
12
DRIVER
1/4 LTC486
RECEIVER
1/4 LTC488
3
120Ω
120Ω
RO
DI
4000 FT 24 GAUGE TWISTED PAIR
EN12
EN12
4
2
1
DRIVER
1/4 LTC487
RECEIVER
1/4 LTC489
3
120Ω
120Ω
RO
DI
4000 FT 24 GAUGE TWISTED PAIR
4889 TA01
4889fb
1
LTC488/LTC489
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Supply Voltage (V ) ................................................12V
Operating Temperature Range
CC
Control Input Currents .......................... –25mA to 25mA
LTC488C/LTC489C ................................... 0°C to 70°C
LTC488I/LTC489I..................................–40°C to 85°C
Storage Temperature Range...................–65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
Control Input Voltages ..................–0.5V to (V + 0.5V)
CC
Receiver Input Voltages .......................................... 14V
Receiver Output Voltages..............–0.5V to (V + 0.5V)
CC
PIN CONFIGURATION
LTC488
LTC488
TOP VIEW
TOP VIEW
B1
A1
1
2
3
4
5
6
7
8
16
V
B1
A1
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC
CC
R
R
R
15 B4
B4
R
R
R
RO1
EN
14
13
12
11
10
9
A4
RO1
EN
A4
RO4
EN
RO4
EN
RO2
A2
RO2
A2
RO3
A3
RO3
A3
R
B2
B2
R
GND
B3
GND
B3
SW PACKAGE
16-LEAD PLASTIC (WIDE) SO
N PACKAGE
16-LEAD PLASTIC DIP
T
= 150°C, θ = 90°C/W
T
= 150°C, θ = 70°C/W
JMAX
JA
JMAX
JA
LTC489
LTC489
TOP VIEW
TOP VIEW
B1
A1
1
16
V
B1
A1
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC
CC
R
R
2
3
4
5
6
7
8
15 B4
B4
R
R
R
RO1
EN12
RO2
A2
14
13
12
11
10
9
A4
RO1
EN12
RO2
A2
A4
RO4
EN34
RO3
A3
RO4
EN34
RO3
A3
R
R
B2
B2
R
GND
B3
GND
B3
SW PACKAGE
16-LEAD PLASTIC (WIDE) SO
= 150°C, θ = 90°C/W
N PACKAGE
16-LEAD PLASTIC DIP
T
T
= 150°C, θ = 70°C/W
JMAX
JA
JMAX
JA
4889fb
2
LTC488/LTC489
ORDER INFORMATION
LEAD FREE FINISH
LTC488CN#PBF
LTC488CSW#PBF
LTC488IN#PBF
TAPE AND REEL
PART MARKING
LTC488CN
PACKAGE DESCRIPTION
16-Lead Plastic DIP
16-Lead Plastic SO
16-Lead Plastic DIP
16-Lead Plastic SO
16-Lead Plastic DIP
16-Lead Plastic SO
16-Lead Plastic DIP
16-Lead Plastic SO
TEMPERATURE RANGE
0°C to 70°C
LTC488CN#TRPBF
LTC488CSW#TRPBF
LTC488IN#TRPBF
LTC488ISW#TRPBF
LTC489CN#TRPBF
LTC489CSW#TRPBF
LTC489IN#TRPBF
LTC489ISW#TRPBF
LTC488CSW
LTC488IN
0°C to 70°C
–40°C to 85°C
–40°C to 85°C
0°C to 70°C
LTC488ISW#PBF
LTC489CN#PBF
LTC489CSW#PBF
LTC489IN#PBF
LTC488ISW
LTC489CN
LTC489CSW
LTC489IN
0°C to 70°C
–40°C to 85°C
–40°C to 85°C
LTC489ISW#PBF
LTC489ISW
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
DC ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 5V (Notes 2, 3), unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
l
l
l
V
V
Input High Voltage
Input Low Voltage
Input Current
EN, EN, EN12, EN34
EN, EN, EN12, EN34
EN, EN, EN12, EN34
2.0
V
V
INH
INL
0.8
2
I
IN1
I
IN2
μA
l
l
Input Current (A, B)
V
V
= 0V or 5.25V, V = 12V
= 0V or 5.25V, V = – 7V
1.0
–0.8
mA
mA
CC
CC
IN
IN
l
V
Differential Input Threshold Voltage for Receiver
Receiver Input Hysteresis
–7V ≤ V ≤ 12V
–0.2
3.5
0.2
V
mV
V
TH
CM
ΔV
V
CM
= 0V
60
7
TH
l
l
l
l
l
l
l
l
V
OH
V
OL
Receiver Output High Voltage
Receiver Output Low Voltage
Three-State Output Current at Receiver
Supply Current
I = –4mA, V = 0.2V
O ID
I = 4mA, V = –0.2V
0.4
1
V
O
ID
I
I
V
CC
= Max 0.4V ≤ V ≤ 2.4V
μA
mA
kΩ
mA
ns
OZR
CC
O
No Load, Digital Pins = GND or V
10
CC
R
Receiver Input Resistance
–7V ≤ V ≤ 12V, V = 0V
12
7
IN
CM
CC
I
t
t
t
Receiver Short-Circuit Current
Receiver Input to Output
0V ≤ V ≤ V
CC
85
55
55
OSR
PLH
PHL
SKD
O
C = 15pF (Figures 1, 3)
L
12
12
28
28
4
Receiver Input to Output
C = 15pF (Figures 1, 3)
L
ns
| t
– t
|
C = 15pF (Figures 1, 3)
L
ns
PLH
PHL
Differential Receiver Skew
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VCC = 5V 5ꢀ (Notes 2, 3), unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
C = 15pF (Figures 2, 4) S1 Closed
MIN
TYP
30
MAX
60
UNITS
ns
l
l
l
l
t
ZL
t
ZH
t
LZ
t
HZ
Receiver Enable to Output Low
Receiver Enable to Output High
Receiver Disable from Low
Receiver Disable from High
L
C = 15pF (Figures 2, 4) S2 Closed
L
30
60
ns
C = 15pF (Figures 2, 4) S1 Closed
L
30
60
ns
C = 15pF (Figures 2, 4) S2 Closed
L
30
60
ns
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.
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: All typicals are given for V = 5V and T = 25°C.
CC
A
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3
LTC488/LTC489
TYPICAL PERFORMANCE CHARACTERISTICS
Receiver Output Low Voltage vs
Temperature at I = 8mA
Receiver Output High Voltage vs
Temperature at I = 8mA
Receiver Output High Voltage vs
Output Current at TA = 25°C
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
4.8
4.6
4.4
–18
–16
–14
–12
–10
4.2
4.0
3.8
3.6
3.4
3.2
3.0
–8
–6
–4
–2
0
0
–50 –25
0
25
50
75 100 125
–50 –25
0
25
50
75 100 125
5
4
3
2
TEMPERATURE (°C)
TEMPERATURE (°C)
OUTPUT VOLTAGE (V)
4889 G01
4889 G02
4889 G03
Receiver Output Low Voltage vs
Output Current at TA = 25°C
TTL Input Threshold vs
Temperature
36
32
28
24
20
1.63
1.61
1.59
1.57
16
12
8
4
1.55
0
–50 –25
0
25
50
75 100 125
0
0.5
1.5
OUTPUT VOLTAGE (V)
1.0
2.0
TEMPERATURE (°C)
8889 G05
4889 G04
Receiver |tPLH – tPHL| vs
Temperature
Supply Current vs Temperature
7.0
6.6
6.2
5.8
5
4
3
2
5.4
1
–50 –25
0
25
50
75 100 125
–50 –25
0
25
50
75 100 125
TEMPERATURE (°C)
TEMPERATURE (°C)
4889 G07
4889 G06
4889fb
4
LTC488/LTC489
PIN FUNCTIONS
B 1 (Pin 1): Receiver 1 Input.
GND (Pin 8): Ground Connection.
A1 (Pin 2): Receiver 1 Input.
B3 (Pin 9): Receiver 3 Input.
RO1 (Pin 3): Receiver 1 Output. If the receiver output
is enabled, then if A > B by 200mV, RO1 will be high. If
A < B by 200mV, then RO1 will be low.
A3 (Pin 10): Receiver 3 Input.
RO3 (Pin 11): Receiver 3 Output. Refer to RO1.
EN (Pin 12) LTC488: Receiver Output Disabled. See Func-
tion Table for details.
EN(Pin4)LTC488:ReceiverOutputEnabled.SeeFunction
Table for details.
EN34 (Pin 12) LTC489: Receiver 3, Receiver 4 output
enabled. See Function Table for details.
EN12 (Pin 4) LTC489: Receiver 1, Receiver 2 Output
Enabled. See Function Table for details.
RO4 (Pin 13): Receiver 4 Output. Refer to RO1.
A4 (Pin 14): Receiver 4 Input.
RO2 (Pin 5): Receiver 2 Output. Refer to RO1.
A2 (Pin 6): Receiver 2 Input.
B4 (Pin 15): Receiver 4 Input.
B2 (Pin 7): Receiver 2 Input.
V
(Pin 16): Positive Supply; 4.75V ≤ V ≤ 5.25V.
CC
CC
FUNCTION TABLES
LTC488
LTC489
DIFFERENTIAL
ENABLES
OUTPUT
DIFFERENTIAL
A – B
ENABLES
OUTPUT
A – B
EN
EN
RO
EN12 or EN34
RO
H
?
V
≥ 0.2V
H
X
X
L
H
H
V
≥ 0.2V
ID
H
H
H
L
ID
–0.2V < V < 0.2V
ID
–0.2V < V < 0.2V
H
X
X
L
?
?
ID
V
X
≤ 0.2V
L
ID
Z
V
X
≤ 0.2V
H
X
X
L
L
L
ID
H: High Level
L: Low Level
X: Irrelevant
?: Indeterminate
Z: High Impedance (Off)
L
H
Z
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5
LTC488/LTC489
TEST CIRCUITS
100pF
A
B
D
RO
DRIVER
RECEIVER
54Ω
C
L
100pF
4889 F01
Figure 1. Receiver Timing Test Circuit
Note: The input pulse is supplied by a generator having the following characteristics:
f = 1MHz, Duty Cycle = 50%, t < 10ns, t ≤ 10ns, Z
= 50Ω
r
f
OUT
S1
S2
1k
RECEIVER
OUTPUT
V
CC
C
1k
L
4889 F02
Figure 2. Receiver Enable and Disable Timing Test Circuit
SWITCHING TIME WAVEFORMS
INPUT
f = 1MHz; t ≤ 10ns; t ≤ 10ns
V
OD2
r
f
INPUT
A, B
0V
t
0V
–V
OD2
t
PHL
PLH
V
OH
RO
1.5V
1.5V
V
OL
4889 F03
Figure 3. Receiver Propagation Delays
3V
f = 1MHz; t ≤ 10ns; t ≤ 10ns
r
f
EN OR
EN12
1.5V
1.5V
0V
5V
t
ZL
t
LZ
RO
RO
1.5V
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
0.5V
V
OL
t
t
ZH
HZ
V
OH
0.5V
1.5V
0V
4889 F04
Figure 4. Receiver Enable and Disable Times
4889fb
6
LTC488/LTC489
APPLICATIONS INFORMATION
Typical Application
Cables and Data Rate
A typical connection of the LTC488/LTC489 is shown in
Figure 5. Two twisted-pair wires connect up to 32 driver/
receiver pairs for half-duplex data transmission. There are
no restrictions on where the chips are connected to the
wires, and it isn’t necessary to have the chips connected
at the ends. However, the wires must be terminated only
at the ends with a resistor equal to their characteristic
impedance, typically 120Ω. The input impedance of a
receiver is typically 20k to GND, or 0.5 unit RS485 load,
so in practice 50 to 60 transceivers can be connected to
the same wires. The optional shields around the twisted-
pair help reduce unwanted noise, and are connected to
GND at one end.
ThetransmissionlineofchoiceforRS485applicationsisa
twisted-pair. There are coaxial cables (twinaxial) made for
this purpose that contain straight-pairs, but these are less
flexible, more bulky, and more costly than twisted-pairs.
Many cable manufacturers offer a broad range of 120Ω
cables designed for RS485 applications.
Losses in a transmission line are a complex combination
of DC conductor loss, AC losses (skin effect), leakage, and
AClossesinthedielectric.Ingoodpolyethylenecablesuch
as the Belden 9841, the conductor losses and dielectric
losses are of the same order of magnitude, leading to
relatively low overall loss (Figure 6).
When using low loss cables, Figure 7 can be used as a
guidelineforchoosingthemaximumlinelengthforagiven
EN
SHIELD
SHIELD
4
2
3
RX
DX
1/4 LTC486
1
3
1/4 LTC488 OR
1/4 LTC489
DX
120Ω
120Ω
RX
1
12
1
2
EN
1/4 LTC488 OR
1/4 LTC489
RX
3
2
12
DX
1/4 LTC486
4
4889 F05
EN
EN
3
1
DX
RX
Figure 5. Typical Connection
10
10k
1k
1
100
10
0.1
2.5M
10k
100k
1M
10M
0.1
1
10
100
DATA RATE (bps)
FREQUENCY (MHz)
4889 F07
4889 F06
Figure 6. Attenuation vs Frequency for Belden 9841
Figure 7. Cable Length vs Data Rate
4889fb
7
LTC488/LTC489
APPLICATIONS INFORMATION
datarate. WithlowerqualityPVCcables, thedielectricloss
factor can be 1000 times worse. PVC twisted-pairs have
terrible losses at high data rates (> 100kbps), and greatly
reduce the maximum cable length. At low data rates how-
ever, they are acceptable and much more economical.
When the reflected signal returns to the driver, the ampli-
tude will be lowered. The width of the pedestal is equal to
twice the electrical length of the cable (about 1.5ns/foot).
If the cable is lightly loaded (470Ω), the signal reflects
in phase and increases the amplitude at the drive output.
An input frequency of 30kHz is adequate for tests out to
4000 ft. of cable.
Cable Termination
The proper termination of the cable is very important. If
the cable is not terminated with its characteristic imped-
ance, distorted waveforms will result. In severe cases,
distorted (false) data and nulls will occur. A quick look
at the output of the driver will tell how well the cable is
terminated. It is best to look at a driver connected to the
end of the cable, since this eliminates the possibility of
getting reflections from two directions. Simply look at the
driver output while transmitting square wave data. If the
cable is terminated properly, the waveform will look like
a square wave (Figure 8).
AC Cable Termination
Cable termination resistors are necessary to prevent un-
wanted reflections, but they consume power. The typical
differential output voltage of the driver is 2V when the
cable is terminated with two 120Ω resistors, causing
33mA of DC current to flow in the cable when no data
is being sent. This DC current is about 60 times greater
than the supply current of the LTC488/LTC489. One way
to eliminate the unwanted current is by AC coupling the
termination resistors as shown in Figure 9.
If the cable is loaded excessively (47Ω), the signal initially
sees the surge impedance of the cable and jumps to an
initial amplitude. The signal travels down the cable and is
reflectedbackoutofphasebecauseofthemistermination.
The coupling capacitor must allow high frequency energy
to flow to the termination, but block DC and low frequen-
cies. The dividing line between high and low frequency
depends on the length of the cable. The coupling capaci-
tor must pass frequencies above the point where the line
represents an electrical one-tenth wavelength. The value
of the coupling capacitor should therefore be set at 16.3pF
perfootofcablelengthfor120Ωcables. Withthecoupling
capacitors in place, power is consumed only on the signal
edges, and not when the driver output is idling at a 1 or 0
state. A 100nF capacitor is adequate for lines up to 4000
feet in length. Be aware that the power savings start to
decrease once the data rate surpasses 1/(120Ω)(C).
PROBE HERE
Rt
DRIVER
RECEIVER
DX
RX
Rt = 120Ω
Rt = 47Ω
120Ω
RECEIVER
RX
C
Rt = 470Ω
488/9 F09
C = LINE LENGTH (FT)(16.3pF)
4889 F08
Figure 9. AC-Coupled Termination
Figure 8. Termination Effects
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8
LTC488/LTC489
APPLICATIONS INFORMATION
Receiver Open-Circuit Fail-Safe
The termination resistors are used to generate a DC bias
which forces the receiver output to a known state, in this
case a logic 0. The first method consumes about 208mW
andthesecondabout8mW.Thelowestpowersolutionisto
use an AC termination with a pullup resistor. Simply swap
the receiver inputs for data protocols ending in logic 1.
Somedataencodingschemesrequirethattheoutputofthe
receiver maintains a known state (usually a logic 1) when
the data is finished transmitting and all drivers on the line
areforcedinthree-state.ThereceiveroftheLTC488/LTC489
has a fail-safe feature which guarantees the output to be
in a logic 1 state when the receiver inputs are left floating
(open-circuit). When the input is terminated with 120Ω
and the receiver output must be forced to a known state,
the circuits of Figure 10 can be used.
Fault Protection
AllofLTC’sRS485productsareprotectedagainstESDtran-
sientsupto2kVusingthehumanbodymodel(100pF,1.5k).
However,someapplicationsneedmoreprotection.Thebest
protectionmethodistoconnectabidirectionalTransZorb®
from each line side pin to ground (Figure 11).
5V
110Ω 130Ω
A TransZorb is a silicon transient voltage suppressor that
has exceptional surge handling capabilities, fast response
time, and low series resistance. They are available from
General instruments, GSI, and come in a variety of break-
down voltages and prices. Be sure to pick a breakdown
voltage higher than the common mode voltage required
for your application (typically 12V). Also, don’t forget to
check how much the added parasitic capacitance will load
down the bus.
RECEIVER
RX
130Ω 110Ω
5V
1.5k
120Ω
1.5k
RECEIVER
RX
Y
5V
DRIVER
120Ω
100k
Z
C
RECEIVER
RX
4889 F11
120Ω
Figure 11. ESD Protection with TransZorbs
4889 F10
Figure 10. Forcing “0” When All Drivers Are Off
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9
LTC488/LTC489
PACKAGE DESCRIPTION
N Package
16-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
.770*
(19.558)
MAX
14
12
10
9
8
15
13
11
16
.255 .015*
(6.477 0.381)
2
1
3
4
6
5
7
.300 – .325
(7.620 – 8.255)
.130 .005
(3.302 0.127)
.045 – .065
(1.143 – 1.651)
.020
(0.508)
MIN
.065
(1.651)
TYP
.008 – .015
(0.203 – 0.381)
+.035
–.015
.325
.120
(3.048)
MIN
.018 .003
(0.457 0.076)
.100
(2.54)
BSC
+0.889
8.255
(
)
–0.381
NOTE:
INCHES
MILLIMETERS
1. DIMENSIONS ARE
N16 1002
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
4889fb
10
LTC488/LTC489
PACKAGE DESCRIPTION
SW Package
16-Lead Plastic Small Outline (Wide .300 Inch)
(Reference LTC DWG # 05-08-1620)
.050 BSC .045 .005
.030 .005
TYP
.398 – .413
(10.109 – 10.490)
NOTE 4
15 14
12
10
9
N
16
N
13
11
.325 .005
.420
MIN
.394 – .419
(10.007 – 10.643)
NOTE 3
N/2
8
1
2
3
N/2
RECOMMENDED SOLDER PAD LAYOUT
2
3
5
7
1
4
6
.291 – .299
(7.391 – 7.595)
NOTE 4
.037 – .045
(0.940 – 1.143)
.093 – .104
(2.362 – 2.642)
.010 – .029
× 45°
(0.254 – 0.737)
.005
(0.127)
RAD MIN
0° – 8° TYP
.050
(1.270)
BSC
.004 – .012
.009 – .013
(0.102 – 0.305)
NOTE 3
(0.229 – 0.330)
.014 – .019
.016 – .050
(0.356 – 0.482)
TYP
(0.406 – 1.270)
NOTE:
1. DIMENSIONS IN
INCHES
(MILLIMETERS)
S16 (WIDE) 0502
2. DRAWING NOT TO SCALE
3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS.
THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS
4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
4889fb
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 representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
11
LTC488/LTC489
TYPICAL APPLICATION
RS232 Receiver
RS232
IN
RECEIVER
1/4 LTC488 OR
1/4 LTC489
RX
5.6k
4889 TA02
RELATED PARTS
PART NUMBER
LTC485
DESCRIPTION
COMMENTS
Low Power RS485 Transceiver
Low Power, Half-Duplex
LTC490
Low Power RS485 Full-Duplex Transceiver
3V, Ultralow Power RS485 Transceiver
3V, Ultralow Power RS485 Transceiver
Ultralow Power RS485 Low EMI Transceiver
Fast RS485 Transceiver
Full-Duplex in SO-8
LTC1480
LTC1481
LTC1483
LTC1485
LTC1487
LTC1685
1μA Shutdown Mode
Lowest Power on 5V Supply
Low EMI/Low Power with Shutdown
10Mbps Operation
Ultralow Power RS485 with Low EMI and High Input Impedance
High Speed RS485 Transceiver
Up to 256 Nodes on a Bus
52Mbps, Pin Compatible with LTC485
52Mbps, Pin Compatible LTC490/LTC491
LTC1686/LTC1687 High Speed RS485 Full-Duplex Transceiver
4889fb
LT 0309 REV B • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
12
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© LINEAR TECHNOLOGY CORPORATION 1992
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
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