LTC485IS8#PBF [Linear]
LTC485 - Low Power RS485 Interface Transceiver; Package: SO; Pins: 8; Temperature Range: -40°C to 85°C;型号: | LTC485IS8#PBF |
厂家: | Linear |
描述: | LTC485 - Low Power RS485 Interface Transceiver; Package: SO; Pins: 8; Temperature Range: -40°C to 85°C 驱动 光电二极管 接口集成电路 驱动器 |
文件: | 总14页 (文件大小:1016K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
LTC485
Low Power RS485
Interface Transceiver
FEATURES
DESCRIPTION
The LTC®485 is a low power differential bus/line trans-
ceiverdesignedformultipointdatatransmissionstandard
RS485 applications with extended common mode range
(12V to –7V). It also meets the requirements of RS422.
n
Low Power: I = 300μA Typ
CC
n
Designed for RS485 Interface Applications
n
Single 5V Supply
n
–7V to 12V Bus Common Mode Range Permits
7V Ground Difference Between Devices on the Bus
The CMOS design offers significant power savings over
its bipolar counterpart without sacrificing ruggedness
against overload or ESD damage.
n
Thermal Shutdown Protection
n
Power-Up/Down Glitch-Free Driver Outputs
Permit Live Insertion or Removal of Transceiver
n
The driver and receiver feature three-state outputs, with
the driver outputs maintaining high impedance over the
entire common mode range. Excessive power dissipa-
tion caused by bus contention or faults is prevented by a
thermal shutdown circuit which forces the driver outputs
into a high impedance state.
Driver Maintains High Impedance in Three-State
or with the Power Off
n
Combined Impedance of a Driver Output and
Receiver Allows Up to 32 Transceivers on the Bus
n
70mV Typical Input Hysteresis
n
30ns Typical Driver Propagation Delays
with 5ns Skew for Up to 2.5MB Operation
The receiver has a fail-safe feature which guarantees a
high output state when the inputs are left open.
n
Pin Compatible with 60V Protected LTC2862
The LTC485 is fully specified over the commercial and
extended industrial temperature range.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
APPLICATIONS
n
Low Power RS485/RS422 Transceiver
n
Level Translator
TYPICAL APPLICATION
Driver Outputs
RO1
RE1
DE1
DI1
V
CC1
R
A
Rt
Rt
D
GND1
RO2
RE2
DE2
DI2
V
CC2
R
B
D
GND2
485 TA01a
485 TA01b
485fm
1
For more information www.linear.com/LTC485
LTC485
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
Supply Voltage..........................................................12V
RO
RE
DE
DI
1
2
3
4
V
B
A
8
7
6
5
Control Input Voltages .................... –0.5V to V + 0.5V
CC
CC
R
Driver Input Voltage........................ –0.5V to V + 0.5V
CC
Driver Output Voltage.............................................. 14V
D
GND
Receiver Input Voltage............................................ 14V
Receiver Output Voltages............... –0.5V to V + 0.5V
CC
N8 PACKAGE
S8 PACKAGE
8-LEAD PLASTIC DIP 8-LEAD PLASTIC SOIC
Operating Temperature Range
J8 PACKAGE
LTC485I ........................................ –40°C ≤ T ≤ 85°C
OBS8O-LLEAEDTCEERAPMIAC DCIPKAGE
A
LTC485C............................................0°C ≤ T ≤ 70°C
A
LTC485M (OBSOLETE)................–55°C ≤ T ≤ 125°C
T
= 125°C, θ = 100°C/W (N)
JA
A
JMAX
T
= 150°C, θ = 150°C/W (S)
JMAX
JA
Lead Temperature (Soldering, 10 sec)...................300°C
T
= 155°C, θ = 100°C/W (J)
JA
JMAX
Storage Temperature Range .................. –65°C to 150°C
http://www.linear.com/product/LTC485#orderinfo
ORDER INFORMATION
LEAD FREE FINISH
LTC485CN8#PBF
LTC485CS8#PBF
LTC485IN8#PBF
LTC485IS8#PBF
LEAD BASED FINISH
LTC485CN8
TAPE AND REEL
NA
PART MARKING*
LTC485CN8
485
PACKAGE DESCRIPTION
8-Lead Plastic DIP
8-Lead Plastic SOIC
8-Lead Plastic DIP
8-Lead Plastic SOIC
PACKAGE DESCRIPTION
8-Lead Plastic DIP
8-Lead Plastic SOIC
8-Lead Plastic DIP
8-Lead Plastic SOIC
TEMPERATURE RANGE
0°C to 70°C
LTC485CS8#TRPBF
NA
0°C to 70°C
LTC485IN8
485I
–40°C to 85°C
–40°C to 85°C
TEMPERATURE RANGE
0°C to 70°C
LTC485IS8#TRPBF
TAPE AND REEL
NA
PART MARKING*
LTC485CN8
485
LTC485CS8
LTC485CS8#TR
NA
0°C to 70°C
LTC485IN8
LTC485IN8
485I
–40°C to 85°C
–40°C to 85°C
LTC485IS8
LTC485IS8#TR
OBSOLETE PACKAGE
LTC485MJ8
NA
LTC485MJ8
8-Lead Ceramic DIP
–55°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
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/. Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
ELECTRICAL CHARACTERISTICS The l 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
TYP
MAX
UNITS
l
V
V
Differential Driver Output Voltage (Unloaded)
Differential Driver Output Voltage (with Load)
I = 0
5
V
OD1
OD2
O
l
l
R = 50Ω (RS422)
R = 27Ω (RS485), Figure 1
2
1.5
V
V
5
l
ΔV
Change in Magnitude of Driver Differential
Output Voltage for Complementary States
R = 27Ω or R = 50Ω, Figure 1
0.2
V
OD
l
l
V
Driver Common Mode Output Voltage
R = 27Ω or R = 50Ω, Figure 1
R = 27Ω or R = 50Ω, Figure 1
3
V
V
OC
Δ|V
|
Change in Magnitude of Driver Common Mode
Output Voltage for Complementary States
0.2
OC
485fm
2
For more information www.linear.com/LTC485
LTC485
ELECTRICAL CHARACTERISTICS The l 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
DE, DI, RE
DE, DI, RE
DE, DI, RE
MIN
TYP
MAX
UNITS
l
l
l
V
V
Input High Voltage
Input Low Voltage
Input Current
2
V
V
IH
IL
0.8
2
I
I
μA
IN1
IN2
l
l
Input Current (A, B)
DE = 0, V = 0V or 5.25V
V
IN
V
IN
= 12V
= –7V
1
–0.8
mA
mA
CC
C-, I-Grade
l
l
M-Grade
V
IN
V
IN
= 12V
= –7V
2
–1.6
mA
mA
l
l
l
l
l
V
Differential Input Threshold Voltage for Receiver –7V ≤ V ≤ 12V
–0.2
3.5
0.2
V
mV
V
TH
CM
ΔV
Receiver Input Hysteresis
Receiver Output High Voltage
Receiver Output Low Voltage
V
= 0V
CM
70
TH
V
V
I = –4mA, V = 200mV
O ID
OH
I = 4mA, V = –200mV
O
0.4
1
V
OL
ID
I
Three-State (High Impedance) Output Current
at Receiver
V
= Max, 0.4V ≤ V ≤ 2.4V
μA
OZR
CC
O
l
l
R
Receiver Input Resistance
–7V ≤ V ≤ 12V (C-, I-Grade)
12
6
kΩ
kΩ
IN
CM
(M-Grade)
SWITCHING CHARACTERISTICS The l 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
TYP
MAX
UNITS
l
l
I
CC
Supply Current
No Load, Pins 2, 3, 4 = 0V or 5V Outputs Enabled
Outputs Disabled
500
300
900
500
μA
μA
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
I
I
I
t
t
t
Driver Short-Circuit Current, V
Driver Short-Circuit Current, V
Receiver Short-Circuit Current
Driver Input to Output
= HIGH V = – 7V
35
35
7
100
100
250
250
85
mA
mA
mA
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
OSD1
OSD2
OSR
OUT
O
= LOW V = 10V
OUT
O
0V ≤ V ≤ V
O
CC
R
= 54Ω, C = C = 100pF,
10
10
30
30
5
50
PLH
DIFF
L1
L2
(Figures 3 and 5)
Driver Input to Output
50
PHL
Driver Output to Output
10
SKEW
t , t
r
Driver Rise or Fall Time
3
15
40
40
40
40
90
90
13
20
20
20
20
25
f
t
t
t
t
t
t
t
t
t
t
t
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High
Receiver Input to Output
C = 100pF (Figures 4 and 6) S2 Closed
L
70
ZH
ZL
LZ
HZ
C = 100pF (Figures 4 and 6) S1 Closed
L
70
C = 15pF (Figures 4 and 6) S1 Closed
L
70
C = 15pF (Figures 4 and 6) S2 Closed
L
70
R
= 54Ω, CL1 = CL2 = 100pF,
30
30
200
200
PLH
PHL
SKD
ZL
DIFF
(Figures 3 and 7)
|t
– t | Differential Receiver Skew
PHL
PLH
Receiver Enable to Output Low
Receiver Enable to Output High
Receiver Disable from Low
Receiver Disable from High
C
RL
C
RL
C
RL
C
RL
= 15pF (Figures 2 and 8) S1 Closed
= 15pF (Figures 2 and 8) S2 Closed
= 15pF (Figures 2 and 8) S1 Closed
= 15pF (Figures 2 and 8) S2 Closed
50
50
50
50
ZH
LZ
HZ
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 3: All typicals are given for V = 5V and T = 25°C.
CC
A
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%.
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.
485fm
3
For more information www.linear.com/LTC485
LTC485
TYPICAL PERFORMANCE CHARACTERISTICS
Receiver Output Low Voltage
vs Output Current
Receiver Output High Voltage
vs Output Current
Receiver Output High Voltage
vs Temperature
4.8
4.6
4.4
4.2
4.0
3.8
3.6
3.4
3.2
36
32
28
24
20
16
12
8
–18
–16
–14
–12
–10
–8
T
= 25°C
T
= 25°C
A
I = 8mA
A
–6
–4
4
–2
3.0
0
0
–50 –25
0
25
50
125
75 100
0
0.5
2.0
1.0
1.5
5
4
3
2
TEMPERATURE (°C)
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
485 G03
485 G01
485 G02
Receiver Output Low Voltage
vs Temperature
Driver Differential Output Voltage
vs Output Current
Driver Differential Output Voltage
vs Temperature
2.4
2.3
2.2
2.1
2.0
1.9
1.8
1.7
1.6
72
64
56
48
40
32
24
16
8
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
RI = 54Ω
T
= 25°C
I = 8mA
A
1.5
0
0
–50 –25
0
25
50
125
0
1
3
4
75 100
–50 –25
0
25
50
125
2
75 100
TEMPERATURE (°C)
OUTPUT VOLTAGE (V)
TEMPERATURE (°C)
485 G06
485 G05
485 G04
Driver Output Low Voltage
vs Output Current
Driver Output High Voltage
vs Output Current
TTL Input Threshold
vs Temperature
90
80
70
60
50
40
30
20
10
1.64
1.63
1.62
1.61
1.60
1.59
1.58
1.57
1.56
–108
–96
–84
–72
–60
–48
–36
–24
–12
T
= 25°C
T
= 25°C
A
A
0
1.55
0
0
1
3
4
–50 –25
0
25
50
125
2
0
1
3
4
75 100
2
OUTPUT VOLTAGE (V)
TEMPERATURE (°C)
OUTPUT VOLTAGE (V)
485 G07
485 G09
485 G08
485fm
4
For more information www.linear.com/LTC485
LTC485
TYPICAL PERFORMANCE CHARACTERISTICS
Receiver |tPLH – tPHL
|
vs Temperature
Driver Skew vs Temperature
Supply Current vs Temperature
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
5.4
4.8
4.2
3.6
3.0
2.4
1.8
1.2
0.6
640
580
520
460
400
340
280
220
160
DRIVER ENABLED
DRIVER DISABLED
3.0
0
100
–50 –25
0
25
50
125
75 100
–50 –25
0
25
50
125
–50 –25
0
25
50
125
75 100
75 100
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
485 G10
485 G11
485 G12
PIN FUNCTIONS
RO (Pin 1): Receiver Output. If the receiver output is en-
abled (RE low), then if A > B by 200mV, RO will be high.
If A < B by 200mV, then RO will be low.
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.
RE (Pin 2): Receiver Output Enable. A low enables the
receiveroutput,RO.Ahighinputforcesthereceiveroutput
into a high impedance state.
GND (Pin 5): Ground Connection.
A (Pin 6): Driver Output/Receiver Input.
B (Pin 7): Driver Output/Receiver Input.
DE (Pin 3): Driver Output Enable. A high on DE enables
the driver outputs, 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.
V
(Pin 8): Positive Supply; 4.75 < V < 5.25.
CC
CC
485fm
5
For more information www.linear.com/LTC485
LTC485
TEST CIRCUITS
A
S1
S2
TEST POINT
C
1k
R
R
RECEIVER
OUTPUT
V
CC
V
OD
1k
RL
15pF
V
OC
485 F02
B
485 F01
Figure 1. Driver DC Test Load
Figure 2. Receiver Timing Test Load
3V
DE
A
S1
A
B
C
C
L1
L2
RO
V
DI
CC
R
DIFF
500Ω
OUTPUT
UNDER TEST
B
S2
RE
15pF
C
L
485 F04
485 F03
Figure 3. Driver/Receiver Timing Test Circuit
Figure 4. Driver Timing Test Load #2
SWITCHING TIME WAVEFORMS
3V
DI
1.5V
f = 1MHz, t ≤ 10ns, t ≤ 10ns
1.5V
r
f
0V
B
1/2 V
O
t
t
PLH
PLH
V
O
A
t
t
SKEW
1/2 V
SKEW
O
90%
20%
V
O
80%
V
DIFF
= V(A) – V(B)
0V
–V
10%
O
485 F05
t
r
t
f
Figure 5. Driver Propagation Delays
485fm
6
For more information www.linear.com/LTC485
LTC485
SWITCHING TIME WAVEFORMS
3V
1.5V
f = 1MHz, t ≤ 10ns, t ≤ 10ns
1.5V
DI
A, B
A, B
r
f
0V
5V
t
t
LZ
ZL
2.3V
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
0.5V
0.5V
V
OL
OH
0V
V
2.3V
t
HZ
485 F06
t
ZH
Figure 6. Driver Enable and Disable Times
V
OH
1.5V
1.5V
R
OUTPUT
V
OL
f = 1MHz, t ≤ 10ns, t ≤ 10ns
t
t
PLH
r
f
PHL
V
A, B
–V
OD2
OD2
0V
INPUT
485 F07
Figure 7. Receiver Propagation Delays
3V
0V
5V
1.5V
f = 1MHz, t ≤ 10ns, t ≤ 10ns
1.5V
RE
R
r
f
t
ZL
t
LZ
1.5V
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
0.5V
0.5V
R
1.5V
0V
t
485 F08
t
ZH
HZ
Figure 8. Receiver Enable and Disable Times
FUNCTION TABLES
LTC485 Receiving
OUTPUTS
LTC485 Transmitting
INPUTS
OUTPUTS
INPUTS
LINE
RE
0
DE
0
A – B
≥ 0.2V
R
1
0
1
Z
RE
X
DE
1
DI
1
CONDITION
No Fault
No Fault
X
B
0
1
Z
Z
A
1
0
Z
Z
0
0
≤ –0.2V
Inputs Open
X
X
1
0
0
0
X
0
X
X
1
0
X
1
Fault
485fm
7
For more information www.linear.com/LTC485
LTC485
APPLICATIONS INFORMATION
Basic Theory of Operation
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.
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
LTC485isthefirstCMOSRS485/RS422transceiverwhich
features ultralow power consumption without sacrificing
ESD and latchup immunity.
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 modi-
fication 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
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
LTC485outputstagewhileFigure10showsaconventional
CMOS output stage.
is driven above V or below ground, the parasitic diodes
CC
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.
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 V or below ground, the P + /N-well
CC
V
CC
V
CC
SD3
P1
P1
D1
D1
OUTPUT
OUTPUT
D2
LOGIC
LOGIC
SD4
N1
N1
D2
485 F09
485 F10
Figure 9. LTC485 Output Stage
Figure 10. Conventional CMOS Output Stage
485fm
8
For more information www.linear.com/LTC485
LTC485
APPLICATIONS INFORMATION
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.
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
and12showthetypicalLTC485receiverpropagationdelay.
The output will be clamped to either V or ground by a
CC
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
substrateconsistsofmajoritycarriers,latchupisprevented
by careful layout techniques.
The receiver delay times are:
|t
PLH
– t | = 9ns Typ, V = 5V
PHL CC
The driver skew times are:
Skew = 5ns Typ, V = 5V
CC
10ns Max, V = 5V, T = –40°C to 85°C
CC
A
A
A
DRIVER
OUTPUTS
DRIVER
OUTPUTS
B
B
RECEIVER
OUTPUTS
RECEIVER
OUTPUTS
RO
RO
485 F11
485 F12
Figure 11. Receiver tPHL
Figure 12. Receiver tPLH
100pF
BR
RECEIVER
OUT
R
TTL IN
t , t < 6ns
D
R
100Ω
r
f
485 F13
100pF
Figure 13. Receiver Propagation Delay Test Circuit
485fm
9
For more information www.linear.com/LTC485
LTC485
APPLICATIONS INFORMATION
LTC485 Line Length vs Data Rate
Figures 17 and 18 show that the LTC485 is able to com-
fortably drive 4000 feet of wire at 110kHz.
The maximum line length allowable for the RS422/RS485
standard is 4000 feet.
100Ω
RO
C
COMMON MODE
VOLTAGE (A + B)/2
A
TTL
OUT
LTC485
LTC485
D
B
4000 FT 26AWG
TWISTED PAIR
NOISE
GENERATOR
TTL
IN
DI
485 F14
485 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 ~20V common mode noise injected on the
P-P
line, the LTC485 is able to reconstruct the data stream at
the end of 4000 feet of twisted pair wire.
RO
DIFFERENTIAL
VOLTAGE (A – B)
DI
RO
COMMON MODE
VOLTAGE (A + B)/2
485 F18
Figure 18. System Differential Voltage at 110kHz
DI
When specifying line length vs maximum data rate the
curve in Figure 19 should be used.
485 F15
10k
Figure 15. System Common Mode Voltage at 19.2kHz
1k
RO
DIFFERENTIAL
VOLTAGE A – B
100
10
DI
10k
100k
1M 2.5M
10M
MAXIMUM DATA RATE
485 F16
485 F19
Figure 16. System Differential Voltage at 19.2kHz
Figure 19. Cable Length vs Maximum Data Rate
485fm
10
For more information www.linear.com/LTC485
LTC485
TYPICAL APPLICATION
Typical RS485 Network
R
t
R
t
485 TA02
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LTC485#packaging for the most recent package drawings.
J8 Package
8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
.405
(10.287)
MAX
CORNER LEADS OPTION
(4 PLCS)
.005
(0.127)
MIN
6
5
4
8
7
2
.023 – .045
(0.584 – 1.143)
HALF LEAD
OPTION
.025
(0.635)
RAD TYP
.220 – .310
(5.588 – 7.874)
.045 – .068
(1.143 – 1.650)
FULL LEAD
OPTION
1
3
.200
.300 BSC
(5.080)
MAX
(7.62 BSC)
.015 – .060
(0.381 – 1.524)
.008 – .018
(0.203 – 0.457)
0° – 15°
.045 – .065
(1.143 – 1.651)
.125
3.175
MIN
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
.014 – .026
(0.360 – 0.660)
.100
(2.54)
BSC
J8 0801
OBSOLETE PACKAGE
485fm
11
For more information www.linear.com/LTC485
LTC485
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LTC485#packaging for the most recent package drawings.
N Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510 Rev I)
.400*
(10.160)
MAX
.130 ±.005
.300 – .325
.045 – .065
(3.302 ±0.127)
(1.143 – 1.651)
(7.620 – 8.255)
8
1
7
6
5
4
.065
(1.651)
TYP
.255 ±.015*
(6.477 ±0.381)
.008 – .015
(0.203 – 0.381)
.120
.020
(0.508)
MIN
(3.048)
MIN
+.035
–.015
2
3
.325
.018 ±.003
(0.457 ±0.076)
.100
(2.54)
BSC
+0.889
8.255
N8 REV I 0711
(
)
–0.381
NOTE:
INCHES
1. DIMENSIONS ARE
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610 Rev G)
.189 – .197
(4.801 – 5.004)
.045 ±.005
NOTE 3
.050 BSC
7
5
8
6
.245
MIN
.160 ±.005
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
.030 ±.005
TYP
1
3
4
2
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020
(0.254 – 0.508)
× 45°
.053 – .069
(1.346 – 1.752)
.004 – .010
(0.101 – 0.254)
.008 – .010
(0.203 – 0.254)
0°– 8° TYP
.016 – .050
(0.406 – 1.270)
.050
(1.270)
BSC
.014 – .019
(0.355 – 0.483)
TYP
NOTE:
INCHES
1. DIMENSIONS IN
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE
SO8 REV G 0212
485fm
12
For more information www.linear.com/LTC485
LTC485
REVISION HISTORY (Revision history begins at Rev I)
REV
DATE
DESCRIPTION
PAGE NUMBER
I
4/11
Removed lead free version of LTC485MJ8 from Order Information section.
2
1, 3
2
J
01/14 Modified to account for high temperature leakage in M-grade.
02/14 Remove tape and reel option for DIP package in Order Information section.
07/16 Added storage temperature
K
L
2
M
02/17 Obsoleted J8 package
1-14
485fm
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-
13
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
LTC485
RELATED PARTS
PART NUMBER
LTC486/LTC487
LTC488/LTC489
LTC490/LTC491
LTC1480
DESCRIPTION
COMMENTS
Low Power Quad RS485 Drivers
110μA Supply Current
Low Power Quad RS485 Receivers
Low Power Full-Duplex RS485 Transceivers
3.3V Supply RS485 Transceiver
7mA Supply Current
300μA Supply Current
Lower Supply Voltage
LTC1481
Low Power RS485 Transceiver with Shutdown
RS485 Transceiver with Carrier Detect
Low Power, Low EMI RS485 Transceiver
RS485 Transceiver with Fail-Safe
10Mbps RS485 Transceiver
Lowest Power
LTC1482
15kV ESD, Fail-Safe
LTC1483
Slew Rate Limited Driver Outputs, Lowest Power
15kV ESD, MSOP Package
LTC1484
LTC1485
High Speed
LTC1518/LTC1519
LTC1520
52Mbps Quad RS485 Receivers
Higher Speed, LTC488/LTC489 Pin-Compatible
100mV Threshold, Low Channel-to-Channel Skew
Full-Duplex, Self-Powered Using External Transformer
Industry-Standard Pinout, 500ps Propagation Delay Skew
LTC490/LTC491 Pin Compatible
Highest Speed, LTC486/LTC487 Pin Compatible
15kV ESD, LTC490 Pin Compatible
15kV ESD, Fail-Safe (LT1785A)
15kV ESD, Fail-Safe (LT1791A)
15kV ESD, 20Mbps, 900µA Supply Current, Fail-Safe
LVDS-Compatible Quad Receiver
LTC1535
2500V Isolated RS485 Transceiver
52Mbps RS485 Transceiver
LTC1685
LTC1686/LTC1687
LTC1688/LTC1689
LTC1690
52Mbps Full-Duplex RS485 Transceivers
100Mbps Quad RS485 Drivers
Full-Duplex RS485 Transceiver with Fail-Safe
60V Protected RS485 Transceivers
60V Protected Full-Duplex RS485 Transceivers
3.3V Supply RS485 Transceivers
LT1785/LT1785A
LT1791/LT1791A
LTC2850/LTC2851/
LTC2852
LTC2854/LTC2855
3.3V Supply RS485 Transceivers
20Mbps RS485 Transceivers
15kV ESD, 20Mbps, 900µA Supply Current,
Integrated Switchable Termination
LTC2856/LTC2857/
LTC2858
15kV ESD, 900µA Supply Current, Fail-Safe
LTC2859/LTC2861
20Mbps RS485 Transceivers
15kV ESD, 900µA Supply Current, Integrated Switchable Termination
LTC2862/LTC2863/
LTC2864/LTC2865
60V Protected RS485 Transceivers
3V to 5.5V Supply, 15kV ESD, 25V Common Mode Range,
20Mbps or 250kbps
LTM2881
Complete Isolated RS485 Transceiver
2500V
Isolation, Isolated DC Power (5V at Up to 200mA), 3.3V or 5V
RMS
Operation, No External Components Required
485fm
LT 0217 REV M • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
14
(408)432-1900 FAX: (408) 434-0507 www.linear.com/LTC485
●
●
LINEAR TECHNOLOGY CORPORATION 1994
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