High Input Impedance Supports 256 Nodes (C-, I-Grade)
Operation Up to 125°C (H-Grade)
Guaranteed Failsafe Receiver Operation Over the
Entire Common Mode Range
Current Limited Drivers and Thermal Shutdown
Delayed Micropower Shutdown: 5µA Maximum (C-, I-Grade)
Power Up/Down Glitch-Free Driver Outputs
Low Operating Current: 370µA Typical in Receive Mode
Compatible with TIA/EIA-485-A Specifications
Available in 10-Pin 3mm
×
3mm DFN, 12-Pin
4mm × 3mm DFN and 16-Pin SSOP Packages
Low Power RS485/RS422 Transceiver
Level Translator
Backplane Transceiver
APPLICATIONS
n
n
n
PRODUCT SELECTION GUIDE
PART NUMBER
LTC2854
LTC2855
DUPLEX
HALF
FULL
PACKAGE
DFN-10
SSOP-16, DFN-12
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.
TYPICAL APPLICATION
LTC2854
RO
RE
TE
DE
DI
D
LTC2854
120
R
LTC2854
R
RO
RE
TE
DE
D
DI
LTC2854 at 20Mbps into 54
Ω
DI
A
2V/DIV
B
A-B
120
120
285455 TA01
R
D
20ns/DIV
285455 TA01b
RO
RE
TE DE
DI
285455fc
For more information
www.linear.com/LTC2854
1
LTC2854/LTC2855
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Supply Voltage (V
CC
) ................................... –0.3V to 7V
Logic Input Voltages (RE, DE, DI, TE)............ –0.3V to 7V
Interface I/O:
A, B, Y, Z .......................................(V
CC
–15V) to +15V
(A-B) or (B-A) with Terminator Enabled ..................6V
Receiver Output Voltage (RO) ........–0.3V to (V
CC
+0.3V)
Operating Temperature (Note 4)
LTC2854C, LTC2855C .............................. 0°C to 70°C
LTC2854I, LTC2855I ............................–40°C to 85°C
LTC2854H, LTC2855H ....................... –40°C to 125°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
GN Package ...................................................... 300°C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
RO
RE
DE
DI
TE
1
2
3
4
5
11
10 V
CC
9 B
8 A
7 NC
6 GND
RO
RE
DE
DI
TE
GND
DD PACKAGE
10-LEAD (3mm
×
3mm) PLASTIC DFN
1
2
3
4
5
6
13
12 V
CC
11 A
10 B
9
8
7
Z
Y
NC
RO
RE
DE
DI
TE
GND
NC
NC
1
2
3
4
5
6
7
8
TOP VIEW
16 V
CC
15 A
14 B
13 Z
12 Y
11 NC
10 NC
9
NC
EXPOSED PAD (PIN 11) PCB GND CONNECTION
T
JMAX
= 150°C,
θ
JA
= 43°C/W
θ
JC
= 2.96°C/W
DE PACKAGE
12-LEAD (4mm
×
3mm) PLASTIC DFN
EXPOSED PAD (PIN 13) PCB GND CONNECTION
T
JMAX
= 150°C,
θ
JA
= 44°C/W
θ
JC
= 4.3°C/W
GN PACKAGE
16-LEAD (NARROW 0.150) PLASTIC SSOP
T
JMAX
= 150°C,
θ
JA
= 110°C/W
θ
JC
= 40°C/W
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC2854CDD#PBF
LTC2854CDD#TRPBF
LCQG
10-Lead (3mm
×
3mm) Plastic DFN
0°C to 70°C
LTC2854IDD#PBF
LTC2854IDD#TRPBF
LCQG
10-Lead (3mm
×
3mm) Plastic DFN
–40°C to 85°C
LTC2854HDD#PBF
LTC2854HDD#TRPBF
LCQG
10-Lead (3mm
×
3mm) Plastic DFN
–40°C to 125°C
LTC2855CDE#PBF
LTC2855CDE#TRPBF
2855
12-Lead (4mm
×
3mm) Plastic DFN
0°C to 70°C
LTC2855IDE#PBF
LTC2855IDE#TRPBF
2855
12-Lead (4mm
×
3mm) Plastic DFN
–40°C to 85°C
LTC2855HDE#PBF
LTC2855HDE#TRPBF
2855
12-Lead (4mm
×
3mm) Plastic DFN
–40°C to 125°C
LTC2855CGN#PBF
LTC2855CGN#TRPBF
2855
16-Lead (Narrow 0.150) Plastic SSOP
0°C to 70°C
LTC2855IGN#PBF
LTC2855IGN#TRPBF
2855I
16-Lead (Narrow 0.150) Plastic SSOP
–40°C to 85°C
LTC2855HGN#PBF
LTC2855HGN#TRPBF
2855H
16-Lead (Narrow 0.150) Plastic SSOP
–40°C to 125°C
LEAD BASED FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC2854CDD
LTC2854CDD#TR
LCQG
10-Lead (3mm
×
3mm) Plastic DFN
0°C to 70°C
LTC2854IDD
LTC2854IDD#TR
LCQG
10-Lead (3mm
×
3mm) Plastic DFN
–40°C to 85°C
LTC2854HDD
LTC2854HDD#TR
LCQG
10-Lead (3mm
×
3mm) Plastic DFN
–40°C to 125°C
LTC2855CDE#TR
2855
12-Lead (4mm
×
3mm) Plastic DFN
0°C to 70°C
LTC2855CDE
LTC2855IDE
LTC2855IDE#TR
2855
12-Lead (4mm
×
3mm) Plastic DFN
–40°C to 85°C
LTC2855HDE
LTC2855HDE#TR
2855
12-Lead (4mm
×
3mm) Plastic DFN
–40°C to 125°C
LTC2855CGN
LTC2855CGN#TR
2855
16-Lead (Narrow 0.150) Plastic SSOP
0°C to 70°C
LTC2855IGN
LTC2855IGN#TR
2855I
16-Lead (Narrow 0.150) Plastic SSOP
–40°C to 85°C
LTC2855HGN
LTC2855HGN#TR
2855H
16-Lead (Narrow 0.150) Plastic SSOP
–40°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/
2
285455fc
For more information
www.linear.com/LTC2854
LTC2854/LTC2855
ELECTRICAL CHARACTERISTICS
SYMBOL
Driver
|V
OD
|
D|V
OD
|
V
OC
D|V
OC
|
I
OZD
I
OSD
Receiver
I
IN
Receiver Input Current (A, B)
DE = TE = 0V, V
CC
= 0V or 3.3V, V
IN
= 12V
(Figure 3) (C-, I-Grade)
DE = TE = 0V, V
CC
= 0V or 3.3V, V
IN
= –7V,
(Figure 3) (C-, I-Grade)
DE = TE = 0V, V
CC
= 0V or 3.3V, V
IN
= 12V
(Figure 3) (H-Grade)
DE = TE = 0V, V
CC
= 0V or 3.3V, V
IN
= –7V,
(Figure 3) (H-Grade)
R
IN
Receiver Input Resistance
RE
= V
CC
or 0V, DE = TE = 0V,
V
IN
= –7V, –3V, 3V, 7V, 12V (Figure 3)
(C-, I-Grade)
RE
= V
CC
or 0V, DE = TE = 0V,
V
IN
= –7V, –3V, 3V, 7V, 12V (Figure 3)
(H-Grade)
V
TH
DV
TH
V
OH
V
OL
I
OZR
I
OSR
R
TERM
Logic
V
IH
V
IL
I
INL
Supplies
I
CCS
I
CCR
Supply Current in Shutdown Mode
DE = 0V,
RE
= V
CC
, TE = 0V
(C-, I-Grade)
(H-Grade)
DE = 0V,
RE
= 0V, TE = 0V
l
l
l
l
l
l
l
l
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).
PARAMETER
Differential Driver Output Voltage
CONDITIONS
R = ∞, V
CC
= 3V (Figure 1)
R = 27Ω, V
CC
= 3V (Figure 1)
R = 50Ω, V
CC
= 3.13V (Figure 1)
R = 27Ω or R = 50Ω (Figure 1)
l
l
l
l
MIN
TYP
MAX
V
CC
V
CC
V
CC
0.2
UNITS
V
V
V
V
1.5
2
Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States
Driver Common Mode Output Voltage
Change in Magnitude of Driver
Common Mode Output Voltage for
Complementary Output States
Driver Three-State (High Impedance)
Output Current on Y and Z
Maximum Driver Short-Circuit Current
R = 27Ω or R = 50Ω (Figure 1)
R = 27Ω or R = 50Ω (Figure 1)
l
l
3
0.2
V
V
DE = OV, (Y or Z) = –7V, 12V (LTC2855)
H-Grade
–7V ≤ (Y or Z) ≤ 12V (Figure 2)
l
l
l
±10
±50
–250
180
±250
300
125
–100
250
–145
96
125
µA
µA
mA
mA
µA
µA
µA
µA
kΩ
l
48
125
kΩ
Receiver Differential Input Threshold
Voltage
Receiver Input Hysteresis
Receiver Output HIGH Voltage
Receiver Output LOW Voltage
Receiver Three-State (High Impedance)
Output Current on RO
Receiver Short-Circuit Current
Receiver Input Terminating Resistor
–7V ≤ B ≤ 12V
B = 0V
I(RO) = –4mA, A-B = 200mV, V
CC
= 3V
I(RO) = 4mA, A-B = –200mV, V
CC
= 3V
RE
= V
CC
, 0V ≤ RO ≤ V
CC
0V ≤ RO ≤ V
CC
TE = V
CC
, V
AB
= 2V, V
B
= –7V, 0V, 10V
(Figure 8)
V
CC
= 3.6V
V
CC
= 3V
l
±0.2
25
V
mV
V
l
l
l
l
l
2.4
0.4
±1
±85
108
120
156
V
µA
mA
Ω
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Current
l
l
l
2
0.8
0
±10
V
V
µA
0
0
370
5
15
900
µA
µA
µA
285455fc
Supply Current in Receive Mode
For more information
www.linear.com/LTC2854
3
LTC2854/LTC2855
ELECTRICAL CHARACTERISTICS
SYMBOL
I
CCT
I
CCTR
I
CCTERM
I
CCTERMR
I
CCTERMT
I
CCTERMTR
ESD Protection
ESD Protection for RS485/RS422 Pins
A, B on LTC2854, Human Body Model
Y, Z, A, B on LTC2855, Human Body Model
±25
±15
kV
kV
PARAMETER
Supply Current in Transmit Mode
Supply Current with Both Driver and
Receiver Enabled
Supply Current in Termination Mode
Supply Current in Receive and
Termination Mode
Supply Current in Transmit and
Termination Mode
Supply Current with Driver, Receiver
and Termination Enabled
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, T
E
= 0V unless otherwise noted (Note 2).
CONDITIONS
No Load, DE = V
CC
,
RE
= V
CC
, TE = 0V
No Load, DE = V
CC
,
RE
= 0V, TE = 0V
DE = 0V,
RE
= V
CC
, TE = V
CC
DE = 0V,
RE
= 0V, TE = V
CC
DE = V
CC
,
RE
= V
CC
, TE = V
CC
DE = V
CC
,
RE
= 0V, TE = V
CC
l
l
l
l
l
l
MIN
TYP
450
450
110
450
470
470
MAX
1000
1000
180
950
1000
1000
UNITS
µA
µA
µA
µA
µA
µA
SWITCHING CHARACTERISTICS
SYMBOL
Driver
f
MAX
t
PLHD
, t
PHLD
Dt
PD
t
SKEWD
t
RD
, t
FD
t
ZHSD
, t
ZLSD
t
SHDN
Receiver
t
PLHR
, t
PHLR
t
SKEWR
t
RR
, t
FR
t
ZHSR
, t
ZLSR
t
RTEN
, t
RTZ
Receiver Input to Output
Differential Receiver Skew
|t
PLHR
-t
PHLR
|
Receiver Output Rise or Fall Time
Receiver Enable from Shutdown
Termination Enable or Disable Time
Maximum Data Rate
Driver Input to Output
Driver Input to Output Difference
|t
PLHD
-t
PHLD
|
Driver Output Y to Output Z
Driver Rise or Fall Time
Driver Enable from Shutdown
Time to Shutdown
PARAMETER
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, T
E
= 0V unless otherwise noted (Note 2).
CONDITIONS
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
= 0 (Figure 5)
R
L
= 500Ω, C
L
= 50pF,
RE
= V
CC
(Figure 5)
R
L
= 500Ω, C
L
= 50pF
(DE =
↓,
RE
= V
CC
) or (DE = 0,
RE
↑)
(Figure 5)
C
L
= 15pF, V
CM
= 1.5V, |V
AB
| = 1.5V, t
R
and
t
F
< 4ns (Figure 6)
C
L
= 15pF (Figure 6)
C
L
= 15pF (Figure 6)
R
L
= 1k, C
L
=15pF, DE = V
CC
(Figure 7)
R
L
= 1k, C
L
= 15pF, DE = 0V (Figure 7)
V
B
= 0V, V
AB
= 2V,
RE
= V
CC
, DE = 0V
(Figure 8)
l
l
l
l
l
l
l
l
MIN
20
TYP
MAX
UNITS
Mbps
10
1
1
4
50
6
±6
12.5
70
8
100
ns
ns
ns
ns
ns
µs
ns
t
ZLD
, t
ZHD
, t
LZD
, t
HZD
Driver Enable or Disable Time
l
l
l
l
l
l
50
1
3
70
6
12.5
50
8
100
ns
ns
ns
ns
µs
µs
t
ZLR
, t
ZHR
, t
LZR
, t
HZR
Receiver Enable/Disable
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.
285455fc
4
For more information
www.linear.com/LTC2854
LTC2854/LTC2855
TEST CIRCUITS
Y
GND
DI
OR
V
CC
DRIVER
Z
+
V
OD
–
R
Y
GND
OR
DI
V
CC
I
OSD
DRIVER
Z
R
+
V
OC
–
+
–
285455 F01-2
–7V to +12V
Figure 1. Driver DC Characteristics
Figure 2. Driver Output Short-Circuit Current
I
IN
A OR B
RECEIVER
V
IN
+
–
B OR A
285455 F03
V
R
IN
=
IN
I
IN
Figure 3. Receiver Input Current and Input Resistance
Y
DI
C
L
DRIVER
R
DIFF
C
L
Z
285455 F04a
DI
V
CC
0V
t
PLHD
t
SKEWD
t
PHLD
Y, Z
V
O
1/2 V
O
Y-Z
90%
10%
0
t
RD
0
90%
10%
t
FD
285455 F04b
Figure 4. Driver Timing Measurement
Y
V
CC
OR
GND
DI
C
L
DRIVER
DE
R
L
GND
OR
V
CC
DE
V
CC
0V
V
CC
V
OL
V
O
1/2 V
CC
t
ZLD,
t
ZLSD
1/2 V
CC
t
LZD
0.5V
0.5V
t
HZD,
t
SHDN
285455 F05b
Y OR Z
R
L
Z
C
L
V
CC
OR
GND
285455 F05a
Z OR Y
V
OH
0V
t
ZHD,
t
ZHSD
1/2 V
CC
Figure 5. Driver Enable and Disable Timing Measurements
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