LTC2854/LTC2855
7
285455fc
For more information www.linear.com/LTC2854
TYPICAL PERFORMANCE CHARACTERISTICS
Receiver Skew
vs Temperature
Driver Skew vs Temperature
Driver Propagation Delay
vs Temperature
R
TERM
vs Temperature
Driver Output Low/High Voltage
vs Output Current
Driver Differential Output Voltage
vs Temperature
Receiver Propagation Delay
vs Temperature
Supply Current vs Data Rate
T
A
= 25°C, V
CC
= 3.3V, unless otherwise noted.
Receiver Output Voltage vs
Output Current (Source and Sink)
TEMPERATURE (˚C)
–40
RECEIVER SKEW (ns)
1
80
285455 G01
0
2
0 40
–20 100
20 60 120
–1
V
AB
= 1.5V
C
L
= 15pF
TEMPERATURE (˚C)
–40
DRIVER SKEW (ns)
1
80
285455 G02
0
0 40
–20 100
20 60 120
–1
R
DIFF
= 54Ω
C
L
= 100pF
TEMPERATURE (˚C)
–40
PROP DELAY (ns)
12
14
16
80
285455 G03
10
9
0 40
–20 100
20 60 120
6
4
18
R
DIFF
= 54Ω
C
L
= 100pF
TEMPERATURE (˚C)
–40
RESISTANCE (Ω)
120
125
130
80
285455 G04
115
110
0 40
–20 100
20 60 120
105
100
135
OUTPUT CURRENT (mA)
0
OUTPUT VOLTAGE (V)
2
3
60
285455 G05
1
20 40
10
30 50 70
0
V
OH
V
OL
TEMPERATURE (˚C)
–40
OUTPUT VOLTAGE (V)
2
3
80
285455 G06
1
0 40
–20 100
20 60 120
0
R
DIFF
=
R
DIFF
= 100Ω
R
DIFF
= 54Ω
OUTPUT CURRENT (mA)
0
OUTPUT VOLTAGE (V)
2
3
285455 G07
1
2 4
1
3 5 6
0
SOURCE
SINK
TEMPERATURE (˚C)
–40
PROP DELAY (ns)
55
60
65
80
285455 G08
50
45
0 40
–20 100
20 60 120
40
35
70
V
AB
= 1.5V
C
L
= 15pF
DATA RATE (Mbps)
0.1
0
SUPPLY CURRENT (mA)
40
50
60
1 10 100
285455 G09
30
20
10
C
L
= 100pF
R
DIFF
=
R
DIFF
= 100Ω
R
DIFF
= 54Ω
LTC2854/LTC2855
8
285455fc
For more information www.linear.com/LTC2854
PIN FUNCTIONS
RO (Pin 1):
Receiver Output. If the receiver output is en-
abled (RE low) and A > B by 200mV, then RO will be high.
If A< B by 200mV, then RO will be low. If the receiver
inputs are open, shorted, or terminated without a signal,
RO will be high.
RE
(Pin 2): Receiver Enable. A low enables the receiver.
A high input forces the
receiver output into a high imped-
ance state.
DE (Pin 3): Driver Enable. A high on DE enables the driver.
A low input will force the driver outputs into a high imped-
ance. If
RE
is high with DE and TE low, the part will enter
a low power shutdown state.
DI (Pin 4): Driver Input. If the driver outputs are enabled
(DE high), then a low on
DI forces the driver positive out-
put low and negative output high. A high on DI, with the
driver outputs enabled, forces the driver positive output
high and negative output low.
(DD/DE/GN)
TE (Pin 5): Internal Termination Resistance Enable. A high
input will connect a termination resistor (120Ω typical)
between pins A and B.
GND (Pins 6,11/6,13/6): Ground. Pins 11 and 13 are
backside thermal pad, connected to
Ground.
Y (Pins NA/8/12): Positive Driver Output for LTC2855.
Z (Pins NA/9/13): Negative Driver Output for LTC2855.
B (Pins 9/10/14): Negative Receiver Input (and Negative
Driver Output for LTC2854).
A (Pins 8/11/15): Positive Receiver Input (and Positive
Driver Output for LTC2854).
V
CC
(Pins 10/12/16): Positive Supply. V
CC
= 3.0V < V
CC
<
3.6V. Bypass with 0.1µF ceramic capacitor.
LTC2854/LTC2855
9
285455fc
For more information www.linear.com/LTC2854
BLOCK DIAGRAMS
LTC2854
LOGIC INPUTS
DE RE TE MODE A, B RO TERMINATOR
0 0 0 RECEIVE R
IN
DRIVEN OFF
0 0 1 RECEIVE WITH TERM R
TERM
DRIVEN ON
0 1 0 SHUTDOWN R
IN
HIGH-Z OFF
0 1 1 TERM ONLY R
TERM
HIGH-Z ON
1 0 0 TRANSMIT WITH RECEIVE DRIVEN DRIVEN OFF
1 0 1 TRANSMIT WITH RECEIVE
AND TERM
DRIVEN DRIVEN ON
1 1 0 TRANSMIT DRIVEN HIGH-Z OFF
1 1 1 TRANSMIT WITH TERM DRIVEN HIGH-Z ON
LTC2855
LOGIC INPUTS
DE RE TE MODE A, B Y, Z RO TERMINATOR
0 0 0 RECEIVE R
IN
HIGH-Z DRIVEN OFF
0 0 1 RECEIVE WITH TERM R
TERM
HIGH-Z DRIVEN ON
0 1 0 SHUTDOWN R
IN
HIGH-Z HIGH-Z OFF
0 1 1 TERM ONLY R
TERM
HIGH-Z HIGH-Z ON
1 0 0 TRANSMIT WITH RECEIVE R
IN
DRIVEN DRIVEN OFF
1 0 1 TRANSMIT WITH RECEIVE
AND TERM
R
TERM
DRIVEN DRIVEN ON
1 1 0 TRANSMIT R
IN
DRIVEN HIGH-Z OFF
1 1 1 TRANSMIT WITH TERM R
TERM
DRIVEN HIGH-Z ON
LTC2854 LTC2855
DE
RO
DI
A
(15kV)
TE
V
CC
B
(15kV)
Z
(15kV)
Y
(15kV)
SLEEP/SHUTDOWN
LOGIC AND DELAY
RECEIVER
DRIVER
RE
120Ω
R
TERM
120Ω
R
TERM
DE
RO
DI
A
25kV
TE
B
25kV
SLEEP/SHUTDOWN
LOGIC AND DELAY
RECEIVER
DRIVER
RE
285455 BD
V
CC
GND
125k
R
IN
125k
R
IN
125k
R
IN
125k
R
IN
GND
FUNCTION TABLES

LTC2854CDD#PBF

Mfr. #:
Manufacturer:
Analog Devices Inc.
Description:
RS-422/RS-485 Interface IC 3.3V Half-Duplex 20Mbps RS485 Transceiver w/ Integrated Termination
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union