Datasheet
1
LTC1518/LTC1519
52Mbps Precision Delay
RS485 Quad Line Receivers
■
Precision Propagation Delay: 18.5ns ±3.5ns Over
0°C to 70°C Temperature Range
■
High Data Rate:
52Mbps
■
Low t
PLH
/t
PHL
Skew: 500ps Typ
■
Low Channel-to-Channel Skew: 500ps Typ
■
Guaranteed Fail-Safe Operation over the Entire
Common Mode Range
■
–7V to 12V RS485 Input Common Mode Range
■
Input Resistance ≥22k, Even When Unpowered
■
Hot Swap
TM
Capable
■
High Common Mode Rejection to 26MHz
■
Short-Circuit Protection: 10mA Typ Output Current
for an Indefinite Short
■
Three-State Output Capability
■
Will Not Oscillate with Slow Moving Input Signals
■
Single 5V Supply
■
Pin Compatible with LTC488, LTC489
The LTC
®
1518/LTC1519 are high speed, precision delay
differential quad bus/line receivers that can operate at data
rates as high as 52Mbps. They are pin compatible with the
LTC488/LTC489 RS485 line receivers and operate over the
entire –7V to 12V common mode range. A unique architec-
ture provides very stable propagation delays and low skew
over wide input common mode, input overdrive and ambi-
ent temperature ranges. Propagation delay is 18.5ns ±3.5ns
over the commercial temperature range. Typical t
PLH
/t
PHL
and channel-to-channel skew is 500ps.
Each receiver translates differential input levels (V
ID
≥
300mV) into valid CMOS and TTL output levels. Its high
input resistance (≥22k) allows many receivers to be con-
nected to the same driver. The receiver outputs go into a
high impedance state when disabled.
The receivers have a fail-safe feature that guarantees a high
output state when the inputs are shorted or left floating.
Other protection features include thermal shutdown and a
controlled maximum short-circuit current (50mA Max).
Input resistance remains ≥22k when the device is
unpowered or disabled, thus allowing hot swapping with-
out loading the data lines.
The LTC1518/LTC1519 operate from a single 5V supply
and draw 12mA of supply current.
■
High Speed RS485/RS422 Receivers
■
STS-1/OC-1 Data Receivers
■
PECL Line Receivers
■
Level Translators
■
Fast-20/Fast-40 SCSI Receiver
Propagation Delay Guaranteed to Fall
Within Shaded Area (±3.5ns)
52Mbps Data Communication over Twisted Pair
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
FEATURES
DESCRIPTIO
U
APPLICATIO S
U
TYPICAL APPLICATIO
U
1518/19 TA02
V
IN
=
3V/DIV
V
OUT
=
5V/DIV
–5 5 15
TIME (ns)
25 350 1020304045
RECEIVER
INPUT
V
ID
= 1.5V
RECEIVER
OUTPUT
V
DD
= 5V
T
A
= 0°C TO 70°C
100Ω
A 1
4
EN
EN
RO
1518/19 F08
1/4 LTC1518 LTC1685LTC1685
12
3
2 B
7
6
3
2
DE
DI
RO
4
1
100Ω
7
6
3
2
DE
DI
RO
4
1
RE RE