LINER LTC1518CS 52mbps precision delay rs485 quad line receiver Datasheet

LTC1518/LTC1519
52Mbps Precision Delay
RS485 Quad Line Receivers
U
FEATURES
■
■
■
■
■
■
■
■
■
■
■
■
■
■
DESCRIPTIO
Precision Propagation Delay: 18.5ns ±3.5ns Over
0°C to 70°C Temperature Range
High Data Rate: 52Mbps
Low tPLH/tPHL 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 SwapTM 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
U
APPLICATIO S
■
■
■
■
■
High Speed RS485/RS422 Receivers
STS-1/OC-1 Data Receivers
PECL Line Receivers
Level Translators
Fast-20/Fast-40 SCSI Receiver
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 architecture provides very stable propagation delays and low skew
over wide input common mode, input overdrive and ambient temperature ranges. Propagation delay is 18.5ns ±3.5ns
over the commercial temperature range. Typical tPLH/tPHL
and channel-to-channel skew is 500ps.
Each receiver translates differential input levels (VID ≥
300mV) into valid CMOS and TTL output levels. Its high
input resistance (≥ 22k) allows many receivers to be connected 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 without loading the data lines.
The LTC1518/LTC1519 operate from a single 5V supply
and draw 12mA of supply current.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Hot Swap is a trademark of Linear Technology Corporation.
U
Propagation Delay Guaranteed to Fall
Within Shaded Area (±3.5ns)
TYPICAL APPLICATIO
TA = 0°C TO 70°C
52Mbps Data Communication over Twisted Pair
RE
2
RO
RE
2
1
1
DI
4
3
DE
LTC1685
6
RO
7
7
100Ω
100Ω
EN
EN
4 A 1
2 B
1/4 LTC1518
12
4
6
RECEIVER
INPUT
VID = 1.5V
VIN =
3V/DIV
DI
RECEIVER
OUTPUT
VDD = 5V
VOUT =
5V/DIV
3
DE
LTC1685
3
RO
1518/19 F08
–5
0
5
10 15 20 25 30 35 40 45
TIME (ns)
1518/19 TA02
1
LTC1518/LTC1519
W W
W
AXI U
U
ABSOLUTE
RATI GS
(Note 1)
Supply Voltage ....................................................... 10V
Digital Input Currents ..................... – 100mA to 100mA
Digital Input Voltages ............................... – 0.5V to 10V
Receiver Input Voltages ........................................ ±14V
Receiver Output Voltages ............. – 0.5V to VDD + 0.5V
Receiver Input Differential ....................................... 10V
Short-Circuit Duration .................................... Indefinite
Operating Temperature Range
LTC1518C/LTC1519C ............................. 0°C to 70°C
LTC1518I/LTC1519I .......................... – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
U
U
W
PACKAGE/ORDER I FOR ATIO
TOP VIEW
B1 1
16 VDD
A1 2
15 B4
OUT 1 3
14 A4
EN 4
OUT 2 5
13 OUT 4
ORDER PART
NUMBER
LTC1518CS
LTC1518IS
12 EN
B1 1
16 VDD
A1 2
15 B4
OUT 1 3
14 A4
EN12 4
13 OUT 4
OUT 2 5
12 EN34
A2 6
11 OUT 3
A2 6
11 OUT 3
B2 7
10 A3
B2 7
10 A3
GND 8
9
ORDER PART
NUMBER
TOP VIEW
9
GND 8
B3
LTC1519CS
LTC1519IS
B3
S PACKAGE
16-LEAD PLASTIC SO
S PACKAGE
16-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 90°C/ W
TJMAX = 150°C, θJA = 90°C/ W
Consult factory for Military grade parts.
DC ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VDD = 5V ±5% (Notes 2, 3) per receiver, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
VCM
Input Common Mode Voltage
A, B Inputs
●
MIN
–7
VIH
Input High Voltage
EN, EN, EN12, EN34
●
2
VIL
Input Low Voltage
EN, EN, EN12, EN34
●
IIN1
Input Current
EN, EN, EN12, EN34
●
–1
IIN2
Input Current (A, B)
VA, VB = 12V
VA, VB = – 7V
●
●
●
MAX
12
V
V
V
1
µA
500
– 500
µA
µA
22
kΩ
Input Resistance
– 7V ≤ VCM ≤ 12V (Figure 5)
CIN
Input Capacitance
(Note 4)
VOC
Open-Circuit Input Voltage
VDD = 5V (Note 4) (Figure 5)
●
3.2
VID(MIN)
Differential Input Threshold Voltage
– 7V ≤ VCM ≤ 12V
●
– 0.3
dVID
Input Hysteresis
VCM = 2.5V
VOH
Output High Voltage
IOUT = – 4mA, VID = 0.3V, VDD = 5V
●
VOL
Output Low Voltage
IOUT = 4mA, VID = – 0.3V, VDD = 5V
●
IOZR
Three-State Output Current
0V < VOUT < 5V
●
IDD
Total Supply Current All 4 Receivers
VID > 0.3V, No Load, Device Enabled ●
IOSR
Short-Circuit Current
VOUT = 0V, VOUT = 5V (Note 7)
3
3.3
pF
3.4
V
0.3
V
25
●
UNITS
0.8
RIN
2
TYP
mV
4.6
V
– 10
12
– 50
0.4
V
10
µA
20
mA
50
mA
LTC1518/LTC1519
DC ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VDD = 5V ±5% (Notes 2, 3) per receiver, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
Max VID for Fail-Safe Detection
–7V ≤ VCM ≤ 12V
25
2
µs
VCM = 2.5V, f = 26MHz (Note 4)
45
dB
Min Time to Detect Fault Condition
CMRR
Common Mode Rejection Ratio
TYP
MAX
UNITS
mV
U
W
SWITCHI G TI E CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VDD = 5V ±5% (Notes 2, 3) VID = 1.5V, VCM = 2.5V, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
tPLH, tPHL
Input-to-Output Propagation Delay
CL = 15pF, 0°C ≤ TA ≤ 70°C (Figure 1)
CL = 15pF, – 40°C ≤ TA ≤ 85°C (Figure 1)
tr, tf
Rise/Fall Times
CL = 15pF
2.5
ns
tSKD
tPLH – tPHL Skew
CL = 15pF, Same Receiver (Note 5)
500
ps
tZL
Enable to Output Low
CL = 15pF, 0°C ≤ TA ≤ 70°C (Figure 2)
CL = 15pF, – 40°C ≤ TA ≤ 85°C (Figure 2)
●
10
15
35
ns
ns
tZH
Enable to Output High
CL = 15pF, 0°C ≤ TA ≤ 70°C (Figure 2)
CL = 15pF, – 40°C ≤ TA ≤ 85°C (Figure 2)
●
10
15
35
ns
ns
tLZ
Disable from Output Low
CL = 15pF, 0°C ≤ TA ≤ 70°C (Figure 2)
CL = 15pF, – 40°C ≤ TA ≤ 85°C (Figure 2)
●
20
25
35
ns
ns
tHZ
Disable from Output High
CL = 15pF, 0°C ≤ TA ≤ 70°C (Figure 2)
CL = 15pF, – 40°C ≤ TA ≤ 85°C (Figure 2)
●
20
25
35
ns
ns
tCH-CH
Channel-to-Channel Skew
CL = 15pF (Figure 3, Note 6)
500
ps
tPKG-PKG
Package-to-Package Skew
CL = 15pF, Same Temperature
(Figure 4, Note 4)
1.5
ns
tr, tf Input
Maximum Input Rise or Fall Time
(Note 4)
●
Minimum Input Pulse Width
0°C ≤ TA ≤ 70°C (Note 4)
– 40°C ≤ TA ≤ 85°C (Note 4)
●
●
Maximum Input Frequency
Square Wave, 0°C ≤ TA ≤ 70°C (Note 4)
Square Wave, – 40°C ≤ TA ≤ 85°C (Note 4)
●
●
26
20
40
30
MHz
MHz
Maximum Data Rate
0°C ≤ TA ≤ 70°C (Note 4)
– 40°C ≤ TA ≤ 85°C (Note 4)
●
●
52
40
80
65
Mbps
Mbps
Load Capacitance
(Note 4)
fIN(MAX)
CL
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: All currents into the device pins are positive; all currents out of the
device pins are negative.
Note 3: All typicals are given for VDD = 5V, TA = 25°C.
Note 4: Guaranteed by design, but not tested.
●
●
MIN
TYP
MAX
15
12
18.5
22
25
12
16
UNITS
ns
ns
2000
ns
19.2
25
ns
ns
500
pF
Note 5: Worst-case tPLH – tPHL skew for a single receiver in a package
over the full operating temperature range.
Note 6: Maximum difference between any two tPLH or tPHL transitions in a
single package over the full operating temperature range.
Note 7: Short-circuit current does not represent output drive capability.
When the output detects a short-circuit condition, output drive current is
significantly reduced until the short is removed.
3
LTC1518/LTC1519
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Propagation Delay (tPLH/tPHL)
vs Temperature
CMRR vs Frequency
45.0
44.5
44.0
43.5
43.0
TA = 25°C
VCM = 2.5V
42.5
1k
20
40
15
10
5
100k
FREQUENCY (Hz)
10M
50
25
0
75
TEMPERATURE (°C)
100
15
100°C
25°C
0°C
–25°C
–50°C
50
20
15
10
20
15
10
5
0
5 15 25
35
55
105
LOAD CAPACITANCE (pF)
205
–6 –4
–2
8
0
4
6
2
COMMON MODE (V)
15189 G05
Propagation Delay
vs Input Differential Voltage
70
TA = 25°C
VCM = 2.5V
60
DATA RATE (Mbps)
20
15
10
TA = 25°C
VCM = 2.5V
50
40
30
20
5
10
2.5
15189 G07
4
0
0.3 0.5
10
12
15189 G06
Maximum Data Rate
vs Input Differential Voltage
25
1.0
1.5
2.0
INPUT DIFFERENTIAL (V)
50
TA = 25°C
VID = 1.5V
15189 G04
0
0.3 0.5
40
25
TA = 25°C
VCM = 2.5V
VID = 1.5V
0
0
40
30
20
DATA RATE (Mbps)
Propagation Delay
vs Common Mode
5
30
20
DATA RATE (Mbps)
10
0
15189 G03
PROPAGATION DELAY (ns)
PROPAGATION DELAY (ns)
25
20
PROPAGATION DELAY (ns)
15
0
125
30
VCM = 2.5V
VID = 1.5V
25 1 RECEIVER
SWITCHING
10
1 RECEIVER
SWITCHING
20
Propagation Delay
vs Load Capacitance
30
0
25
15189 G02
Supply Current
vs Temperature and Data Rate
5
4 RECEIVERS
SWITCHING
30
5
15189 G01
10
35
10
0
–50 –25
42.0
10
TA = 25°C
VCM = 2.5V
VID = 1.5V
45
SUPPLY CURRENT (mA)
45.5
PROPAGATION DELAY (ns)
COMMON MODE REJECTION RATIO (dB)
50
VCM = 2.5V
VID = 1.5V
46.0
SUPPLY CURRENT (mA)
Supply Current vs Data Rate
25
46.5
1.0
1.5
2.0
INPUT DIFFERENTIAL (V)
2.5
15189 G08
LTC1518/LTC1519
U
U
U
PI FU CTIO S
LTC1518
LTC1519
B1 (Pin 1): Receiver 1 Inverting Input.
B1 (Pin 1): Receiver 1 Inverting Input.
A1 (Pin 2): Receiver 1 Noninverting Input.
A1 (Pin 2): Receiver 1 Noninverting Input.
OUT 1 (Pin 3): Receiver 1 Output.
OUT 1 (Pin 3): Receiver 1 Output.
EN (Pin 4): A high enables all outputs; a low on Pin 4 and
a high on Pin 12 will put all outputs into a high impedance
state. Do not float.
EN12 (Pin 4): A high enables receivers 1 and 2; a low will
put the outputs of receivers 1 and 2 into a high impedance
state. Do not float.
OUT 2 (Pin 5): Receiver 2 Output.
OUT 2 (Pin 5): Receiver 2 Output.
A2 (Pin 6): Receiver 2 Noninverting Input.
A2 (Pin 6): Receiver 2 Noninverting Input.
B2 (Pin 7): Receiver 2 Inverting Input.
B2 (Pin 7): Receiver 2 Inverting Input.
GND (Pin 8): Ground Pin. A ground plane is recommended
for all LTC1518 applications.
GND (Pin 8): Ground Pin. A ground plane is recommended
for all LTC1519 applications.
B3 (Pin 9): Receiver 3 Inverting Input.
B3 (Pin 9): Receiver 3 Inverting Input.
A3 (Pin 10): Receiver 3 Noninverting Input.
A3 (Pin 10): Receiver 3 Noninverting Input.
OUT 3 (Pin 11): Receiver 3 Output.
OUT 3 (Pin 11): Receiver 3 Output.
EN (Pin 12): A low enables all outputs; a low on Pin 4 and
a high on Pin 12 will put all outputs into a high impedance
state. Do not float.
EN34 (Pin 12): A high enables receivers 3 and 4; a low will
put the outputs of receivers 3 and 4 into a high impedance
state. Do not float.
OUT 4 (Pin 13): Receiver 4 Output.
OUT 4 (Pin 13): Receiver 4 Output.
A4 (Pin 14): Receiver 4 Noninverting Input.
A4 (Pin 14): Receiver 4 Noninverting Input.
B4 (Pin 15): Receiver 4 Inverting Input.
B4 (Pin 15): Receiver 4 Inverting Input.
VDD (Pin 16): Power Supply Input. This pin should be
decoupled with a 0.1µF ceramic capacitor as close as
possible to the pin. Recommended: VDD = 5V ±5%.
VDD (Pin 16): Power Supply Input. This pin should be
decoupled with a 0.1µF ceramic capacitor as close as
possible to the pin. Recommended: VDD = 5V ±5%.
5
LTC1518/LTC1519
U
W
W
SWITCHI G TI E WAVEFOR S
t r = t f ≤ 3ns for all input and enable signals.
3V
+
INPUT
1.5V
0V
1/4
LTC1518
LTC1519
5V
15pF
t LZ
t ZL
OUTPUT
–
2.5V
1.5V
ENABLE
OUT 1
2.5V
OUTPUT
NORMALLY LOW
2.5V
OUTPUT
NORMALLY HIGH
VOL
1518/19 F01b
VOH
OUT 1
0V
4V
2.5V
INPUT
OUTPUT
t HZ
1V
S1
RECEIVER
OUTPUT
t PHL
VDD/2
1k
Figure 1. Propagation Delay Test Circuit and Waveforms
Figure 2. Receiver Enable and Disable Timing Test Circuit
and Waveforms
4V
1V
B1, B2 = 2.5V
VDD/2
VDD/2
t CH-CH
CH2 OUT
t CH-CH
VDD/2
VDD/2
1518/19 F03
Figure 3. Any Channel to Any Channel Skew, Same Package
INPUT
A1, B1
VID = 1.5V
SAME INPUT FOR BOTH PACKAGES
PACKAGE 1
OUT 1
t PKG-PKG
tPKG-PKG
PACKAGE 2
OUT 1
1518/19 F04
Figure 4. Package-to-Package Propagation Delay Skew
6
S2
1518/19 F02
1518/19 F01
CH1 OUT
1k
VDD
CL
VDD/2
INPUT
A1, A2
0.2V
t ZH
2.5V
t PLH
0.2V
LTC1518/LTC1519
U U
EQUIVALE T I PUT NETWORKS
≥ 22k
≥ 22k
A
3.3V
A
≥ 22k
≥ 22k
B
3.3V
RECEIVER ENABLED, VDD = 5V
B
RECEIVER DISABLED OR VDD = 0V
1518/19 F05
Figure 5. Input Thevenin Equivalent
U
W
U U
APPLICATIO S I FOR ATIO
Theory of Operation
Fail-Safe Features
Unlike typical line receivers whose propagation delay can
vary by as much as 500% from package to package and
show significant temperature drift, the LTC1518/LTC1519
employ a novel architecture that produces a tightly controlled and temperature compensated propagation delay.
The differential timing skew is also minimized between
rising and falling output edges, and the propagation delays
of any two receivers within a package are very tightly
matched.
The LTC1518/LTC1519 have a fail-safe feature that guarantees the output to be in a logic HIGH state when the
inputs are either shorted or left open (note that when
inputs are left open, any external large leakage current
might override the fail-safe). The fail-safe feature detects
shorted inputs over the entire common mode range. When
a fault is detected, the output will typically go high in 2µs.
The precision timing features of the LTC1518/LTC1519
reduce overall system timing constraints by providing a
narrow ±3.5ns window during which valid data appears at
the receiver output. This output timing window applies to
all receivers in all packages over the commercial operating
temperature range, thereby making the LTC1518/LTC1519
well suited for high speed data transmission.
In clocked data systems, the low skew minimizes duty
cycle distortion of the clock signal. The LTC1518/LTC1519
can propagate signals at frequencies of 26MHz (52Mbps)
with less than 5% duty cycle distortion. When a clock
signal is used to retime parallel data, the maximum recommended data transmission rate is 25Mbps to avoid timing
errors due to clock distortion.
Thermal shutdown and short-circuit protection prevent
latchup damage to the LTC1518/LTC1519 during fault
conditions.
When some of the receivers within a package are not
used, the open fail-safe feature will allow the user to let
the receiver inputs float and maintain a high logic state at
the output. Without the open fail-safe feature, any noise
at the input would cause unwanted glitches at the output.
When the inputs are left “open,” one must make sure that
there are no sources of leakage current connected to one
or both of the inputs. This can happen if the device is
being driven single-endedly and both the signal and the
DC bias are disconnected. If the capacitor used to bypass
the DC bias is left connected to the input of the device and
is leaky (>1µA), the output of the device might not be the
desired high logic state. Also keep in mind that the inputs
are high impedance (≥ 22kΩ). When left open, noisy
traces should be kept away from the receiver inputs to
minimize capacitive coupling of undesired signals. Even
with the open fail-safe feature, for maximum noise
immunity, grounding the negative input of unused receivers is recommended.
7
LTC1518/LTC1519
U
W
U U
APPLICATIO S I FOR ATIO
When the inputs are accidentally shorted (by cutting
through a cable, for example), the short-circuit fail-safe
feature will guarantee a high output logic level. Note also
that if the line driver is removed and the termination
resistors are left in place, the receiver will see this as a
“short” and output a logic high.
Both of these fail-safe features will keep the receiver from
outputting false data pulses under fault conditions.
Single-Ended Applications
Over short distances, the LTC1518/LTC1519 can be
configured to receive single-ended data by tying one
input to a fixed bias voltage and connecting the other
input to the driver output. In such applications, standard
high speed CMOS logic may be used as a driver for the
LTC1518/LTC1519. With a 22k minimum input resistance, the receiver trip points may be easily adjusted to
accommodate different driver output swings by changing the resistor divider at the fixed input. Figure 6a shows
a single-ended receiver configuration with the driver and
receiver connected via PC traces. Note that at very high
speeds, transmission line and driver ringing effects must
be considered. Motorola’s MECL System Design Handbook serves as an excellent reference for transmission
line and termination effects. To mitigate transmission
errors and duty cycle distortion due to driver ringing, a
small output filter or a dampening resistor on the driver’s
VDD may be needed as shown in Figure 6b. With an open
circuit voltage of 3.3V at both inputs, the receivers can be
used without an external bias applied to the fixed inputs.
The fixed input should be bypassed with a 0.01µF ceramic capacitor. The positive input should be driven with
a 5V CMOS part in order to minimize the skew caused by
the 3.3V threshold. Figure 6c shows this configuration.
MC74ACT04
(TTL INPUT)
PC TRACE
–
5V
MC74AC04
(CMOS INPUT)
2.2k
0.01µF
1/4
LTC1518
LTC1519
10Ω
MC74AC04
+
0.01µF
10Ω
PC TRACE
2.2k
OR
PC TRACE
10pF
1518/19 F06a
1518/19 F06b
Figure 6b. Techniques to Minimize Driver Ringing
Figure 6a. Single-Ended Receiver
MC74ACT04
(TTL INPUT)
PC TRACE
–
1/4
LTC1518
LTC1519
MC74AC04
(CMOS INPUT)
+
0.01µF
1518/19 F06c
Figure 6c. Self Biased Single Ended Receiver
8
LTC1518/LTC1519
U
W
U U
APPLICATIO S I FOR ATIO
Note that due to the increased skew, this configuration
might not operate at the highest data rates. To transmit
single-ended data over short to medium distances, twisted
pair is recommended with the unused wire grounded at
both ends (Figure 7).
Differential Transmission
Data rates up to 52Mbps can be transmitted over 100 feet
of high quality category 5 twisted pair. Figure 8 shows the
LTC1518 receiving differential data from an LTC1685
transceiver. As in the single-ended configurations, care
must be taken to properly terminate the differential data
lines to avoid unwanted reflections, etc.
5V
100Ω 10-FT TWISTED PAIR
–
100Ω
MC74ACT04
MC74AC04
1/4
LTC1518
LTC1519
+
5V
3.3k
0.01µF
1k
1518/19 F07
Figure 7. Medium Distance Single-Ended Transmission
Using a CMOS Driver
RE
2
RO
RE
2
1
1
7
7
DI
4
3
DE
LTC1685
6
RO
100Ω
100Ω
EN
EN
4 A 1
2 B
1/4 LTC1518
12
4
6
DI
3
DE
LTC1685
3
RO
1518/19 F08
Figure 8. LTC1518 Connected to LTC1685
High Speed RS485 Transceiver
9
LTC1518/LTC1519
U
W
U U
APPLICATIO S I FOR ATIO
Figure 9 shows a trace with 100ft category 5 UTP between
an LTC1685 driver and an LTC1518 receiver. Notice that at
the far end of the cable, the signal to the LTC1518 input has
been reduced. Figure 10 shows a 52Mbps square wave.
Output Short-Circuit Protection
The LTC1518/LTC1519 employ voltage sensing shortcircuit protection at the output terminals. For a given input
differential, this circuitry determines what the correct
2V/DIV
output level should be. For example, if the input differential
is ≥ 300mV, it expects the output to be a logic high. If the
output is subsequently shorted to a voltage below VDD/2,
this circuitry shuts off the output devices and turns on a
smaller device in its place. A timeout period of about 50ns
is used in order to maintain normal high frequency operation, even under heavy capacitive loads (>100mA transient current into the load).
CABLE
DELAY
DRIVER
INPUT
2V/DIV
RECEIVER
INPUT
5V/DIV
RECEIVER
OUTPUT
NOTES:
TOP TRACE: LTC1685 DRIVER INPUT
MID TRACE: LTC1518 INPUT AT FAR END
OF 100ft CATAGORY 5 UTP
BOTTOM TRACE: LTC1518 OUTPUT
50ns/DIV
LTC1518/19 • F09
Figure 9. 20ns Pulse Propagating Down 100ft of Category 5 UTP
1V/DIV
RECEIVER
INPUT
5V/DIV
RECEIVER
OUTPUT
NOTES:
TOP TRACE: LTC1518 INPUT AT FAR END
OF 100ft CAT 5 UTP
BOTTOM TRACE: LTC1518 OUTPUT
20ns/DIV
LTC1518/19 • F10
Figure 10. 52Mbps Pulse Train Over 100ft of Category 5 UTP
10
LTC1518/LTC1519
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
S Package
16-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.386 – 0.394*
(9.804 – 10.008)
16
15
14
13
12
11
10
9
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
1
0.010 – 0.020
× 45°
(0.254 – 0.508)
2
3
4
5
6
0.053 – 0.069
(1.346 – 1.752)
0.008 – 0.010
(0.203 – 0.254)
0.014 – 0.019
(0.355 – 0.483)
TYP
8
0.004 – 0.010
(0.101 – 0.254)
0° – 8° TYP
0.016 – 0.050
(0.406 – 1.270)
7
0.050
(1.270)
BSC
S16 1098
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
11
LTC1518/LTC1519
U
TYPICAL APPLICATIO
High Speed Receiver with Hot Swap Control
BACK
PLANE
PLUG-IN
CARD
R1
0.005Ω
Q1
MTB56N06V
VCC
5V
5A
VCC
+
R3
6.81k
1%
R2
10Ω
5%
8
2
SENSE
VCC
C1
0.1µF
6
GATE
FB
ON
CONNECTOR 1
CONNECTOR 2
ON/RESET
7
R4
2.43k
1%
5
µP
LTC1422
RESET
TIMER
C4
2200µF
1
RESET
GND
3
4
C2
0.33µF
3.3k
GND
8
DATA
BUS
2
LTC1518
+
1
–
6
+
7
–
10
+
9
–
14
+
15
–
16
4
3
5
3.3k
0.1µF
D7
D6
11
13
D5
D4
8
2
LTC1518
+
1
–
6
+
7
–
10
+
9
–
14
+
15
8
–
16
4
3
5
D3
D2
11
13
D1
D0
1518 TA03
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC486/LTC487
Low Power Quad RS485 Drivers
10Mbps, – 7V to 12V Common Mode Range
LTC488/LTC489
Low Power Quad RS485 Receivers
10Mbps, – 7V to 12V Common Mode Range
LT®1016
UltraFastTM Precision Comparator
Single 5V Supply, 10ns Propagation Delay
LTC1520
High Speed, Precision Quad Differential Line Receiver
50Mbps, ±100mV Threshold, Rail-to-Rail Common Mode
LTC1685/LTC1686/
LTC1687
High Speed, Precision RS485 Transceivers
52Mbps, Pin Compatible with LTC485/490/491
LTC1688/LTC1689
High Speed, RS485 Quad Drivers
100Mbps, Pin Compatible with LTC486/LTC487
UltraFast is a trademark of Linear Technology Corporation.
12
Linear Technology Corporation
15189fa LT/TP 0900 2K REV A • PRINTED IN THE USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com
 LINEAR TECHNOLOGY CORPORATION 1997