LTC1688CS#PBF Linear Technology, LTC1688CS#PBF Datasheet - Page 6

• Manufacturer Part Number: LTC1688CS#PBF
• Description: IC DVR 100MBPS RS485 QUAD 16SOIC
• Manufacturer: Linear Technology
• Type: Driverr

Specifications of LTC1688CS#PBF

• Number Of Drivers/receivers: 4/0
• Protocol: RS485
• Voltage - Supply: 3V, 5V
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Device Type: Differential
• Interface Type: RS422, RS485
• No. Of Drivers: 4
• Supply Voltage Range: 3V To 5.25V
• Driver Case Style: SOIC
• No. Of Pins: 16
• Operating Temperature Range: 0°C To +70°C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS
LTC1688/LTC1689
SWITCHI G TI E WAVEFOR S
The LTC1688/LTC1689 family of RS485 quad differential
drivers employs a novel architecture and fabrication pro-
cess that allows ultra high speed operation (100Mbps)
and Hot Swap capability while maintaining the ruggedness
of RS485 operation (three-state outputs can float from
– 7V to 12V with a single 5V supply). Unlike typical CMOS
drivers whose propagation delay can vary as much as
500%, the propagation delay of the LTC1688/LTC1689
drivers will only vary by 50% (a narrow 4ns window).
This performance is achieved by designing the input stage
of each driver to have minimum propagation delay shift
over temperature and from part to part.
The LTC1688/LTC1689 have an ESD rating of 6kV human
body model.
50Mbps with 3V Operation
The LTC1688/LTC1689 are designed to operate with a 3V
power supply and still achieve 50Mbps operation (see
6
A, B
EN
A, B
V
V
DI
3V
0V
5V
0V
OH
OL
– V
3V
0V
V
B
A
O
O
V
O
U
U
W
INFORMATION
1/2 V
U
O
10%
t
1.5V
t
r
t
ZH
ZL
t
PLH
1.5V
W
90%
1/2 V
1/2 V
Figure 5. Driver Enable and Disable Times
DD
DD
t
SKEW
Figure 4. Driver Propagation Delays
W
U
f = 1MHz; t
OUTPUT NORMALLY HIGH
f = 1MHz; t
OUTPUT NORMALLY LOW
V
DIFF
r
= V(A) – V(B)
< 3ns; t
Electrical Characteristics table for 3V DC and AC specifica-
tions). Figure 6 shows waveforms of an LTC1689 driving
a receiver using 100 feet of Category 5 UTP. Both parts are
operating at 3V supply.
r
3ns; t
f
< 3ns
f
2V/DIV
2V/DIV
5V/DIV
3ns
Figure 6. 3V High Speed Data Transmission
FAR END OF CABLE
RECEIVER OUTPUT
LTC1689 OUTPUT
1/2 V
20ns/DIV
O
t
t
HZ
LZ
1.5V
t
PHL
1.5V
t
f
90%
10%
0.5V
0.5V
t
1688/89 F06
SKEW
1688/89 F05
1688/89 F04
16889fa