Datasheet

1
LTC1694-1
16941fa
SMBus/I
2
C Accelerator*
■
Improves SMBus/I
2
C
TM
Rise Time Transition
■
Ensures Data Integrity with Multiple Devices
on the SMBus/I
2
C
■
Improves Low State Noise Margin
■
Wide Supply Voltage Range: 2.7V to 6V
■
Parallel Multiple LTC1694-1 Devices
for Increased Drive
■
Low Profile (1mm) SOT-23 (ThinSOT
TM
) Package
The LTC
®
1694-1 is a dual SMBus active pull-up designed
to enhance data transmission speed and reliability under
all specified SMBus loading conditions. The LTC1694-1 is
also compatible with the Philips I
2
C Bus.
The LTC1694-1 allows multiple device connections or a
longer, more capacitive interconnect, without compro-
mising slew rates or bus performance, by supplying a high
pull-up current of 2.2mA to slew the SMBus or I
2
C lines
during positive bus transitions
During negative transitions or steady DC levels, the
LTC1694-1 sources zero current. External resistors, one
on each bus line, trigger the LTC1694-1 during positive
bus transitions and set the pull-down current level. These
resistors determine the slew rate during negative bus
transitions and the logic low DC level.
The LTC1694-1 is available in a 5-pin SOT-23 package.
■
Notebook and Palmtop Computers
■
Portable Instruments
■
Battery Chargers
■
Industrial Control Application
■
TV/Video Products
■
ACPI SMBus Interface
, LTC and LT are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
I
2
C is a trademark of Philips Electronics N.V.
*U.S. Patent No. 6,650,174
V
CC
= 5V 1µs/DIV 1694-1 TA02
C
LD
= 200pF
f
SMBus
= 100kHz
Comparison of SMBus Waveforms for
the LTC1694-1 vs Resistor Pull-Up
LTC1694-1
1V/DIV
R
PULL-UP
= 15.8k
LTC1694-1
V
CC
GND
V
CC
5V
C1
0.1µF
SMBus1
SMBus2
SCL
SDA
DEVICE 1
CLK
IN
CLK
OUT
SMBus
V
CC
5V
DATA
IN
DATA
OUT
DEVICE N
1694-1 TA01
CLK
IN
R
P2
CLK
OUT
DATA
IN
DATA
OUT
R
P1
DESCRIPTIO
U
FEATURES
APPLICATIO S
U
TYPICAL APPLICATIO
U