LTC1694-1 Datasheet, PDF (1/8 Pages) Linear Technology – SMBus/I2C Accelerator

LTC1694-1
SMBus/I²C Accelerator
FEATURES
s _{Improves SMBus/I}²_C^TM _{Rise Time Transition}
s _{Ensures Data Integrity with Multiple Devices}
on the SMBus/I²C
s _{Improves Low State Noise Margin}
s _{Wide Supply Voltage Range: 2.7V to 6V}
s _{Tiny 5-Pin SOT-23 Package}
s _{Parallel Multiple LTC1694-1 Devices}
for Increased Drive
U
APPLICATIO S
s _{Notebook and Palmtop Computers}
s _{Portable Instruments}
s _{Battery Chargers}
s _{Industrial Control Application}
s _{TV/Video Products}
s _{ACPI SMBus Interface}
DESCRIPTIO
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 I²C 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 I²C 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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
I²C is a trademark of Philips Electronics N.V.
TYPICAL APPLICATIO
V_CC
5V ₁
5
V_CC SMBus1
C1
0.1µF
LTC1694-1
2
4
GND SMBus2
SCL
SMBus _SDA
CLK
IN
CLK
OUT
DEVICE 1
DATA
IN
DATA
OUT
CLK
IN
CLK
OUT
DEVICE N
V_CC
5V
R_P1 R_P2
DATA
IN
DATA
OUT
1694-1 TA01
LTC1694-1: Patent Pending
Comparison of SMBus Waveforms for
the LTC1694-1 vs Resistor Pull-Up
LTC1694-1
1V/DIV
R_PULL-UP
= 15.8k
V_CC = 5V
C_LD = 200pF
f_SMBus = 100kHz
1µs/DIV
1694-1 TA02
1