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

LTC1694
SMBus/I²C Accelerator
FEATURES
s _{Improves SMBus Rise Time Transition}
s _{Ensures Data Integrity with Multiple Devices}
on the SMBus
s _{Improves Low State Noise Margin}
s _{Auto Detect Low Power Standby Mode}
s _{Wide Supply Voltage Range: 2.7V to 6V}
s _{Tiny 5-Pin SOT-23 Package}
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 LT C^®1694 is a dual SMBus active pull-up designed to
enhance data transmission speed and reliability under all
specified SMBus loading conditions. The LTC1694 is also
compatible with the Philips I²C^TM Bus.
The LTC1694 allows multiple device connections or a
longer, more capacitive interconnect, without compro-
mising slew rates or bus performance, by using two
bilevel hysteretic current source pull-ups.
During positive bus transitions, the LTC1694 current
sources provide 2.2mA to quickly slew the SMBus line.
During negative transitions or steady DC levels, the cur-
rent sources decrease to 275µA to improve negative slew
rate and improve low state noise margins. An auto detect
standby mode reduces supply current if both SCL and
SDA are high.
The LTC1694 is available in a 5-pin SOT-23 package,
requiring virtually the same space as two surface mount
resistors.
, 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
2
4
GND SMBus2
SCL
SMBus _SDA
CLK
IN
CLK
OUT
DEVICE 1
DATA
IN
DATA
OUT
CLK
IN
CLK
OUT
DEVICE N
DATA
IN
DATA
OUT
LTC1694: Patent Pending
1694 TA01
Comparison of SMBus Waveforms for
the LTC1694 vs Resistor Pull-Up
1V/DIV
LTC1694
R_PULL-UP
= 15.8k
V_CC = 5V
C_LD = 200pF
f_SMBus = 100kHz
1µs/DIV
1694 TA02
1