LTC4311 Datasheet, PDF (1/12 Pages) Linear Technology – Low Voltage I2C/SMBus Accelerator

LTC4311
Low Voltage I²C/SMBus
Accelerator
FEATURES
■ _{Improves I}²_{C Bus Rise Time Transition}
■ _{Ensures Data Integrity with Multiple Devices on the}
I²C Bus.
■ _{Wide Supply Voltage Range: 1.6V to 5.5V}
■ _{Improves Low State Noise Margin}
■ _{Up to 400kHz Operation}
■ _{Auto Detect Low Power Standby Mode}
■ _{Low (<5μA) Supply Current Shutdown}
■ _{Does Not Load Bus When Disabled or Powered Down}
■ _{Strong Slew Limited Pull-up Current}
■ _{±8kV Human Body Model ESD Ruggedness}
■ _{2mm × 2mm DFN and SC70 Packages}
APPLICATIONS
■ _{Notebook and Palmtop Computers}
■ _{Portable Instruments}
■ _{Battery Chargers}
■ _{Industrial Controls}
■ _{TV/Video Products}
■ _{ACPI SMBus Interface}
DESCRIPTION
The LTC^®4311 is a dual I²C active pull-up designed to
enhance data transmission speed and reliability for bus
loading conditions well beyond the 400pF I²C specification
limit. The LTC4311 operates at supply voltages from 1.6V
to 5.5V and is also compatible with SMBus.
The LTC4311 allows multiple device connections or a lon-
ger, more capacitive interconnect, without compromising
slew rates or bus performance, by using two slew limited
pull-up currents.
During positive bus transitions, the LTC4311 provides slew
limited pull-up currents to quickly slew the I²C or SMBus
lines to the bus pull-up voltage. During negative transitions
or steady DC levels, the currents are disabled 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. When disabled, the LTC4311
goes into low (<5μA) current shutdown.
The LTC4311 is available in the 2mm × 2mm × 0.75mm
DFN, and SC70 packages.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All
other trademarks are the property of their respective owners. Protected by U.S. Patents
including 6356140 and 6650174.
TYPICAL APPLICATION
V_CC
2.5V
C1
0.01μF
I²C
SCL
SDA
CLK
IN
CLK
OUT
DEVICE 1
LTC4311
V_CC
BUS1
ENABLE
GND
BUS2
DATA
IN
DATA
OUT
V_CC
2.5V
10k 10k
CLK
IN
CLK
OUT
DEVICE N
DATA
IN
DATA
OUT
4311 TA01a
Comparison of I²C Waveforms for
the LTC4311 vs Resistor Pull-Up
1V/DIV
LTC4311
R_PULL-UP = 15.8k
V_CC = 5V
C_LD = 200pF
f_I²_C = 100kHz
1μs/DIV
4311 TA01b
4311fa
1