LTC4300A-3 Datasheet, PDF (1/12 Pages) Linear Technology – Level Shifting Hot Swappable 2-Wire Bus Buffer with Enable

FEATURES
■ _{Bidirectional Buffer* for SDA and SCL Lines}
Increases Fanout
■ _{Prevents SDA and SCL Corruption During Live}
Board Insertion and Removal from Backplane
■ _{Logic Threshold ENABLE Input}
■ _{Isolates Input SDA and SCL Lines from Output}
■ _{Compatible with I}²_C^TM_{, I}²_{C Fast Mode and SMBus}
Standards (Up to 400kHz Operation)
■ _{1V Precharge on all SDA and SCL Lines}
■ _{Supports Clock Stretching, Arbitration and}
Synchronization
■ _{5V to 3.3V Level Translation}
■ _{High Impedance SDA, SCL Pins for VCC = 0V,}
V_CC2 = 0V
■ _{Small 8-Pin DFN and MSOP Packages}
U
APPLICATIO S
■ _{Hot Board Insertion}
■ _Servers
■ _{Capacitance Buffer/Bus Extender}
■ _{Desktop Computer}
LTC4300A-3
Level Shifting
Hot Swappable 2-Wire
Bus Buffer with Enable
DESCRIPTIO
The LTC^®4300A-3 hot swappable 2-wire bus buffer allows
I/O card insertion into a live backplane without corruption
of the data and clock busses. When the connection is
made, the LTC4300A-3 provides bidirectional buffering,
keeping the backplane and card capacitances isolated.
Rise-time accelerator circuitry allows the use of weaker
DC pull-up currents while still meeting rise-time require-
ments. During insertion, the SDA and SCL lines are
precharged to 1V to minimize bus disturbances.
The LTC4300A-3 provides level translation between 3.3V
and 5V supplies. The backplane and card can both be
powered with supplies ranging from 2.7V to 5.5V. The
LTC4300A-3 also incorporates a CMOS threshold ENABLE
pin which forces the part into a low current mode and iso-
lates the card from the backplane. When driven to V_CC, the
ENABLE pin sets normal operation.
The LTC4300A-3 is available in the MSOP and 3mm × 3mm
DFN packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
*Patent pending.
TYPICAL APPLICATIO
V_CC
3.3V
SCLIN
10k 10k ₈
3
0.01µF
1
10k 10k
V_CC2
0.01µF
2
SCLOUT
6
SDAIN
7
SDAOUT
OFF ON
5
LTC4300A-3
ENABLE _GND
4
4300A-3 TA01
OUTPUT
SIDE
50pF
0.5V/DIV
Input–Output Connection
INPUT
SIDE
150pF
200ns/DIV
4300A TA02
sn4300a3 4300a3fs
1