LTC4300A-1/LTC4300A-2
Hot Swappable
2-Wire Bus Buffers
FEATURES DESCRIPTION
n
Bidirectional Buffer for SDA and SCL Lines The LTC 4300A series hot swappable 2-wire bus buffers
Increases Fanout allow I/O card insertion into a live backplane without corrup-
n
Prevents SDA and SCL Corruption During Live tion of the data and clock busses. When the connection is
Board Insertion and Removal from Backplane made, the LTC4300A-1/LTC4300A-2 provide bidirectional
n
Isolates Input SDA and SCL Lines from Output buffering, keeping the backplane and card capacitances
2 2
n
Compatible with I C, I C Fast Mode and SMBus isolated. Rise-time accelerator circuitry* allows the use of
Standards (Up to 400kHz Operation) weaker DC pull-up currents while still meeting rise-time
n
Low I Chip Disable: <1A (LTC4300A-1) requirements. During insertion, the SDA and SCL lines are
CC
n
READY Open Drain Output (LTC4300A-1) precharged to 1V to minimize bus disturbances.
n
1V Precharge on all SDA and SCL Lines
The LTC4300A-1 incorporates a CMOS threshold digital
n
Supports Clock Stretching, Arbitration and
ENABLE input pin, which forces the part into a low current
Synchronization
mode when driven to ground and sets normal operation
n
5V to 3.3V Level Translation (LTC4300A-2)
when driven to V . It also includes an open drain READY
CC
n
High Impedance SDA, SCL Pins for V = 0V
CC
output pin, which indicates that the backplane and card
n
Small MSOP 8-Pin Package
sides are connected together. The LTC4300A-2 replaces
the ENABLE pin with a dedicated supply voltage pin, V ,
CC2
APPLICATIONS
for the card side, providing level shifting between 3.3V
and 5V systems. Both the backplane and card may be
n
Hot Board Insertion
powered with supply voltages ranging from 2.7V to 5.5V,
n
Servers
with no constraints on which supply voltage is higher. The
n
Capacitance Buffer/Bus Extender
LTC4300A-2 also replaces the READY pin with a digital
n
Desktop Computer
CMOS input pin, ACC, which enables and disables the
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot
rise-time accelerator currents.
Swap and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are
the property of their respective owners. *Protected by U.S. Patents, including 6650174.
The LTC4300A is available in a small 8-pin MSOP package.
TYPICAL APPLICATION
V
CC InputOutput Connection t
PLH
3.3V
C1
0.01F
R1 R2 R3 R4
10k 10k 10k 10k
OUTPUT INPUT
SIDE SIDE
SCLIN SCLOUT
50pF 150pF
SDAIN SDAOUT
LTC4300A-1
ENABLE READY
4300a12 TA02
GND
4300a12 TA01
4300a12fa
1LTC4300A-1/LTC4300A-2
ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION
(Note 1)
TOP VIEW
V to GND .................................................... 0.3 to 7V
CC
ENABLE/V * 1 8 V
CC2 CC
SCLOUT 2 7 SDAOUT
V to GND (LTC4300A-2)............................ 0.3 to 7V
CC2
SCLIN 3 6 SDAIN
SDAIN, SCLIN, SDAOUT, SCLOUT .................. 0.3 to 7V
GND 4 5 READY/ACC*
READY, ENABLE (LTC4300A-1) ...................... 0.3 to 7V
MS8 PACKAGE
8-LEAD PLASTIC MSOP
ACC (LTC4300A-2) ......................................... 0.3 to 7V
*LTC4300A-2
T = 125C, = 200C/W
Operating Temperature Range JMAX JA
LTC4300A-1C/LTC4300A-2C .................... 0C to 70C
LTC4300A-1I/LTC4300A-2I ..................40C to 85C
Storage Temperature Range .................. 65C to 125C
Lead Temperature (Soldering, 10 sec) ...................300C
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC4300A-1CMS8#PBF LTC4300A-1CMS8#TRPBF LTABF 8-Lead Plastic MSOP 0C to 70C
LTC4300A-1IMS8#PBF LTC4300A-1IMS8#TRPBF LTABG 8-Lead Plastic MSOP 40C to 85C
LTC4300A-2CMS8#PBF LTC4300A-2CMS8#TRPBF LTACF 8-Lead Plastic MSOP 0C to 70C
LTC4300A-2IMS8#PBF LTC4300A-2IMS8#TRPBF LTACG 8-Lead Plastic MSOP 40C to 85C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: