Datasheet LTC4300A-1, LTC4300A-2 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Hot Swappable 2-Wire Bus Buffers |
| Pages / Page | 16 / 1 — FEATURES. DESCRIPTION. Bidirectional Buffer for SDA and SCL Lines. … |
| File Format / Size | PDF / 186 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. Bidirectional Buffer for SDA and SCL Lines. Increases Fanout
Model Line for this Datasheet
Text Version of Document
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 n Compatible with I2C, I2C 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 ICC Chip Disable: <1μA (LTC4300A-1) requirements. During insertion, the SDA and SCL lines are 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 VCC. It also includes an open drain READY n High Impedance SDA, SCL Pins for VCC = 0V 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, VCC2,
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 Swap and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are rise-time accelerator currents. 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
VCC
Input–Output Connection tPLH
3.3V C1 R1 R2 0.01μF R3 R4 10k 10k 10k 10k OUTPUT INPUT SIDE SIDE SCLIN SCLOUT 50pF 150pF SDAIN SDAOUT LTC4300A-1 ENABLE READY GND 4300a12 TA02 4300a12 TA01 4300a12fa 1
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 n Compatible with I2C, I2C 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 ICC Chip Disable: <1μA (LTC4300A-1) requirements. During insertion, the SDA and SCL lines are 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 VCC. It also includes an open drain READY n High Impedance SDA, SCL Pins for VCC = 0V 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, VCC2,
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 Swap and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are rise-time accelerator currents. 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
VCC
Input–Output Connection tPLH
3.3V C1 R1 R2 0.01μF R3 R4 10k 10k 10k 10k OUTPUT INPUT SIDE SIDE SCLIN SCLOUT 50pF 150pF SDAIN SDAOUT LTC4300A-1 ENABLE READY GND 4300a12 TA02 4300a12 TA01 4300a12fa 1
