Datasheet LTC4302-1, LTC4302-2 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | Addressable 2-Wire Bus Buffers |
| Seiten / Seite | 20 / 1 — FEATURES. DESCRIPTIO. Bidirectional Buffer for SDA and SCL Lines. … |
| Dateiformat / Größe | PDF / 305 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTIO. Bidirectional Buffer for SDA and SCL Lines. Increases Fanout. Connect SDA and SCL Lines with 2-Wire Bus
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LTC4302-1/LTC4302-2 Addressable 2-Wire Bus Buffers
U FEATURES DESCRIPTIO
■
Bidirectional Buffer for SDA and SCL Lines
The LTC®4302-1/LTC4302-2 addressable I2C bus and
Increases Fanout
SMBus compatible bus buffers allow a peripheral board ■
Connect SDA and SCL Lines with 2-Wire Bus
to be inserted and removed from a live backplane without
Commands
corruption of the bus. The LTC4302-1/LTC4302-2 main- ■
Prevents SDA and SCL Corruption During Live Board
tain electrical isolation between the backplane and periph-
Insertion and Removal from Backplane
eral board until their VCC supply is valid and a master ■
Compatible with I2CTM Standard Mode, I2C Fast
device on the backplane side addresses the LTC4302-1/
Mode and SMBus Standards
LTC4302-2 and commands them to connect. The ■ Rise Time Accelerators on SDA, SCL Lines LTC4302-1/LTC4302-2’s ADDRESS pin provides 32 pos- ■ 1V Precharge on SDA and SCL Lines sible addresses set by an external resistive divider be- ■ 32 Unique Addresses from a Single ADDRESS Pin tween VCC and GND. The LTC4302-1/LTC4302-2 work ■ Two General Purpose Inputs-Outputs (LTC4302-1) with supply voltages ranging from 2.7V to 5.5V. The SDA ■ Translates Between 5V and 3.3V Systems and SCL inputs and outputs do not load the bus lines when (LTC4302-2) VCC is low. ■ Small 10-Pin MSOP Package Rise time accelerator circuitry* allows for heavier capaci-
U
tive bus loading while still meeting system timing require-
APPLICATIO S
ments. During insertion, the SDA and SCL lines are precharged to 1V to minimize bus disturbances. Two ■ Live Board Insertion general purpose input/output pins (GPIOs) on the ■ 5V/3.3V Level Translator LTC4302-1 can be configured as inputs, open-drain out- ■ Servers puts or push-pull outputs. The LTC4302-2 option replaces ■ Capacitance Buffer/Bus Extender one GPIO pin with a second supply voltage pin VCC2, ■ Nested Addressing providing level shifting between systems with different , LTC and LT are registered trademarks of Linear Technology Corporation. supply voltages. The LTC4302-1/LTC4302-2 are available I2C is a trademark of Philips Electronics N.V. *U.S. Patent No. 6,650,174 in a 10-pin MSOP package.
U TYPICAL APPLICATIO Input-Output Connection tPLH
2.7V to 5.5V C1 R3 R4 R1 R5 0.01µF R6 R7 R8 R9 V 10k 10k 1870Ω 10k CC 10k 10k 1k 1k LTC4302-1 OUTPUT INPUT SDA CARD SDA SDAIN SDAOUT SIDE SIDE SCL CARD SCL 50pF 150pF SCLIN SCLOUT CONN LED ADDRESS GPIO2 LED R2 GPIO1 2000Ω 4203 TA01a GND 4032 F10 0.1µs/DIV sn430212 430212fs 1
U FEATURES DESCRIPTIO
■
Bidirectional Buffer for SDA and SCL Lines
The LTC®4302-1/LTC4302-2 addressable I2C bus and
Increases Fanout
SMBus compatible bus buffers allow a peripheral board ■
Connect SDA and SCL Lines with 2-Wire Bus
to be inserted and removed from a live backplane without
Commands
corruption of the bus. The LTC4302-1/LTC4302-2 main- ■
Prevents SDA and SCL Corruption During Live Board
tain electrical isolation between the backplane and periph-
Insertion and Removal from Backplane
eral board until their VCC supply is valid and a master ■
Compatible with I2CTM Standard Mode, I2C Fast
device on the backplane side addresses the LTC4302-1/
Mode and SMBus Standards
LTC4302-2 and commands them to connect. The ■ Rise Time Accelerators on SDA, SCL Lines LTC4302-1/LTC4302-2’s ADDRESS pin provides 32 pos- ■ 1V Precharge on SDA and SCL Lines sible addresses set by an external resistive divider be- ■ 32 Unique Addresses from a Single ADDRESS Pin tween VCC and GND. The LTC4302-1/LTC4302-2 work ■ Two General Purpose Inputs-Outputs (LTC4302-1) with supply voltages ranging from 2.7V to 5.5V. The SDA ■ Translates Between 5V and 3.3V Systems and SCL inputs and outputs do not load the bus lines when (LTC4302-2) VCC is low. ■ Small 10-Pin MSOP Package Rise time accelerator circuitry* allows for heavier capaci-
U
tive bus loading while still meeting system timing require-
APPLICATIO S
ments. During insertion, the SDA and SCL lines are precharged to 1V to minimize bus disturbances. Two ■ Live Board Insertion general purpose input/output pins (GPIOs) on the ■ 5V/3.3V Level Translator LTC4302-1 can be configured as inputs, open-drain out- ■ Servers puts or push-pull outputs. The LTC4302-2 option replaces ■ Capacitance Buffer/Bus Extender one GPIO pin with a second supply voltage pin VCC2, ■ Nested Addressing providing level shifting between systems with different , LTC and LT are registered trademarks of Linear Technology Corporation. supply voltages. The LTC4302-1/LTC4302-2 are available I2C is a trademark of Philips Electronics N.V. *U.S. Patent No. 6,650,174 in a 10-pin MSOP package.
U TYPICAL APPLICATIO Input-Output Connection tPLH
2.7V to 5.5V C1 R3 R4 R1 R5 0.01µF R6 R7 R8 R9 V 10k 10k 1870Ω 10k CC 10k 10k 1k 1k LTC4302-1 OUTPUT INPUT SDA CARD SDA SDAIN SDAOUT SIDE SIDE SCL CARD SCL 50pF 150pF SCLIN SCLOUT CONN LED ADDRESS GPIO2 LED R2 GPIO1 2000Ω 4203 TA01a GND 4032 F10 0.1µs/DIV sn430212 430212fs 1