LTC4302-1 - Addressable 2-Wire Bus Buffer | Analog Devices
MPN: LTC4302-1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $2.98 | $1,490.00 |
| 1,000 | $2.65 | $2,650.00 |
LTC4302-1 Overview
A 2-wire bus buffer is an integrated circuit that isolates and regenerates I2C or SMBus signals between a controller segment and a peripheral segment of the same bus. In the power-management hierarchy of system electronics, bus buffers sit between the host controller and the distributed peripherals, functioning as signal repeaters that allow capacitive load splitting, live-board insertion, and improved noise immunity. The LTC4302-1 belongs to the broader family of I2C buffers, SMBus buffers, and bus repeaters within mixed-signal interface ICs.
Key differentiating features include hot-swap capability that permits a peripheral board to be inserted into or removed from a live backplane without corrupting the bus, rail-to-rail input glitch filtering of up to 50 ns duration pulses, and the ADDRESS pin architecture that provides 32 possible addresses set by an external resistive divider between VCC and GND. When VCC is low, the SDA and SCL inputs and outputs do not load the bus lines, a critical behavior for multi-card backplane systems.
Technically, the LTC4302-1 uses rise-time accelerator circuitry and high noise margin level shifting on both the SDA and SCL channels. Per the Analog Devices datasheet (4302fs), the glitch filters prevent signals of up to 50 ns minimum duration and rail-to-rail voltage magnitude from passing into the 2-wire bus digital interface circuitry, ensuring robustness against backplane transients at Fast Mode 400 kHz operation.
Typical applications include live-backplane peripheral card insertion in telecom and datacenter equipment, SMBus-aware server power-supply management, and I2C bus extension where bus capacitance exceeds the 400 pF standard limit. The LTC4302-1 variant's specific offset/slope behavior suits designs where an exact DC offset on the buffered segment is required.
Design consideration: the ADDRESS pin resistive divider must use 1% or better tolerance resistors, and supply voltage must remain within 2.7V to 5.5V to guarantee glitch-filter timing and drive specifications.
This page synthesizes distributor data, drop-in same-family alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for LTC4302-1 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC4302-2
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC4311
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC4315
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC4300A-1
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC4302-1 Specifications
| Function | Addressable 2-Wire Bus Buffer |
| Bus Compatibility | I2C, SMBus |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Selectable Addresses | 32 (via ADDRESS pin resistive divider) |
| Glitch Filter | Rejects pulses up to 50 ns (minimum) duration, rail-to-rail |
| Bus Speed | 400 kHz (I2C Fast Mode) |
| High Noise Margin | Yes |
| Hot-Swap Support | Live backplane insertion/removal without bus corruption |
| Bus Loading when VCC Low | SDA/SCL I/Os do not load the bus lines |
| Channels Buffered | 2 (SDA and SCL) |
| Mounting Type | Surface Mount |
LTC4302-1 standard Pin Configuration Guide
Pin configuration for LTC4302-1 (standard package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for LTC4302-1.
Refer to the datasheet for full pin configuration.
Typical Applications
LTC4302-1 is suitable for 6 applications: Live Backplane Card Insertion, Server SMBus Power Management, I2C Bus Capacitance Extension, Telecom Equipment Chassis Management, Industrial Control Distributed Sensor Buses, Battery-Powered Portable Instrument Buses.
Live Backplane Card Insertion
The primary application of the LTC4302-1 is live insertion and removal of peripheral boards on an I2C or SMBus backplane. According to the Analog Devices datasheet, the buffer allows a card to be inserted into or removed from a live backplane without corrupting the bus. Its SDA and SCL I/Os do not load the bus lines when VCC is low, so a card sliding into a connector presents a high-impedance, non-intrusive load during the pin-make sequence. The 50 ns glitch filter absorbs connector bounce, and the 32-address ADDRESS pin lets every card slot carry its own uniquely addressed buffer, enabling hot-swap chassis designs in telecom and industrial control.
Recommended
Server SMBus Power Management
Server and storage systems use SMBus to monitor power supplies, fans, and thermal sensors across multiple hot-plug line cards. The LTC4302-1 is SMBus compatible per the Analog Devices datasheet and buffers the management bus at each card, isolating the card-side capacitance and transients from the shared chassis bus. Its 2.7V to 5.5V supply range spans both 3.3V management domains and 5V legacy rails, and the 400 kHz Fast Mode compatibility keeps monitoring poll rates high. The 32 selectable addresses allow a 32-card chassis without address conflicts between buffering stages, while the glitch filter rejects switching-regulator noise coupled into the bus.
Recommended
I2C Bus Capacitance Extension
Standard I2C limits total bus capacitance to 400 pF, which large backplanes and long ribbon-cable runs quickly exceed. Placing the LTC4302-1 between the host segment and the peripheral segment splits the bus into two independently driven halves, each within its capacitance budget. Per the Analog Devices datasheet, the buffer provides high noise margin on both segments and regenerates signal edges, restoring rise and fall times that would otherwise violate the 400 kHz Fast Mode timing. The 50 ns glitch filtering on SDAIN and SCLIN ensures noise picked up on long cable runs does not propagate into the digital interface, making the part suitable for distributed sensor buses.
Recommended
Telecom Equipment Chassis Management
Telecom shelves built to carrier-grade requirements rely on SMBus/I2C for shelf-management communication to power-entry modules and fabric cards. The LTC4302-1 supports these designs with live insertion per the Analog Devices datasheet: cards can be swapped during operation without corrupting the shared management bus, a hard requirement for -48V DC plant availability. The resistive-divider ADDRESS pin scheme provides 32 discrete addresses for shelf slots, and the rail-to-rail glitch rejection of pulses up to 50 ns duration shields the management interface from the harsh electrical environment typical of telecom backplanes, including relay transients and supply dither.
Recommended
Industrial Control Distributed Sensor Buses
In factory automation and process control, I2C links frequently run several meters across cabinets and machine segments, accumulating capacitance and noise. The LTC4302-1 buffers each segment boundary with the high noise margin described in the Analog Devices datasheet, allowing 400 kHz operation across electrically noisy motor-drive and contactor environments. The 2.7V to 5.5V supply range matches common 3.3V controller and 5V field logic domains, and the zero-load unpowered behavior lets entire sensor clusters be powered down without disturbing the upstream bus. Its glitch filter rejects the fast transients typical of inverter-driven motor systems before they reach interface logic.
Recommended
Battery-Powered Portable Instrument Buses
Portable test and measurement instruments chain multiple I2C devices across a battery-powered internal bus where rail sequencing varies during power-up and sleep transitions. The LTC4302-1's specification that SDA and SCL inputs and outputs do not load the bus when VCC is low means sub-systems held in reset or powered down never pull down the shared bus, per the Analog Devices datasheet. The 2.7V minimum supply suits single lithium-cell rails through an LDO, and the 50 ns glitch filter maintains signal integrity near wireless modules. The addressable 32-code scheme supports multiple buffered sub-systems in one instrument without host-side address management overhead.
Recommended
Recommended Products Summary
Engineering reference data for LTC4302-1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC4302-2 | LTC4311 | LTC4315 | LTC4300A-1 |
|---|---|---|---|---|---|
| Package | SOIC-8 / MSOP-8 | SOIC-8 / MSOP-8 - same | SOIC-8 - same footprint family | SOIC-8 - same footprint family | SOIC-8 - same footprint family |
| Brand | Analog Devices (Linear Technology) | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.3 V to 5.5 V | 1.4 V to 5.5 V (with level translation) | 2.3 V to 5.5 V |
| Selectable Addresses | 32 (ADDRESS pin divider) | 32 (ADDRESS pin divider) | None (non-addressable buffer) | None (non-addressable buffer) | Addressable hot-swap buffer |
| Hot-Swap / Live Insertion | Yes (live backplane insertion) | Yes | Yes (hot-swappable) | Yes (hot-swappable) | Yes |
Key Differentiators
- Addressability with 32 selectable codes (vs LTC4311)
- Specified 50 ns glitch rejection at Fast Mode speed (vs LTC4302-2)
- Zero bus loading when unpowered (vs LTC4300A-1)
Design Notes
Set the ADDRESS pin with a resistive divider between VCC and GND using 1% or better tolerance resistors. The 32-address decoding depends on the ratio of this divider; resistor drift or tolerance error can shift the decoded address and cause bus conflicts in multi-card systems. Keep the ADDRESS node short and place a small local decoupling capacitor if the trace passes near switching circuitry, since noise coupled onto the ADDRESS pin can mis-decode addresses during transients.
Decouple VCC with a 0.1 uF ceramic capacitor placed within a few millimeters of the supply pin, in addition to the bulk capacitance of the card. The LTC4302-1 operates from 2.7V to 5.5V per the Analog Devices datasheet; operation below 2.7V is not specified and glitch-filter timing may degrade before the device fully stops driving. In hot-swap slots, ensure VCC ramps monotonically - a bouncing supply during card insertion can re-trigger the buffer and briefly load the bus.
Do not assume the LTC4302-1 and LTC4302-2 are freely interchangeable: they share package, pinout, supply range, and glitch-filter specs, but the datasheet distinguishes the two by buffered-segment behavior. Substituting one for the other changes how the buffered segment interacts with downstream bus capacitance and pull-up levels. Validate the swap on the actual backplane segment, including worst-case bus capacitance and the slowest allowed rise time, before releasing the change.
Compliance Information
Compliance data was not present in the provided verified web data. Confirm RoHS/REACH status on the Analog Devices LTC4302 product page before procurement.
