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Texas Instruments TCA4311ADGKR
- Part No.:
- TCA4311ADGKR
- Manufacturer:
- Texas Instruments
- Category:
- Signal Buffers, Repeaters, Splitters
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
TCA4311ADGKR.pdf
- Description:
- IC REDRIVER I2C HOTSWAP 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:11,435
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Product details
Overview
TCA4311ADGKR from Texas Instruments is a hot-swappable bidirectional I²C/SMBus buffer IC designed for live insertion of add-on cards into active backplanes. It operates from 2.7 V to 5.5 V, provides 1-V precharge on SDA/SCL lines, isolates backplane and card bus capacitances, and supports Standard-Mode (100 kHz) and Fast-Mode (400 kHz) I²C traffic in telecom switching equipment and industrial automation systems.
For engineers reviewing the TCA4311ADGKR datasheet, TCA4311ADGKR pinout, TCA4311ADGKR application, or TCA4311ADGKR equivalent, key selection considerations include its EN-controlled shutdown (<1 μA), READY open-drain status flag, rise-time accelerator support for weak pull-ups, bidirectional buffering with input-output offset voltage control, and robust hot-swap sequencing for live backplane integration.
Technical Context
The TCA4311ADGKR implements a controlled connection circuitry that waits for bus idle or STOP condition before linking SDAIN/SDAOUT and SCLIN/SCLOUT - preventing bus contention during live insertion. Its undervoltage lockout (UVLO) activates below 2.5 V, and pre-charge circuitry applies 1 V via 100-kΩ resistors to all I²C pins during power-up or hot insertion.
It integrates rise-time accelerators delivering ~2 mA transient current per SDA/SCL line above 0.6 V to meet I²C rise-time requirements with higher-value pull-up resistors. The READY pin signals connection completion, while EN enables low-current disable mode that isolates both sides, disables accelerators, and drives READY low.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 2.7 V to 5.5 V - supports mixed-voltage backplane-to-card interfaces without level-shifting. |
| Pre-charge Voltage | 0.8–1.2 V - minimizes voltage differential and current surge during live card insertion. |
| Bus Idle Detection | 50–150 μs - ensures safe connection only after backplane bus activity ceases. |
| Enable Time (tEN) | 95 μs - defines maximum delay from EN high to READY assertion and functional enablement. |
| Shutdown Current | <0.1 μA - enables ultra-low-power system-level power gating via EN pin. |
| Input-Output Offset | 0–175 mV - predictable voltage shift between sides, critical for ACK/NACK timing integrity. |
| Rise-Time Accelerator | 1–8 mA (typ.) - boosts rising edge slew rate to meet 1.25 V/μs I²C requirement with weaker pull-ups. |
Pinout & Package
VSSOP-8 package (3.00 mm × 3.00 mm), thermally enhanced for compact add-on card layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| EN (Pin 1) | Active-high chip enable | Drives device into sub-1-μA shutdown when low; must be high for bus connection and READY assertion. |
| SCLOUT (Pin 2) | Serial clock output | Connects to SCL bus on I/O card; mirrors SCLIN when READY is high. |
| SCLIN (Pin 3) | Serial clock input | Connects to SCL bus on backplane; isolated from SCLOUT until bus idle detected. |
| GND (Pin 4) | Supply ground | Common reference for all logic and I/O; bypass capacitor required at VCC. |
| READY (Pin 5) | Open-drain connection flag | High = backplane and card sides connected; requires external 10-kΩ pull-up to VCC. |
| SDAIN (Pin 6) | Serial data input | Connects to SDA bus on backplane; electrically isolated from SDAOUT until READY high. |
| SDAOUT (Pin 7) | Serial data output | Connects to SDA bus on I/O card; bidirectionally coupled to SDAIN post-connection. |
| VCC (Pin 8) | Power supply input | Supplies backplane-side logic; powers internal pre-charge, accelerators, and READY driver. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional I²C buffering | Preserves clock stretching, arbitration, and ACK/NACK protocols across isolated bus segments. |
| 1-V precharge circuitry | Reduces inrush current and prevents bus corruption during mechanical mating of live backplane connectors. |
| Rise-time accelerators | Enables use of ≥10-kΩ pull-up resistors while meeting I²C 1.25 V/μs rise-time spec - lowering power by >30% vs standard buffers. |
| Powered-off high-impedance I/O | SDA/SCl pins float to high-Z when VCC = 0 V - avoids backfeeding or loading powered-down backplane. |
| Open-drain READY output | Provides system-level visibility into hot-swap state for FPGA/CPLD control logic or supervisor ICs. |
Applications
| Telecom Backplane Hot-Swap | Industrial I/O Module Expansion |
|---|---|
Use Scenario: Inserting PCIe or CompactPCI I/O cards into live telecom switching racks without disrupting ongoing I²C-based sensor monitoring or fan control. IC Role / Device Role / Timing Role: Acts as a hot-swap controller and bidirectional I²C repeater, decoupling card-side capacitance from backplane bus timing. Use Value: Enables zero-downtime field upgrades and modular hardware maintenance in carrier-grade infrastructure. | Use Scenario: Adding analog input/output modules to programmable logic controllers (PLCs) in factory automation systems where main backplane remains operational. IC Role / Device Role / Timing Role: Buffers SMBus communication between PLC CPU and hot-pluggable I/O cards while maintaining strict timing for real-time diagnostics. Use Value: Eliminates need for system-wide reset during module replacement - preserving process continuity and reducing MTTR. |
| Server Baseboard Management | Data Center Power Shelf Monitoring |
Use Scenario: Integrating FRU (Field Replaceable Unit) sensors and DIMM SPD EEPROMs into server motherboards using SMBus, with hot-swap capability for serviceability. IC Role / Device Role / Timing Role: Isolates baseboard management controller (BMC) SMBus from peripheral card buses, enabling independent power domains and fault containment. Use Value: Prevents single-point bus failure from cascading across multiple FRUs - improving system reliability and service isolation. | Use Scenario: Connecting distributed power shelf controllers to centralized rack management via I²C backplane, supporting live replacement of AC/DC modules. IC Role / Device Role / Timing Role: Provides galvanically isolated (capacitive) I²C extension with precharge and READY signaling for safe power module insertion/removal. Use Value: Ensures uninterrupted power telemetry and thermal management during dynamic load balancing and redundancy switchover. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar I²C hot-swap buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TCA4311AD | SOIC-8 package (4.90 mm × 3.91 mm); identical electrical specs and pinout; higher thermal resistance (RθJA = 109.2°C/W vs 158.6°C/W). | Preferred for through-hole prototyping or legacy PCBs with SOIC footprints; less suitable for space-constrained add-on cards. | Select TCA4311AD if board layout accommodates larger SOIC and thermal margin allows. |
| PCA9515ADP | Single-channel I²C repeater with integrated level shifting (1.8–5.5 V); no precharge or READY signal; supports only unidirectional clock forwarding in some configurations. | Used where voltage translation between domains is required, but lacks hot-swap sequencing and live-insertion safety features. | Choose PCA9515ADP only when level shifting is mandatory and hot-swap control is handled externally. |
Compared with TCA4311ADGKR, the TCA4311AD offers identical functionality in a larger SOIC package better suited for manual assembly, while the PCA9515ADP trades hot-swap safety and READY signaling for voltage translation - making it unsuitable as a drop-in replacement in live-insertion systems requiring bus precharge and connection status feedback.
Availability
TCA4311ADGKR is available at Aetrix Electronics and suitable for telecom switching equipment, industrial PLC expansion, server FRU management, and data center power shelf monitoring requiring stable component supply and long-term production continuity.
Supply support for TCA4311ADGKR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor company specializing in analog, embedded processing, and connectivity technologies, with leadership in industrial, automotive, and communications markets.
The TCA4311A product line was engineered specifically for hot-swappable I²C/SMBus backplane architectures - addressing live insertion reliability, bus capacitance isolation, and system-level fault containment in modular electronics.
FAQ
What is the primary function of the TCA4311ADGKR in a hot-swap system?
The TCA4311ADGKR serves as a controlled bidirectional I²C/SMBus buffer that prevents bus corruption during live insertion of add-on cards into active backplanes. It uses 1-V precharge, bus idle detection, and sequenced connection to isolate card and backplane capacitances until safe conditions are met - ensuring uninterrupted communication. The TCA4311ADGKR achieves this while maintaining full protocol compliance including clock stretching and arbitration.
How does the READY pin on the TCA4311ADGKR indicate system status?
The READY pin on the TCA4311ADGKR is an open-drain output that goes high only when two conditions are satisfied: EN is high and the internal start-up sequence has completed (i.e., bus idle detected and SDAOUT/SCLOUT voltages verified high). When low, it indicates either EN is inactive or connection is pending. A 10-kΩ pull-up resistor to VCC is required. This signal enables host controllers to synchronize firmware initialization with physical bus readiness in the TCA4311ADGKR.
Can the TCA4311ADGKR operate with different supply voltages on the backplane and card sides?
Yes - the TCA4311ADGKR supports independent 2.7 V to 5.5 V supplies on backplane (VCC) and card sides, with no restriction on which voltage is higher. Its open-drain I²C interfaces and internal level-tolerant design allow interoperability between mixed-voltage domains without external level shifters. However, pull-up resistors must be placed on each side referenced to their respective local VCC, and the TCA4311ADGKR itself is powered only from the backplane VCC pin.
What is the purpose of the rise-time accelerators in the TCA4311ADGKR?
The rise-time accelerators in the TCA4311ADGKR deliver up to 8 mA of transient current during positive SDA/SCL transitions to meet I²C rise-time requirements (≥1.25 V/μs) using higher-value pull-up resistors - reducing static power consumption by up to 40% compared to standard buffers. They activate above ~0.6 V and are disabled during shutdown (EN low). This feature directly improves thermal performance and extends battery life in portable or dense add-on card applications using the TCA4311ADGKR.
Does the TCA4311ADGKR support Fast-Mode Plus (1 MHz) I²C operation?
No - the TCA4311ADGKR is specified only for Standard-Mode (100 kHz) and Fast-Mode (400 kHz) I²C operation, as confirmed in the official datasheet's Features and Description sections. It does not guarantee timing compliance or signal integrity at 1 MHz. For Fast-Mode Plus applications, designers must select alternative repeaters explicitly rated for 1 MHz, as the TCA4311ADGKR's propagation delays and rise-time accelerator behavior are not characterized beyond 400 kHz.
TCA4311ADGKR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Buffer, Accelerator
- Applications:
- I2C - Hotswap
- Input:
- 2-Wire Bus
- Output:
- 2-Wire Bus
- Data Rate (Max):
- -
- Number of Channels:
- 1
- Delay Time:
- -
- Signal Conditioning:
- -
- Capacitance - Input:
- 10 pF
- Voltage - Supply:
- 2.7V ~ 5.5V
- Current - Supply:
- 5.1mA
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-VSSOP
TCA4311ADGKR FAQ
1.How can I place an order for TCA4311ADGKR through Aetrix?
Please submit a Request for Quotation (RFQ) for TCA4311ADGKR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for TCA4311ADGKR reliable?
The price and inventory of TCA4311ADGKR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TCA4311ADGKR is usually 5 days.
3.What payment methods are accepted for TCA4311ADGKR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TCA4311ADGKR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TCA4311ADGKR?
TCA4311ADGKR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TCA4311ADGKR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for TCA4311ADGKR?
For technical support, including TCA4311ADGKR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TCA4311ADGKR requirements.
6.How does Aetrix verify that TCA4311ADGKR is sourced from the original manufacturer or authorized distributors?
All TCA4311ADGKR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TCA4311ADGKR meets industry standards.
7.What is the process for return or replacement of TCA4311ADGKR?
All TCA4311ADGKR units undergo pre-shipment inspection (PSI). If there is an issue with TCA4311ADGKR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The TCA4311ADGKR part is unused and in its original packaging.
Return procedure for TCA4311ADGKR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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