TCA4311ADGKR

Order Now Product Folder Support & Community Tools & Software Technical Documents TCA4311A SCPS226C – JANUARY 2011 – REVISED AUGUST 2018 TCA4311A Hot Swappable 2-Wire Bus Buffers 1 Features 3 Description • The TCA4311A is a hot-swappable I2C bus buffer that supports I/O card insertion into a live backplane without corruption of the data and clock busses. Control circuitry prevents the backplane from being connected to the card until a stop command or bus idle occurs on the backplane without bus contention on the card. When the connection is made, this device provides bidirectional buffering, keeping the backplane and card capacitances isolated. During insertion, the SDA and SCL lines are pre-charged to 1 V to minimize the current required to charge the parasitic capacitance of the chip. 1 • • • • • • • • • • • • • • Operating Power-Supply Voltage Range of 2.7 V to 5.5 V Supports Bidirectional Data Transfer of I2C Bus Signals SDA and SCL Lines are Buffered Which Increases Fanout 1-V Precharge on all SDA and SCL Lines Prevents Corruption During Live Board Insertion and Removal From Backplane SDA and SCL Input Lines are Isolated From Outputs Accommodates Standard Mode and Fast Mode I2C Devices Improved Noise Immunity Applications Include Hot Board Insertion and Bus Extension Low ICC Chip Disable of < 1 μA READY Open-Drain Output Supports Clock Stretching, Arbitration, and Synchronization Powered-Off High-Impedance I2C Pins Open-Drain I2C Pins Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II ESD Protection Exceeds JESD 22 – 8000-V Human-Body Model (A114-A) – 200-V Machine Model (A115-A) – 1000-V Charged-Device Model (C101) When the I2C bus is idle, the TCA4311A can be put into shutdown mode by setting the EN pin low. When EN is high, the TCA4311A resumes normal operation. It also includes an open drain READY output pin, which indicates that the backplane and card sides are connected together. When READY is high, the SDAIN and SCLIN are connected to SDAOUT and SCLOUT. When the two sides are disconnected, READY is low. Both the backplane and card may be powered with supply voltages ranging from 2.7 V to 5.5 V, with no restrictions on which supply voltage is higher. The TCA4311A has standard open-drain I/Os. The size of the pull-up resistors to the I/Os depends on the system, but each side of this buffer must have a pull-up resistor. The device is designed to work with Standard Mode and Fast Mode I2C devices in addition to SMBus devices. Standard Mode I2C devices only specify 3 mA in a generic I2C system where Standard Mode devices and multiple masters are possible. Under certain conditions, high termination currents can be used. 2 Applications • • • • Device Information(1) Servers Routers (Telecom Switching Equipment) Base Stations Industrial Automation PART NUMBER TCA4311A PACKAGE BODY SIZE (NOM) SOIC (8) 4.90 mm × 3.91 mm VSSOP (8) 3.00 mm × 3.00 mm (1) For all available packages, see the orderable addendum at the end of the datasheet. Simplified Schematic VCC SDAIN SCLIN SDAOUT SCLOUT Add-on card 2 I C bus or SMBus 2 Backplane I C bus or SMBus TCA4311A EN READY GND 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. TCA4311A SCPS226C – JANUARY 2011 – REVISED AUGUST 2018 www.ti.com Table of Contents 1 2 3 4 5 6 7 8 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Pin Configuration and Functions ......................... Specifications......................................................... 1 1 1 2 3 4 6.1 6.2 6.3 6.4 6.5 6.6 4 4 4 4 5 6 Absolute Maximum Ratings ..................................... ESD Ratings.............................................................. Recommended Operating Conditions....................... Thermal Information .................................................. Electrical Characteristics .......................................... Typical Characteristics .............................................. Parameter Measurement Information .................. 6 Detailed Description .............................................. 8 8.1 Overview ................................................................... 8 8.2 Functional Block Diagram ......................................... 8 8.3 Feature Description................................................... 9 8.4 Device Functional Modes.......................................... 9 9 Application and Implementation ........................ 11 9.1 Application Information............................................ 11 9.2 Typical Application .................................................. 11 10 Power Supply Recommendations ..................... 17 11 Layout................................................................... 17 11.1 Layout Guidelines ................................................. 17 11.2 Layout Example .................................................... 18 12 Device and Documentation Support ................. 19 12.1 12.2 12.3 12.4 12.5 Receiving Notification of Documentation Updates Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 19 19 19 19 19 13 Mechanical, Packaging, and Orderable Information ........................................................... 19 4 Revision History Changes from Revision B (October 2014) to Revision C Page • Moved Tstg to the Absolute Maximum Rating table ................................................................................................................ 4 • Changed the Handling Rating table To: ESD Ratings ........................................................................................................... 4 • Added Missing ACK Event section ....................................................................................................................................... 10 Changes from Revision A (July 2012) to Revision B Page • Handling Rating table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section. ................................................................................................ 1 • Changed the TCA4311A RTA Specification. ......................................................................................................................... 1 Changes from Original (January 2011) to Revision A • 2 Page Updated Input-output Offset Voltage vs Pullup Resistor graphic. .......................................................................................... 6 Submit Documentation Feedback Copyright © 2011–2018, Texas Instruments Incorporated Product Folder Links: TCA4311A TCA4311A www.ti.com SCPS226C – JANUARY 2011 – REVISED AUGUST 2018 5 Pin Configuration and Functions D OR DGK Packages (Top View) Pin Functions PIN NAME DESCRIPTION NUMBER EN 1 Active-high chip enable pin. If EN is low, the TCA4311A is in a low current (