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TCA9517A

ACTIVE

2-bit level-translating 400-kHz I2C/SMBus buffer/repeater with powered-off high-impedance

Product details

Features Buffer, Enable pin Protocols I2C Frequency (max) (MHz) 0.4 VCCA (min) (V) 0.9 VCCA (max) (V) 5.5 VCCB (min) (V) 2.7 VCCB (max) (V) 5.5 Supply restrictions VCCA <= VCCB Rating Catalog Operating temperature range (°C) -40 to 85
Features Buffer, Enable pin Protocols I2C Frequency (max) (MHz) 0.4 VCCA (min) (V) 0.9 VCCA (max) (V) 5.5 VCCB (min) (V) 2.7 VCCB (max) (V) 5.5 Supply restrictions VCCA <= VCCB Rating Catalog Operating temperature range (°C) -40 to 85
VSSOP (DGK) 8 14.7 mm² 3 x 4.9
  • Two-Channel Bidirectional Buffer
  • I2C Bus and SMBus Compatible
  • Operating Supply Voltage Range of 0.9V to 5.5V on A-side
  • Operating Supply Voltage Range of 2.7V to 5.5V on B-side
  • Voltage-Level Translation From 0.9V - 5.5V to 2.7V - 5.5V
  • Footprint and Functional Replacement for PCA9515B
  • Active-High Repeater-Enable Input
  • Open-Drain I2C I/O
  • 5.5V Tolerant I2C and Enable Input Support Mixed-Mode Signal Operation
  • Accommodates Standard Mode and Fast Mode I2C Devices and Multiple Masters
  • High-Impedance I2C Pins When Powered-Off
  • Latch-Up Performance Exceeds 100mA Per JESD 78, Class II
  • ESD Protection Exceeds JESD 22
    • 5500V Human-Body Model (A114-A)
    • 200V Machine Model (A115-A)
    • 1000V Charged-Device Model (C101)
  • Two-Channel Bidirectional Buffer
  • I2C Bus and SMBus Compatible
  • Operating Supply Voltage Range of 0.9V to 5.5V on A-side
  • Operating Supply Voltage Range of 2.7V to 5.5V on B-side
  • Voltage-Level Translation From 0.9V - 5.5V to 2.7V - 5.5V
  • Footprint and Functional Replacement for PCA9515B
  • Active-High Repeater-Enable Input
  • Open-Drain I2C I/O
  • 5.5V Tolerant I2C and Enable Input Support Mixed-Mode Signal Operation
  • Accommodates Standard Mode and Fast Mode I2C Devices and Multiple Masters
  • High-Impedance I2C Pins When Powered-Off
  • Latch-Up Performance Exceeds 100mA Per JESD 78, Class II
  • ESD Protection Exceeds JESD 22
    • 5500V Human-Body Model (A114-A)
    • 200V Machine Model (A115-A)
    • 1000V Charged-Device Model (C101)

The TCA9517A is a bidirectional buffer with level shifting capabilities for I2C and SMBus systems. It provides bidirectional voltage-level translation (up-translation/down-translation) between low voltages (down to 0.9V) and higher voltages (2.7V to 5.5V) in mixed-mode applications. This device enables I2C and SMBus systems to be extended without degradation of performance, even during level shifting.

The TCA9517A buffers both the serial data (SDA) and the serial clock (SCL) signals on the I2C bus, thus allowing two buses of up to 400pF bus capacitance to be connected in an I2C application.

The TCA9517A has two types of drivers: A-side drivers and B-side drivers. All inputs and I/Os are over-voltage tolerant to 5.5V, even when the device is unpowered (VCCB and/or VCCA = 0V).

The TCA9517A offers a higher contention level threshold, VILC, than the TCA9517, which allows connections to slaves which have weaker pulldown ability.

The type of buffer design on the B-side prevents it from being used in series with devices which use static voltage offset. This is because these devices do not recognize buffered low signals as a valid low and do not propagate it as a buffered low again.

The B-side drivers operate from 2.7 V to 5.5 V. The output low level for this internal buffer is approximately 0.5 V, but the input voltage must be 70 mV or more below the output low level when the output internally is driven low. The higher-voltage low signal is called a buffered low. When the B-side I/O is driven low internally, the low is not recognized as a low by the input. This feature prevents a lockup condition from occurring when the input low condition is released.

The TCA9517A is a bidirectional buffer with level shifting capabilities for I2C and SMBus systems. It provides bidirectional voltage-level translation (up-translation/down-translation) between low voltages (down to 0.9V) and higher voltages (2.7V to 5.5V) in mixed-mode applications. This device enables I2C and SMBus systems to be extended without degradation of performance, even during level shifting.

The TCA9517A buffers both the serial data (SDA) and the serial clock (SCL) signals on the I2C bus, thus allowing two buses of up to 400pF bus capacitance to be connected in an I2C application.

The TCA9517A has two types of drivers: A-side drivers and B-side drivers. All inputs and I/Os are over-voltage tolerant to 5.5V, even when the device is unpowered (VCCB and/or VCCA = 0V).

The TCA9517A offers a higher contention level threshold, VILC, than the TCA9517, which allows connections to slaves which have weaker pulldown ability.

The type of buffer design on the B-side prevents it from being used in series with devices which use static voltage offset. This is because these devices do not recognize buffered low signals as a valid low and do not propagate it as a buffered low again.

The B-side drivers operate from 2.7 V to 5.5 V. The output low level for this internal buffer is approximately 0.5 V, but the input voltage must be 70 mV or more below the output low level when the output internally is driven low. The higher-voltage low signal is called a buffered low. When the B-side I/O is driven low internally, the low is not recognized as a low by the input. This feature prevents a lockup condition from occurring when the input low condition is released.

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Technical documentation

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Type Title Date
* Data sheet TCA9517A Level-Shifting I2 C Bus Repeater datasheet (Rev. D) PDF | HTML 05 Sep 2024
Application note Understanding Transient Drive Strength vs. DC Drive Strength in Level-Shifters (Rev. A) PDF | HTML 03 Jul 2024
Application note Resolving Improper Implementation of the Static Voltage Offset on I2C Buffers PDF | HTML 09 Oct 2023
Application note Why, When, and How to use I2C Buffers 23 May 2018
Application note Choosing the Correct I2C Device for New Designs PDF | HTML 07 Sep 2016
Application note Understanding the I2C Bus PDF | HTML 30 Jun 2015
Application note Maximum Clock Frequency of I2C Bus Using Repeaters 15 May 2015
Application note I2C Bus Pull-Up Resistor Calculation PDF | HTML 13 Feb 2015

Design & development

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Simulation model

TCA9517A IBIS Model

SCPM026.ZIP (46 KB) - IBIS Model
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