JAJSHB3G September   2011  – May 2019 TXB0304

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      TXB0304 の代表的なアプリケーション・ブロック図
  4. 4 改訂履歴
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 Operating Characteristics
    9. 6.9 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1 Architecture
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input Driver Requirements
    4. 8.4 Device Functional Modes
      1. 8.4.1 Enable and Disable
      2. 8.4.2 Pullup or Pulldown Resistor on I/O Lines
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 デバイス・サポート
      1. 12.1.1 開発サポート
    2. 12.2 ドキュメントのサポート
      1. 12.2.1 関連資料
    3. 12.3 コミュニティ・リソース
    4. 12.4 商標
    5. 12.5 静電気放電に関する注意事項
    6. 12.6 Glossary
  13. 13メカニカル、パッケージ、および注文情報

8.4.2 Pullup or Pulldown Resistor on I/O Lines

The TXB0304/TXBN0304 is designed to drive capacitive loads of up to 100 pF. The output drivers of the TXB0304 have low dc drive strength. If pull-up or pull-down resistors are connected externally to the data I/Os, their values must be kept higher than 20 kΩ to ensure that they do not contend with the output drivers of the TXB0304. but if the receiver is integrated with the smaller pull down or pull up resistor, below formula can be used for estimation to evaluate the VOH and VOL .

Equation 1. TXB0304 eq1_io_ces837.gif
Equation 2. TXB0304 eq2_io_ces837.gif

where

  • VCCOUT is the output port supply voltage on either VCCA or VCCB
  • RPD is the value of the external pull down resistor
  • RPU is the value of the external pull up resistor
  • 1.5 kΩ is the counting the variation of the serial resistor 1kΩ in the I/O line.

Because of this restriction on external resistors, the TXB0304 should not be used in applications such as I2C or 1-Wire where an open-drain driver is connected on the bidirectional data I/O. For these applications, use a device from the TI TXS010X series of level translators.