JAJSCZ8B March   2017  – February 2018 TPS3890-Q1

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      代表的なアプリケーション回路
      2.      VITNの精度と温度との関係
  4. 4 改訂履歴
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 User-Configurable RESET Delay Time
      2. 8.3.2 Manual Reset (MR) Input
      3. 8.3.3 RESET Output
      4. 8.3.4 SENSE Input
        1. 8.3.4.1 Immunity to SENSE Pin Voltage Transients
    4. 8.4 Device Functional Modes
      1. 8.4.1 Normal Operation (VDD > VDD(min))
      2. 8.4.2 Above Power-On-Reset But Less Than VDD(min) (VPOR < VDD < VDD(min))
      3. 8.4.3 Below Power-On-Reset (VDD < VPOR)
  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 デバイスの項目表記
    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 ドキュメントの更新通知を受け取る方法
    4. 12.4 コミュニティ・リソース
    5. 12.5 商標
    6. 12.6 静電気放電に関する注意事項
    7. 12.7 Glossary
  13. 13メカニカル、パッケージ、および注文情報

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.2.2 Detailed Design Procedure

The primary constraint for this application is choosing the correct device to monitor the supply voltage of the microprocessor. The TPS389018-Q1 has a negative threshold of 1.73 V and a positive threshold of 1.74 V, making the device suitable for monitoring a 1.8-V rail. The secondary constraint for this application is the reset delay time that must be at least 1 ms to allow the Delfino microprocessor enough time to startup up correctly. Because a minimum time is required, the worst-case scenario is a supervisor with a high CT charging current (ICT) and a low CT comparator threshold (VCT). For applications with ambient temperatures ranging from –40°C to +125°C, CCT can be calculated using ICT(Max), VCT(MIN), and solving for CCT in Equation 1 such that the minimum capacitance required at the CT pin is 1.149 nF. If standard capacitors with ±20% tolerances are used, then the CT capacitor must be 1.5 nF or larger to ensure that the 1-ms delay time is met.

A 0.1-µF decoupling capacitor is connected to the VDD pin as a good analog design practice and a 1-MΩ resistor is used as the RESET pullup resistor to minimize the current consumption when RESET is asserted. The MR pin can be connected to an external signal if desired or connected to VDD if not used.