JAJSH97A April   2019  – September 2019 TPS3840-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
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements
    7. 8.7 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Input Voltage (VDD)
        1. 9.3.1.1 VDD Hysteresis
        2. 9.3.1.2 VDD Transient Immunity
      2. 9.3.2 User-Programmable Reset Time Delay
      3. 9.3.3 Manual Reset (MR) Input
      4. 9.3.4 Output Logic
        1. 9.3.4.1 RESET Output, Active-Low
        2. 9.3.4.2 RESET Output, Active-High
    4. 9.4 Device Functional Modes
      1. 9.4.1 Normal Operation (VDD > VDD(min))
      2. 9.4.2 VDD Between VPOR and VDD(min)
      3. 9.4.3 Below Power-On-Reset (VDD < VPOR)
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design 1: Dual Rail Monitoring with Power-Up Sequencing
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
        3. 10.2.1.3 Application Curves
      2. 10.2.2 Design 2: Automotive Off-Battery Monitoring
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
        3. 10.2.2.3 Application Curves: TPS3840EVM
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13デバイスおよびドキュメントのサポート
    1. 13.1 デバイスの項目表記
    2. 13.2 コミュニティ・リソース
    3. 13.3 商標
    4. 13.4 静電気放電に関する注意事項
    5. 13.5 Glossary
  14. 14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

10.2.2.1 Design Requirements

This design requires voltage supervision on a 12-V power supply voltage rail with possibility of the 12-V rail rising up as high as 42 V. The undervoltage fault occurs when the power supply voltage drops below 7.7 V.

PARAMETER DESIGN REQUIREMENT DESIGN RESULT
Power Rail Voltage Supervision Monitor 12-V power supply for undervoltage condition, trigger a undervoltage fault at 7.7 V. TPS3840-Q1 provides voltage monitoring with 1% accuracy with device options available in 0.1 V variations. Resistor dividers are calculated based on device variant and desired threshold voltage.
Maximum Input Power Operate with power supply input up to 42 V. The TPS3840-Q1 limits VDD to 10 V but can monitor voltages higher than the maximum VDD voltage with the use of an external resistor divider.
Output logic voltage Open-Drain Output Topology Due to large variance in battery voltage, an open-drain output is recommended to provide the correct reset signal.
Maximum system current consumption 35 uA when power supply is at 12 V typical TPS3840-Q1 requires 350 nA (typical) and the external resistor divider will also consume current. There is a tradeoff between current consumption and voltage monitor accuracy but generally set the resistor divider to consume 100 times current into VDD.
Voltage Monitor Accuracy Typical voltage monitor accuracy of 2.5%. The TPS3840-Q1 has 1% typical voltage monitor accuracy. By decreasing the ratio of resistor values, the resistor divider will consume more current but the accuracy will increase. The resistor tolerance also needs to be accounted for.
Delay when returning from fault condition RESET delay of at least 200 ms when returning from a undervoltage fault. CCT = 0.33 µF sets 204 ms delay