JAJSIR7C October   2019  – August 2021 TPS8804

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  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 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 System Power-up
      2. 7.3.2 LDO Regulators
        1. 7.3.2.1 Power LDO Regulator
        2. 7.3.2.2 Internal LDO Regulator
        3. 7.3.2.3 Microcontroller LDO Regulator
      3. 7.3.3 Photo Chamber AFE
        1. 7.3.3.1 Photo Input Amplifier
        2. 7.3.3.2 Photo Gain Amplifier
      4. 7.3.4 LED Driver
        1. 7.3.4.1 LED Current Sink
        2. 7.3.4.2 LED Voltage Supply
      5. 7.3.5 Carbon Monoxide Sensor AFE
        1. 7.3.5.1 CO Transimpedance Amplifier
        2. 7.3.5.2 CO Connectivity Test
      6. 7.3.6 SLC Interface Transmitter and Receiver
        1. 7.3.6.1 SLC Transmitter
        2. 7.3.6.2 SLC Receiver
      7. 7.3.7 AMUX
      8. 7.3.8 Analog Bias Block and 8 MHz Oscillator
      9. 7.3.9 Interrupt Signal Alerts
    4. 7.4 Device Functional Modes
      1. 7.4.1 Fault States
        1. 7.4.1.1 MCU LDO Fault
        2. 7.4.1.2 Over-Temperature Fault
    5. 7.5 Programming
    6. 7.6 Register Maps
      1. 7.6.1  REVID Register (Offset = 0h) [reset = 0h]
      2. 7.6.2  STATUS1 Register (Offset = 1h) [reset = 0h]
      3. 7.6.3  STATUS2 Register (Offset = 2h) [reset = 0h]
      4. 7.6.4  MASK Register (Offset = 3h) [reset = 0h]
      5. 7.6.5  CONFIG1 Register (Offset = 4h) [reset = 20h]
      6. 7.6.6  CONFIG2 Register (Offset = 5h) [reset = 0h]
      7. 7.6.7  ENABLE1 Register (Offset = 6h) [reset = 0h]
      8. 7.6.8  ENABLE2 Register (Offset = 7h) [reset = 0h]
      9. 7.6.9  CONTROL Register (Offset = 8h) [reset = 0h]
      10. 7.6.10 GPIO_AMUX Register (Offset = Bh) [reset = 0h]
      11. 7.6.11 COSW Register (Offset = Ch) [reset = 0h]
      12. 7.6.12 CO Register (Offset = Dh) [reset = 0h]
      13. 7.6.13 LEDLDO Register (Offset = Fh) [reset = 0h]
      14. 7.6.14 PH_CTRL Register (Offset = 10h) [reset = 0h]
      15. 7.6.15 LED_DAC_A Register (Offset = 11h) [reset = 0h]
      16. 7.6.16 LED_DAC_B Register (Offset = 12h) [reset = 0h]
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Photo Amplifier Component Selection
        2. 8.2.2.2 LED Driver Component Selection
        3. 8.2.2.3 LED Voltage Supply Selection
        4. 8.2.2.4 Regulator Component Selection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Photo Amplifier Layout
      2. 10.1.2 CO Amplifier Layout
      3. 10.1.3 Ground Plane Layout
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 ドキュメントの更新通知を受け取る方法
    2. 11.2 サポート・リソース
    3. 11.3 Trademarks
    4. 11.4 静電気放電に関する注意事項
    5. 11.5 用語集
  12. 12Mechanical, Packaging, and Orderable Information

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

7.3.5.1 CO Transimpedance Amplifier

The CO transimpedance amplifier is a low-offset, low-power op-amp with integrated input, gain, and output resistors. Each of these resistors can be disconnected using the COSW register bits if using external resistors. The input resistor limits amplifier current during a CO sensor connectivity test. The gain resistor amplifies the CO sensor signal. Adjust the gain resistor by changing the COGAIN register bits. Use the output resistor with an external capacitor to filter the CO amplifier output signal.

The CO amplifier has two integrated references. A programmable 1.25-mV to 5-mV reference COREF is internally connected to the op-amp positive terminal. A 300-mV reference is connected to the REF0P3 pin. When the millivolt reference is used, the CO sensor must be connected to GND. The millivolt reference is amplified to offset the amplifier output above GND. When the 300 mV reference is used, the reference offsets the CO amplifier output by 300 mV. In general, either reference can be used. The 300-mV reference offers better DC accuracy at the cost of extra power consumption. The 300 mV reference is generated with a reference and op-amp buffer for high precision. The REF0P3 pin must connect to a 1 nF capacitor for stability if it is enabled. The buffer is designed to source and sink small currents as required by the CO amplifier. The 300 mV reference and the 1.25 mV to 5mV reference cannot be enabled simultaneously.

A resistor connected in parallel with the CO sensor prevents charge from accumulating across its terminals. The output of the CO amplifier is connected to the COO pin for continuous monitoring and the AMUX for periodic sampling.