JAJSTM8 April   2024 AFE20408

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Switching Characteristics
    8. 5.8 Timing Diagrams
    9. 5.9 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Digital-to-Analog Converter (DAC) Overview
        1. 6.3.1.1 DAC Resistor String
        2. 6.3.1.2 DAC Register Structure
          1. 6.3.1.2.1 DAC Synchronous Operation
        3. 6.3.1.3 DAC Buffer Amplifier
          1. 6.3.1.3.1 Autorange Detection
          2. 6.3.1.3.2 Power-Supply Monitoring
      2. 6.3.2 Analog-to-Digital Converter (ADC)
        1. 6.3.2.1 Versatile High-Voltage Measurement Capability
        2. 6.3.2.2 High-Precision Delta-Sigma ADC
          1. 6.3.2.2.1 ADC Custom Channel Sequencer
        3. 6.3.2.3 Low Latency Digital Filter
        4. 6.3.2.4 Flexible Conversion Times and Averaging
        5. 6.3.2.5 Integrated Precision Oscillator
      3. 6.3.3 Output Switch Overview
      4. 6.3.4 Drain Switch Control
      5. 6.3.5 FLEXIO Pin
      6. 6.3.6 Internal Temperature Sensor
      7. 6.3.7 Programmable Out-of-Range Alarms
        1. 6.3.7.1 Temperature Sensor Alarm Function
        2. 6.3.7.2 Supply Out-of-Range Alarm Function
        3. 6.3.7.3 ADC Alarm Function
    4. 6.4 Device Functional Modes
      1. 6.4.1 All-Positive DAC Range Mode
      2. 6.4.2 All-Negative DAC Range Mode
      3. 6.4.3 Mixed DAC Range Mode
    5. 6.5 Programming
      1. 6.5.1 I2C Serial Interface
        1. 6.5.1.1 I2C Bus Overview
        2. 6.5.1.2 I2C Bus Definitions
        3. 6.5.1.3 I2C Target Address Selection
        4. 6.5.1.4 I2C Read and Write Operations
        5. 6.5.1.5 I2C Timeout Function
        6. 6.5.1.6 I2C General-Call Reset
      2. 6.5.2 Serial Peripheral Interface (SPI)
        1. 6.5.2.1 SPI Bus Overview
  8. 7 Register Maps
    1. 7.1 Global Register Map
      1. 7.1.1 Global Registers: Global Page
        1. 7.1.1.1  NOP_RESET Register (address = 00h) [reset = 0000h]
        2. 7.1.1.2  PAGE Register (address = 01h) [reset = 0000h]
        3. 7.1.1.3  GEN_STATUS Register (address = 03h) [reset = 4000h]
        4. 7.1.1.4  ALARM_STATUS_0 Register (address = 04h) [reset = 0000h]
        5. 7.1.1.5  ALARM_STATUS_1 Register (address = 05h) [reset = 0000h]
        6. 7.1.1.6  PWR_STATUS_0 Register (address = 06h) [reset = 0001h]
        7. 7.1.1.7  PWR_STATUS_1 Register (address = 07h) [reset = 0000h]
        8. 7.1.1.8  PWR_EN Register (address = 08h) [reset = 0200h]
        9. 7.1.1.9  TRIGGER Register (address = 10h) [reset = 0000h]
        10. 7.1.1.10 GPIO_DATA Register (address = 11h) [reset = 0001h]
        11. 7.1.1.11 DRVEN_SW_EN Register (address = 12h) [reset = 00FFh]
        12. 7.1.1.12 DRVEN Register (address = 13h) [reset = 0000h]
        13. 7.1.1.13 DAC_BCAST Register (address = 14h) [reset = 0000h]
        14. 7.1.1.14 GLOBAL_CFG Register (address = 17h) [reset = 0000h]
        15. 7.1.1.15 ADC_SENSE0 Register (address = 18h) [reset = 0000h]
        16. 7.1.1.16 ADC_SENSE1 Register (address = 19h) [reset = 0000h]
        17. 7.1.1.17 ADC_ADC0 Register (address = 1Ah) [reset = 0000h]
        18. 7.1.1.18 ADC_ADC1 Register (address = 1Bh) [reset = 0000h]
        19. 7.1.1.19 ADC_TMP Register (address = 1Ch) [reset = 0000h]
    2. 7.2 General Configuration Register Map
      1. 7.2.1 General Configuration Registers: Page 0
        1. 7.2.1.1  CHIP_ID Register (address = 40h) [reset = 2480h]
        2. 7.2.1.2  CHIP_VER Register (address = 41h) [reset = 0000h]
        3. 7.2.1.3  SDO_EN Register (address = 42h) [reset = 0000h]
        4. 7.2.1.4  GEN_CFG_0 Register (address = 44h) [reset = 0010h]
        5. 7.2.1.5  GEN_CFG_1 Register (address = 45h) [reset = 1101h]
        6. 7.2.1.6  ALARMOUT_SRC_0 Register (address = 48h) [reset = 0000h]
        7. 7.2.1.7  ALARMOUT_SRC_1 Register (address = 49h) [reset = 1833h]
        8. 7.2.1.8  ALARM_STATUS_0_BYP Register (address = 4Ch) [reset = 0000h]
        9. 7.2.1.9  ALARM_STATUS_1_BYP Register (address = 4Dh) [reset = 0000h]
        10. 7.2.1.10 PAON_SRC_0 Register (address = 50h) [reset = 0000h]
        11. 7.2.1.11 PAON_SRC_1 Register (address = 51h) [reset = 1833h]
        12. 7.2.1.12 RESET_FLAGS Register (Offset = 70h) [Reset = 000Fh]
    3. 7.3 ADC Configuration Register Map
      1. 7.3.1 ADC Configuration Registers: Page 1
        1. 7.3.1.1  ADC_GEN_CFG Register (address = 40h) [reset = 3334h]
        2. 7.3.1.2  ADC_CONV_CFG_0 Register (address = 41h) [reset = 0555h]
        3. 7.3.1.3  ADC_CONV_CFG_1 Register (address = 42h) [reset = 0000h]
        4. 7.3.1.4  ADC_BYP Register (address = 44h) [reset = 0000h]
        5. 7.3.1.5  ADC_HYST_0 Register (address = 46h) [reset = 0808h]
        6. 7.3.1.6  ADC_HYST_1 Register (address = 47h) [reset = 0008h]
        7. 7.3.1.7  SENSE0_UP_THRESH Register (address = 50h) [reset = 7FFFh]
        8. 7.3.1.8  SENSE0_LO_THRESH Register (address = 51h) [reset = 8000h]
        9. 7.3.1.9  SENSE1_UP_THRESH Register (address = 52h) [reset = 7FFFh]
        10. 7.3.1.10 SENSE1_LO_THRESH Register (address = 53h) [reset = 8000h]
        11. 7.3.1.11 ADC0_UP_THRESH Register (address = 54h) [reset = 7FFFh]
        12. 7.3.1.12 ADC0_LO_THRESH Register (address = 55h) [reset = 0000h]
        13. 7.3.1.13 ADC1_UP_THRESH Register (address = 56h) [reset = 7FFFh]
        14. 7.3.1.14 ADC1_LO_THRESH Register (address = 57h) [reset = 0000h]
        15. 7.3.1.15 TMP_UP_THRESH Register (address = 58h) [reset = 7FFFh]
    4. 7.4 ADC Custom Channel Sequencer Configuration Register Map
      1. 7.4.1 ADC CCS Registers: Page 3
        1. 7.4.1.1 ADC_CCS_IDS_n Registers (address = 40h to 7Eh) [reset = see ]
        2. 7.4.1.2 ADC_CCS_CFG_0 Register (address = 7Fh) [reset = 0004h]
    5. 7.5 DAC Configuration Register Map
      1. 7.5.1 DAC Configuration Registers: Page 3
        1. 7.5.1.1  DAC_CURRENT Register (address = 40h) [reset = 0000h]
        2. 7.5.1.2  DAC_SYNC_CFG Register (address = 41h) [reset = 0000h]
        3. 7.5.1.3  DAC_CFG Register (address = 42h) [reset = 0000h]
        4. 7.5.1.4  DAC_APD_EN Register (address = 43h) [reset = AAFFh]
        5. 7.5.1.5  DACA_APD_SRC_0 Register (address = 44h) [reset = 0000h]
        6. 7.5.1.6  DACA_APD_SRC_1 Register (address = 45h) [reset = 1833h]
        7. 7.5.1.7  OUTA_APD_SRC_0 Register (address = 46h) [reset = 0000h]
        8. 7.5.1.8  OUTA_APD_SRC_1 Register (address = 47h) [reset = 1833h]
        9. 7.5.1.9  DACB_APD_SRC_0 Register (address = 48h) [reset = 0000h]
        10. 7.5.1.10 DACB_APD_SRC_1 Register (address = 49h) [reset = 1833h]
        11. 7.5.1.11 OUTB_APD_SRC_0 Register (address = 4Ah) [reset = 0000h]
        12. 7.5.1.12 OUTB_APD_SRC_1 Register (address = 4Bh) [reset = 1833h]
        13. 7.5.1.13 DAC_CODE_LIMIT_0 Register (address = 4Ch) [reset = 3F3Fh]
        14. 7.5.1.14 DAC_CODE_LIMIT_1 Register (address = 4Dh) [reset = 3F3Fh]
        15. 7.5.1.15 DAC_CODE_LIMIT_2 Register (address = 4Eh) [reset = 3F3Fh]
        16. 7.5.1.16 DAC_CODE_LIMIT_3 Register (address = 4Fh) [reset = 3F3Fh]
        17. 7.5.1.17 DRVEN0_EN Register (address = 50h) [reset = 0000h]
        18. 7.5.1.18 DRVEN1_EN Register (address = 51h) [reset = 0000h]
        19. 7.5.1.19 FLEXIO_EN Register (address = 52h) [reset = 0000h]
    6. 7.6 DAC Buffer Register Map
      1. 7.6.1 DAC Buffer Data Registers: Page 4
        1. 7.6.1.1 DACA/Bn Buffer Registers (address = 40h to 47h) [reset = 0000h]
    7. 7.7 DAC Active Register Map
      1. 7.7.1 DAC Active Data Registers: Page 4
        1. 7.7.1.1 DACA/Bn Active Register (address = 40h to 47h) [reset = 0000h]
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Output Switching Timing
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 ADC Input Conditioning
        2. 8.2.2.2 Quiescent Current and Total Power Consumption
          1. 8.2.2.2.1 Maximum VCC/VSS Supply Current Transients
          2. 8.2.2.2.2 DAC Load Stability
        3. 8.2.2.3 Disabling PA Drain Voltage
        4. 8.2.2.4 PAON External Circuit
      3. 8.2.3 Application Curves
        1. 8.2.3.1 DAC Load Stability
        2. 8.2.3.2 Start-Up Behavior
    3. 8.3 Initialization Setup
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Diagram
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 ドキュメントの更新通知を受け取る方法
    3. 9.3 サポート・リソース
    4. 9.4 Trademarks
    5. 9.5 静電気放電に関する注意事項
    6. 9.6 用語集
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

6.3.4 Drain Switch Control

The AFE20408 device includes an output-control voltage (PAON pin) capable of driving an external MOSFET switch that turns on and off the drain current to a PA FET. The use of this control signal in conjunction with the DAC clamp option allows control of the sequence in which the PA FET is powered up and powered down.

The PAON pin is disabled on start-up. After the device powers on, the PAON pin can be enabled by setting the PAON bit to 1, in the PWR_EN register (located in the global register page). During operation, the status of the PAON pin can be monitored by reading the PAON_STS bit in the GEN_STATUS register (located in the global register page). By default, the PAON pin is pulled to GND, and is in the OFF state.

The maximum output voltage is determined by the voltage at the VDD pin. When enabled, the PAON can be turned off by any alarm generated by the various monitoring circuits in the device, including thermal, supply, ADC, and reference alarms. This configuration is done by writing to the appropriate bits in the PAON_SRC_0 and PAON_SRC_1 registers (located in the general configuration register page).

AFE20408 PAON Operation Figure 6-9 PAON Operation

The PAON pin operates in push-pull mode by default. The PAON pin can be configured to operate in open-drain mode by setting the PAON_ODE bit in the GEN_CFG_0 register (located in the general configuration register page). In push-pull mode, the PAON pin is internally connected to VDD via a pullup resistor. As a result, the PAON pin outputs 0V (or the voltage at GND) while in the OFF state, and VDD while in the ON state. In the open drain mode, there is no internal pullup resistor to the VDD pin, and the user must install an external pullup resistor to VDD. This is further described in Section 8.2.2.4.

Additionally, the PAON pin can be configured to invert the ON and OFF states (so that the high voltage is off and the low voltage is on) by setting the PAON_POL bit in the GEN_CFG_0 register (located in the general configuration register page).

For FETs requiring a negative bias voltage, such as GaN, making sure that the bias voltage remains within an acceptable range is crucial; otherwise, significant and irreversible damage to the FET can occur. The AFE20408 bipolar DAC operation and clamping mechanism rely on the VDD and VSS voltages for proper operation. For this reason, when either the VDD or VSS voltage falls outside the acceptable range, turning off the drain current to the FET is desirable.