SLASF96 April   2024 AFE20408

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  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 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RHB|32
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6.3.7 Programmable Out-of-Range Alarms

The AFE20408 is capable of continuously analyzing the supplies, reference, external ADC inputs, and internal temperature for normal operation. Normal operation for the conversion results is established through the lower- and upper-threshold registers. When any of the monitored inputs is out of the specified range, the corresponding alarm bit in the alarm status registers is set. In addition, the global alarm bit (GALR in the GEN_STATUS register) is also set.

All of the alarms can be set to activate the FLEXIO pin, when configured as ALARMOUT. Any alarm event can activate the pin as long as the alarm is not masked in the ALARMOUT_SRC registers. When an alarm event is masked, the occurrence of the event sets the corresponding status bit in the alarm status registers, but does not activate the ALARMOUT pin.

The ALARM_LATCH_DIS bit (located in the GEN_CFG_0 register, part of the General Configuration register page) sets the latching behavior for the internal device alarms, as well as the ALARMOUT pin. When the ALARM_LATCH_DIS bit is cleared to 0, the alarms are latched. The alarms are referred to as being latched because the GALR bit and ALARMOUT pin remain active until the GEN_STATUS register is read by software, even if the alarm condition subsides before the read. This design makes sure that out-of-limit events cannot be missed if the software is polling the device periodically. When the ALARM_LATCH_DIS bit is set to 1, the alarm bits are not latched. In this case, the GALR bit and ALARMOUT pin are deactivated as soon as the error condition subsides, regardless of whether the GEN_STATUS register is read or not. Regardless of the ALARM_LATCH_DIS bit value, all bits in the alarm status registers are cleared only after a software read. Read the alarm status registers twice to confirm that the bits have cleared after the alarm condition subsides. These bits are reasserted if the out-of limit condition still exists on the next monitoring cycle.

In addition, all of the alarms can be set to force one or more DACs to the power-down state. To enable this functionality, the alarm event must be enabled as a power-down source by writing to the appropriate bits within the DAC_APD_SRC and OUT_APD_SRC registers (all located within the DAC Configuration register page). Additionally, the DAC outputs to be controlled by the alarm event must be specified. In this application, when a DAC control alarm event is detected, all the DACs that are set to power down in response to the alarm do so. When the alarm event is cleared, the DACs are reloaded with the contents of the DAC active registers, which allows the DAC outputs to return to the previous operating point without any additional commands.