SLASF60 april   2023 DAC53204-Q1 , DAC63204-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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: Voltage Output
    6. 6.6  Electrical Characteristics: Current Output
    7. 6.7  Electrical Characteristics: Comparator Mode
    8. 6.8  Electrical Characteristics: General
    9. 6.9  Timing Requirements: I2C Standard Mode
    10. 6.10 Timing Requirements: I2C Fast Mode
    11. 6.11 Timing Requirements: I2C Fast Mode Plus
    12. 6.12 Timing Requirements: SPI Write Operation
    13. 6.13 Timing Requirements: SPI Read and Daisy Chain Operation (FSDO = 0)
    14. 6.14 Timing Requirements: SPI Read and Daisy Chain Operation (FSDO = 1)
    15. 6.15 Timing Requirements: GPIO
    16. 6.16 Timing Diagrams
    17. 6.17 Typical Characteristics: Voltage Output
    18. 6.18 Typical Characteristics: Current Output
    19. 6.19 Typical Characteristics: Comparator
    20. 6.20 Typical Characteristics: General
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Smart Digital-to-Analog Converter (DAC) Architecture
      2. 7.3.2 Digital Input/Output
      3. 7.3.3 Nonvolatile Memory (NVM)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Voltage-Output Mode
        1. 7.4.1.1 Voltage Reference and DAC Transfer Function
          1. 7.4.1.1.1 Internal Reference
          2. 7.4.1.1.2 External Reference
          3. 7.4.1.1.3 Power-Supply as Reference
      2. 7.4.2 Current-Output Mode
      3. 7.4.3 Comparator Mode
        1. 7.4.3.1 Programmable Hysteresis Comparator
        2. 7.4.3.2 Programmable Window Comparator
      4. 7.4.4 Fault-Dump Mode
      5. 7.4.5 Application-Specific Modes
        1. 7.4.5.1 Voltage Margining and Scaling
          1. 7.4.5.1.1 High-Impedance Output and PROTECT Input
          2. 7.4.5.1.2 Programmable Slew-Rate Control
          3. 7.4.5.1.3 PMBus Compatibility Mode
        2. 7.4.5.2 Function Generation
          1. 7.4.5.2.1 Triangular Waveform Generation
          2. 7.4.5.2.2 Sawtooth Waveform Generation
          3. 7.4.5.2.3 Sine Waveform Generation
      6. 7.4.6 Device Reset and Fault Management
        1. 7.4.6.1 Power-On Reset (POR)
        2. 7.4.6.2 External Reset
        3. 7.4.6.3 Register-Map Lock
        4. 7.4.6.4 NVM Cyclic Redundancy Check (CRC)
          1. 7.4.6.4.1 NVM-CRC-FAIL-USER Bit
          2. 7.4.6.4.2 NVM-CRC-FAIL-INT Bit
      7. 7.4.7 Power-Down Mode
    5. 7.5 Programming
      1. 7.5.1 SPI Programming Mode
      2. 7.5.2 I2C Programming Mode
        1. 7.5.2.1 F/S Mode Protocol
        2. 7.5.2.2 I2C Update Sequence
          1. 7.5.2.2.1 Address Byte
          2. 7.5.2.2.2 Command Byte
        3. 7.5.2.3 I2C Read Sequence
      3. 7.5.3 General-Purpose Input/Output (GPIO) Modes
    6. 7.6 Register Map
      1. 7.6.1  NOP Register (address = 00h) [reset = 0000h]
      2. 7.6.2  DAC-X-MARGIN-HIGH Register (address = 01h, 07h, 0Dh, 13h) [reset = 0000h]
      3. 7.6.3  DAC-X-MARGIN-LOW Register (address = 02h, 08h, 0Eh, 14h) [reset = 0000h]
      4. 7.6.4  DAC-X-VOUT-CMP-CONFIG Register (address = 03h, 09h, 0Fh, 15h) [reset = 0000h]
      5. 7.6.5  DAC-X-IOUT-MISC-CONFIG Register (address = 04h, 0Ah, 10h, 16h) [reset = 0000h]
      6. 7.6.6  DAC-X-CMP-MODE-CONFIG Register (address = 05h, 0Bh, 11h, 17h) [reset = 0000h]
      7. 7.6.7  DAC-X-FUNC-CONFIG Register (address = 06h, 0Ch, 12h, 18h) [reset = 0000h]
      8. 7.6.8  DAC-X-DATA Register (address = 19h, 1Ah, 1Bh, 1Ch) [reset = 0000h]
      9. 7.6.9  COMMON-CONFIG Register (address = 1Fh) [reset = 0FFFh]
      10. 7.6.10 COMMON-TRIGGER Register (address = 20h) [reset = 0000h]
      11. 7.6.11 COMMON-DAC-TRIG Register (address = 21h) [reset = 0000h]
      12. 7.6.12 GENERAL-STATUS Register (address = 22h) [reset = 00h, DEVICE-ID, VERSION-ID]
      13. 7.6.13 CMP-STATUS Register (address = 23h) [reset = 0000h]
      14. 7.6.14 GPIO-CONFIG Register (address = 24h) [reset = 0000h]
      15. 7.6.15 DEVICE-MODE-CONFIG Register (address = 25h) [reset = 0000h]
      16. 7.6.16 INTERFACE-CONFIG Register (address = 26h) [reset = 0000h]
      17. 7.6.17 SRAM-CONFIG Register (address = 2Bh) [reset = 0000h]
      18. 7.6.18 SRAM-DATA Register (address = 2Ch) [reset = 0000h]
      19. 7.6.19 DAC-X-DATA-8BIT Register (address = 40h, 41h, 42h, 43h) [reset = 0000h]
      20. 7.6.20 BRDCAST-DATA Register (address = 50h) [reset = 0000h]
      21. 7.6.21 PMBUS-PAGE Register [reset = 0300h]
      22. 7.6.22 PMBUS-OP-CMD-X Register [reset = 0000h]
      23. 7.6.23 PMBUS-CML Register [reset = 0000h]
      24. 7.6.24 PMBUS-VERSION Register [reset = 2200h]
  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
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  9. 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
  10. 10Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.2 Detailed Design Procedure

The DACx3204‑Q1 feature a Hi-Z power-down mode that is set at power-up by default, unless the device is programmed otherwise using the NVM. When the DAC output is at Hi-Z, the current through R3 is zero and the DC/DC converter is set at the nominal output voltage of 45 V. To have the same nominal condition when the DAC powers up, bring up the device at the same output voltage (1.2 V) as the DC/DC converter feedback pin (FB). This configuration makes sure there is no current through R3 even at power up. Calculate R1 as (VOUT – VFB) / 100 µA = 438 kΩ.

To achieve ±10% margin-high and margin-low conditions, the DAC must sink or source additional current through R1. Calculate the current from the DAC (IMARGIN) using Equation 9:

Equation 9. I M A R G I N = V O U T × ( 1 ± M A R G I N ) - V F B R 1 - I N O M I N A L

With a nominal VOUT of 45 V, margin of ±10%, VFB of 1.2 V, INOMINAL of 100 μA, and R1 of 438 kΩ, Equation 9 becomes Equation 10:

Equation 10. I M A R G I N = 45   V × ( 1 ± 0.1 ) - 1.2   V 438   k Ω   - 100   μ A = ± 10.27   μ A

To calculate the value of R3, first decide the DAC output range, and make sure to avoid the codes near zero-scale and full-scale for safe operation in the linear region. If 686 mV is chosen as the minimum output, the value for R3 is calculated by Equation 11:

Equation 11. R 3 = V D A C - V F B I M A R G I N = 686   m V - 1.2   V 10.27   μ A = 50   k Ω

Using the value of R3 the maximum DAC output is calculated to be 1.71 V.

When the DACx3204‑Q1 are set in the current-output mode, series resistor R3 is not required. Set the DAC output at the current-output range of –25 µA to +25 µA, and set the DAC code appropriately to achieve a margin current of ±10.7 µA.

The DACx3204‑Q1 have a slew-rate feature that is used to toggle between margin high, margin low, and nominal outputs with a defined slew rate. See Section 7.4.5.1.2 for the slew-rate setting details. This application example uses a SLEW_RATE of 4 µV/s and a CODE_STEP of 8 LSB to achieve a 1.17-ms slew time.

Note: The DAC-X-MARGIN-HIGH register value in DACx3204‑Q1 results in the margin-low value at the power supply output. Similarly, the DAC-X-MARGIN-LOW register value in DACx3204‑Q1 results in the margin-high value at the power-supply output.

The pseudocode for this application example is as follows: 

//SYNTAX: WRITE <REGISTER NAME (Hex code)>, <MSB DATA>, <LSB DATA>
//Write DAC code for nominal output (repeat for all DAC channels)
//For a 1.8-V output range, the 12-bit hex code for 1.2 V is 0xAAB. With 16-bit left alignment,
this becomes 0xAAB0
WRITE DAC_DATA(0x19), 0xAA, 0xB0
//Set gain setting to 1.5x internal reference (1.8 V) (repeat for all channels)
WRITE DAC-0-VOUT-CMP-CONFIG(0x3), 0x08, 0x00
//Power-up voltage output on all channels and enable the internal reference 
WRITE COMMON-CONFIG(0x1F),0x12, 0x49
//Configure GPI for Margin-High, Low trigger for all channels
WRITE GPIO-CONFIG(0x24), 0x01, 0xF5
//Set slew rate and code step (repeat for all channels)
//CODE_STEP: 8 LSB, SLEW_RATE: 4 µs/step
WRITE DAC-0-FUNC-CONFIG(0x06), 0x00, 0x51
//Write DAC margin high code (repeat for all channels)
//For a 1.8-V output range, the 12-bit hex code for 1.71 V is 0xF3C. With 16-bit left alignment,
this becomes 0xF3C0
WRITE DAC-0-MARGIN-HIGH(0x01), 0xF3, 0xC0
//Write DAC margin low code (repeat for all channels)
//For a 1.8-V output range, the 12-bit hex code for 686 mV is 0x61A. With 16-bit left alignment, this
becomes 0x61A0
WRITE DAC-0-MARGIN-LOW(0x02), 0x61, 0xA0
//Save settings to NVM
WRITE COMMON-TRIGGER(0x20), 0x00, 0x02