SLASF07 September   2023 DAC43901-Q1 , DAC43902-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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: Comparator Mode
    6. 6.6  Electrical Characteristics: General
    7. 6.7  Timing Requirements: I2C Standard Mode
    8. 6.8  Timing Requirements: I2C Fast Mode
    9. 6.9  Timing Requirements: I2C Fast-Mode Plus
    10. 6.10 Timing Requirements: SPI Write Operation
    11. 6.11 Timing Requirements: SPI Read and Daisy Chain Operation (FSDO = 0)
    12. 6.12 Timing Requirements: SPI Read and Daisy Chain Operation (FSDO = 1)
    13. 6.13 Timing Requirements: PWM Output
    14. 6.14 Timing Diagrams
    15. 6.15 Typical Characteristics
  8. 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 Threshold DAC
        1. 7.3.2.1 Voltage Reference and DAC Transfer Function
        2. 7.3.2.2 Power-Supply as Reference
        3. 7.3.2.3 Internal Reference
        4. 7.3.2.4 External Reference
      3. 7.3.3 Programming Interface
      4. 7.3.4 Nonvolatile Memory (NVM)
        1. 7.3.4.1 NVM Cyclic Redundancy Check (CRC)
          1. 7.3.4.1.1 NVM-CRC-FAIL-USER Bit
          2. 7.3.4.1.2 NVM-CRC-FAIL-INT Bit
      5. 7.3.5 Power-On Reset (POR)
      6. 7.3.6 External Reset
      7. 7.3.7 Register-Map Lock
    4. 7.4 Device Functional Modes
      1. 7.4.1 Comparator Mode
      2. 7.4.2 PWM Fade-In Fade-Out Mode
      3. 7.4.3 Sequential Turn-Indicator Animation 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
    6. 7.6 Register Maps
      1. 7.6.1  NOP Register (address = 00h) [reset = 0000h]
      2. 7.6.2  DAC-x-VOUT-CMP-CONFIG Register (address = 15h, 03h)
      3. 7.6.3  COMMON-CONFIG Register (address = 1Fh)
      4. 7.6.4  COMMON-TRIGGER Register (address = 20h) [reset = 0000h]
      5. 7.6.5  COMMON-PWM-TRIG Register (address = 21h) [reset = 0000h]
      6. 7.6.6  GENERAL-STATUS Register (address = 22h) [reset = 00h, DEVICE-ID, VERSION-ID]
      7. 7.6.7  INTERFACE-CONFIG Register (address = 26h) [reset = 0000h]
      8. 7.6.8  STATE-MACHINE-CONFIG0 Register (address = 27h) [reset = 0003h]
      9. 7.6.9  SRAM-CONFIG Register (address = 2Bh) [reset = 0000h]
      10. 7.6.10 SRAM-DATA Register (address = 2Ch) [reset = 0000h]
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Sequential Turn Indicator
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Logarithmic Fade-In Fade-Out
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.5.1 SPI Programming Mode

An SPI access cycle for DAC4390x-Q1 is initiated by asserting the SYNC pin low. The serial clock, SCLK, can be a continuous or gated clock. SDI data are clocked on SCLK falling edges. The SPI frame for DAC4390x-Q1 is 24 bits long. Therefore, the SYNC pin must stay low for at least 24 SCLK falling edges. The access cycle ends when the SYNC pin is deasserted high. If the access cycle contains less than the minimum clock edges, the communication is ignored. By default, the SDO pin is not enabled (three-wire SPI). In the three-wire SPI mode, if the access cycle contains more than the minimum clock edges, only the first 24 bits are used by the device. When SYNC is high, the SCLK and SDI signals are blocked, and SDO becomes Hi-Z to allow data readback from other devices connected on the bus.

Table 7-12 and Figure 7-11 describe the format for the 24-bit SPI access cycle. The first byte input to SDI is the instruction cycle. The instruction cycle identifies the request as a read or write command and the 7-bit address that is to be accessed. The last 16 bits in the cycle form the data cycle.

Table 7-12 SPI Read/Write Access Cycle
BIT FIELD DESCRIPTION
23 R/W Identifies the communication as a read or write command to the address register: R/W = 0 sets a write operation. R/W = 1 sets a read operation
22-16 A[6:0] Register address: specifies the register to be accessed during the read or write operation
15-0 DI[15:0] Data cycle bits: If a write command, the data cycle bits are the values to be written to the register with address A[6:0]. If a read command, the data cycle bits are don't care values.
GUID-20211103-SS0I-ZB6H-BKVT-XNZ92XCJMFCX-low.svg Figure 7-11 SPI Write Cycle

Read operations require that the SDO pin is first enabled by setting the SDO-EN bit in the INTERFACE-CONFIG register. This configuration is called four-wire SPI. A read operation is initiated by issuing a read command access cycle. After the read command, a second access cycle must be issued to get the requested data. The output data format is shown in Table 7-13 and Figure 7-12. Data are clocked out on the SDO pin either on the falling edge or rising edge of SCLK according to the FSDO bit (see Figure 6-3).

Table 7-13 SDO Output Access Cycle
BIT FIELD DESCRIPTION
23 R/W Echo R/W from previous access cycle
22-16 A[6:0] Echo register address from previous access cycle
15-0 DI[15:0] Readback data requested on previous access cycle
GUID-20211103-SS0I-NKQR-LWBD-4XT57M0LH4WV-low.svg Figure 7-12 SPI Read Cycle

The daisy-chain operation is also enabled with the SDO pin. In daisy-chain mode, multiple devices are connected in a chain with the SDO pin of one device is connected to SDI pin of the following device, as shown in Figure 7-13. The SPI host drives the SDI pin of the first device in the chain. The SDO pin of the last device in the chain is connected to the POCI pin of the SPI host. In four-wire SPI mode, if the access cycle contains multiples of 24 clock edges, only the last 24 bits are used by the device first device in the chain. If the access cycle contains clock edges that are not in multiples of 24, the SPI packet is ignored by the device. Figure 7-14 describes the packet format for the daisy-chain write cycle.

GUID-20211103-SS0I-T93Z-FXBN-QPWLXZXDD8WL-low.svg Figure 7-13 SPI Daisy-Chain Connection
GUID-20211103-SS0I-JJFL-PS2S-WG6LL7HSTRFZ-low.svg Figure 7-14 SPI Daisy-Chain Write Cycle