JAJSSA9 November   2023 DAC61401 , DAC81401

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: Write, IOVDD: 1.7 V to 2.7 V
    7. 5.7  Timing Requirements: Write, IOVDD: 2.7 V to 5.5 V
    8. 5.8  Timing Requirements: Read and Daisy Chain, FSDO = 0, IOVDD: 1.7 V to 2.7 V
    9. 5.9  Timing Requirements: Read and Daisy Chain, FSDO = 1, IOVDD: 1.7 V to 2.7 V
    10. 5.10 Timing Requirements: Read and Daisy Chain, FSDO = 0, IOVDD: 2.7 V to 5.5 V
    11. 5.11 Timing Requirements: Read and Daisy Chain, FSDO = 1, IOVDD: 2.7 V to 5.5 V
    12. 5.12 Timing Diagrams
    13. 5.13 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) Architecture
      2. 6.3.2 R-2R Ladder DAC
      3. 6.3.3 Programmable Gain Output Buffer
      4. 6.3.4 Sense Pins
      5. 6.3.5 DAC Register Structure
        1. 6.3.5.1 Output Update
        2. 6.3.5.2 Software Clear
          1. 6.3.5.2.1 Software Reset Mode
      6. 6.3.6 Internal Reference
      7. 6.3.7 Power-Supply Sequence
        1. 6.3.7.1 Power-On Reset (POR)
      8. 6.3.8 Thermal Alarm
    4. 6.4 Device Functional Modes
      1. 6.4.1 Power Down Mode
    5. 6.5 Programming
      1. 6.5.1 Stand-Alone Operation
      2. 6.5.2 Daisy-Chain Operation
      3. 6.5.3 Frame Error Checking
  8. 7 Register Map
    1. 7.1 Registers
  9. 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 Key Components
        2. 8.2.2.2 Compensation Capacitor
        3. 8.2.2.3 Gain Stage
        4. 8.2.2.4 Attenuation and Buffer Stage
        5. 8.2.2.5 External Power Supply
        6. 8.2.2.6 Protection Design
        7. 8.2.2.7 Design Accuracy
      3. 8.2.3 Application Curves
    3. 8.3 Initialization Set Up
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 ドキュメントの更新通知を受け取る方法
    2. 9.2 サポート・リソース
    3. 9.3 Trademarks
    4. 9.4 静電気放電に関する注意事項
    5. 9.5 用語集
  11. 10Revision History
  12. 11Mechanical, 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

6.5.2 Daisy-Chain Operation

For systems that contain several DACx1401 devices, the SDO pin can be used to daisy-chain devices together. The daisy-chain feature is useful in reducing the number of serial interface lines. The SDO pin must be enabled by setting the SDO-EN bit in the SPICONFIG register before initiating daisy-chain operation.

The first falling edge on the SYNC pin starts the operation cycle (see Figure 6-4). If more than 24 clock pulses are applied while the SYNC pin is kept low, the data ripple out of the shift register and are clocked out on the SDO pin, either on the falling edge or rising edge of SCLK according to the FSDO bit. By connecting the SDO output of the first device to the SDI input of the next device in the chain, a multiple-device interface is constructed (Figure 6-3).

GUID-20230526-SS0I-H2CS-ZTNG-8KCVBX1GTCSP-low.svg Figure 6-3 Daisy-Chain Setup

Each device in the system requires 24 clock pulses. As a result the total number of clock cycles must be equal to 24 × N, where N is the total number of devices in the daisy chain. When the serial transfer to all devices is complete the SYNC signal is taken high. This action transfers the data from the SPI shift registers to the internal register of each device in the daisy chain, and prevents any further data from being clocked into the input shift register.

GUID-20230208-SS0I-QNKL-NXKX-MBQQRJFNN4XJ-low.svg Figure 6-4 Serial Interface Daisy-Chain Write Cycle