JAJSE78C August   2017  – January 2019 DAC60504 , DAC70504 , DAC80504

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      ブロック概略図
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Digital-to-Analog Converter (DAC)
        1. 9.3.1.1 DAC Transfer Function
        2. 9.3.1.2 Output Amplifiers
        3. 9.3.1.3 DAC Register Structure
          1. 9.3.1.3.1 DAC Register Synchronous and Asynchronous Updates
          2. 9.3.1.3.2 Broadcast DAC Register
      2. 9.3.2 Internal Reference
        1. 9.3.2.1 Reference Divider
        2. 9.3.2.2 Solder Heat Reflow
      3. 9.3.3 Device Reset Options
        1. 9.3.3.1 Power-on-Reset (POR)
        2. 9.3.3.2 Software Reset
    4. 9.4 Device Functional Modes
      1. 9.4.1 Stand-Alone Operation
      2. 9.4.2 Daisy-Chain Operation
      3. 9.4.3 Frame Error Checking
      4. 9.4.4 Power-Down Mode
    5. 9.5 Programming
    6. 9.6 Register Map
      1. 9.6.1 NOP Register (address = 0x00) [reset = 0x0000]
        1. Table 9. NOP Register Field Descriptions
      2. 9.6.2 DEVICE ID Register (address = 0x01) [reset = 0x---]
        1. Table 10. DEVICE ID Field Descriptions
      3. 9.6.3 SYNC Register (address = 0x2) [reset = 0xFF00]
        1. Table 11. SYNC Register Field Descriptions
      4. 9.6.4 CONFIG Register (address = 0x3) [reset = 0x0000]
        1. Table 12. CONFIG Register Field Descriptions
      5. 9.6.5 GAIN Register (address = 0x04) [reset = 0x---]
        1. Table 13. GAIN Register Field Descriptions
      6. 9.6.6 TRIGGER Register (address = 0x05) [reset = 0x0000]
        1. Table 14. TRIGGER Register Field Descriptions
      7. 9.6.7 BRDCAST Register (address = 0x6) [reset = 0x0000]
        1. Table 15. BRDCAST Register Field Descriptions
      8. 9.6.8 STATUS Register (address = 0x7) [reset = 0x0000]
        1. Table 16. STATUS Register Field Descriptions
      9. 9.6.9 DACx Register (address = 0x8 to 0xF) [reset = 0x0000 or 0x8000]
        1. Table 17. DACx Register Field Descriptions
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Interfacing to a Microcontroller
      2. 10.1.2 Programmable Current Source Circuit
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curve
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13デバイスおよびドキュメントのサポート
    1. 13.1 ドキュメントのサポート
      1. 13.1.1 関連資料
    2. 13.2 関連リンク
    3. 13.3 ドキュメントの更新通知を受け取る方法
    4. 13.4 コミュニティ・リソース
    5. 13.5 商標
    6. 13.6 静電気放電に関する注意事項
    7. 13.7 Glossary
  14. 14メカニカル、パッケージ、および注文情報

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

10.1.2 Programmable Current Source Circuit

The DACx0504 can be integrated into the circuit in Figure 75 to implement an improved Howland current pump for precise voltage to current conversions. Bidirectional current flow and high voltage compliance are two features of the circuit. With a matched resistor network, the load current of the circuit is shown by Equation 2.

Equation 2. DAC80504 DAC70504 DAC60504 EQ2_slasel1.gif

The value of R3 in Equation 2 can be reduced to increase the output current drive of U3. U3 can drive ±20 mV in both directions with voltage compliance limited up to 15 V by the U3 voltage supply. Elimination of the circuit compensation capacitor C1 in the circuit is not suggested as a result of the change in the output impedance ZO, according to Equation 3.

Equation 3. DAC80504 DAC70504 DAC60504 EQ3_slase73.gif

As shown in Equation 3, with matched resistors, ZO is infinite and the circuit is optimum for use as a current source. However, if unmatched resistors are used, ZO is positive or negative with negative output impedance being a potential cause of oscillation. Therefore, by incorporating C1 into the circuit, possible oscillation problems are eliminated. The value of C1 can be determined for critical applications; for most applications, however, a value of several pF is suggested.

DAC80504 DAC70504 DAC60504 dac80504-programmable-bidirectional-current-source.gifFigure 75. Programmable Bidirectional Current Source Circuit