JAJS398F January   2009  – April 2018 DAC7568 , DAC8168 , DAC8568

PRODUCTION DATA.  

  1. 特長
  2. アプリケーション
  3. 概要
    1.     ブロック図
  4. 改訂履歴
  5. 概要(続き)
  6. Device Comparison Table
  7. Pin Configuration and Functions
    1.     Pin Functions
  8. Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 Electrical Characteristics
    3. 8.3 Timing Requirements
    4. 8.4 Typical Characteristics: Internal Reference
    5. 8.5 Typical Characteristics: DAC at AVDD = 5.5 V
    6. 8.6 Typical Characteristics: DAC at AVDD = 3.6 V
    7. 8.7 Typical Characteristics: DAC at AVDD = 2.7 V
  9. Detailed Description
    1. 9.1 Functional Block Diagram
    2. 9.2 Feature Description
      1. 9.2.1  Digital-to-Analog Converter (DAC)
      2. 9.2.2  Resistor String
      3. 9.2.3  Output Amplifier
      4. 9.2.4  Internal Reference
      5. 9.2.5  Serial Interface
      6. 9.2.6  Input Shift Register
        1. Table 1. DAC8568 Data Input Register Format
        2. Table 2. DAC8168 Data Input Register Format
        3. Table 3. DAC7568 Data Input Register Format
      7. 9.2.7  SYNC Interrupt
      8. 9.2.8  Power-on Reset to Zero Scale or Midscale
      9. 9.2.9  Clear Code Register and CLR Pin
      10. 9.2.10 Software Reset Function
      11. 9.2.11 Operating Examples: DAC7568/DAC8168/DAC8568
        1. Table 4.   1st: Write to Data Buffer A:
        2. Table 5.   2nd: Write to Data Buffer B:
        3. Table 6.   3rd: Write to Data Buffer G:
        4. Table 7.   4th: Write to Data Buffer H and Simultaneously Update all DACs:
        5. Table 8.   1st: Write to Data Buffer C and Load DAC C: DAC C Output Settles to Specified Value Upon Completion:
        6. Table 9.   2nd: Write to Data Buffer D and Load DAC D: DAC D Output Settles to Specified Value Upon Completion:
        7. Table 10. 3rd: Write to Data Buffer E and Load DAC E: DAC E Output Settles to Specified Value Upon Completion:
        8. Table 11. 4th: Write to Data Buffer F and Load DAC F: DAC F Output Settles to Specified Value Upon Completion:
        9. Table 12. 1st: Write Power-Down Command to DAC Channel A and DAC Channel B: DAC A and DAC B to 1kΩ.
        10. Table 13. 2nd: Write Power-Down Command to DAC Channel H: DAC H to 1kΩ.
        11. Table 14. 3rd: Write Power-Down Command to DAC Channel C and DAC Channel D: DAC C and DAC D to 100kΩ.
        12. Table 15. 4th: Write Power-Down Command to DAC Channel F: DAC F to 100kΩ.
        13. Table 16. 1st: Write Sequence for Enabling the DAC7568, DAC8168, and DAC8568 Internal Reference All the Time:
        14. Table 17. 2nd: Write Sequence to Power-Down All DACs to High-Impedance:
        15. Table 18. 1st: Write Sequence for Disabling the DAC7568, DAC8168, and DAC8568 Internal Reference All the Time (after this sequence, these devices require an external reference source to function):
        16. Table 19. 2nd: Write Sequence to Write Specified Data to All DACs:
    3. 9.3 Device Functional Modes
      1. 9.3.1 Enable/Disable Internal Reference
        1. 9.3.1.1 Static Mode
          1. Table 20. Write Sequence for Enabling Internal Reference (Static Mode) (Internal Reference Powered On—08000001h)
          2. Table 21. Write Sequence for Disabling Internal Reference (Static Mode) (Internal Reference Powered On—08000000h)
        2. 9.3.1.2 Flexible Mode
          1. Table 22. Write Sequence for Enabling Internal Reference (Flexible Mode) (Internal Reference Powered On—09080000h)
          2. Table 23. Write Sequence for Enabling Internal Reference (Flexible Mode) (Internal Reference Always Powered On—090A0000h)
          3. Table 24. Write Sequence for Disabling Internal Reference (Flexible Mode) (Internal Reference Always Powered Down—090C0000h)
          4. Table 25. Write Sequence for Switching from Flexible Mode to Static Mode for Internal Reference (Internal Reference Always Powered Down—09000000h)
      2. 9.3.2 LDAC Functionality
      3. 9.3.3 Power-Down Modes
        1. 9.3.3.1 DAC Power-Down Commands
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications - Microprocessor Interfacing
      1. 10.2.1 DAC7568/DAC8168/DAC8568 to an 8051 Interface
        1. 10.2.1.1 Detailed Design Procedure
          1. 10.2.1.1.1 Internal Reference
            1. 10.2.1.1.1.1 Supply Voltage
            2. 10.2.1.1.1.2 Temperature Drift
            3. 10.2.1.1.1.3 Noise Performance
            4. 10.2.1.1.1.4 Load Regulation
            5. 10.2.1.1.1.5 Long-Term Stability
            6. 10.2.1.1.1.6 Thermal Hysteresis
          2. 10.2.1.1.2 DAC Noise Performance
          3. 10.2.1.1.3 Bipolar Operation Using The DAC7568/DAC8168/DAC8568
      2. 10.2.2 DAC7568/DAC8168/DAC8568 to Microwire Interface
      3. 10.2.3 DAC7568/DAC8168/DAC8568 to 68HC11 Interface
  11. 11Layout
    1. 11.1 Layout Guidelines
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 デバイス・サポート
      1. 12.1.1 デバイスの項目表記
        1. 12.1.1.1 静的特性
          1. 12.1.1.1.1  分解能
          2. 12.1.1.1.2  最下位ビット(LSB)
          3. 12.1.1.1.3  最上位ビット(MSB)
          4. 12.1.1.1.4  相対精度または積分非直線性(INL)
          5. 12.1.1.1.5  微分非直線性(DNL)
          6. 12.1.1.1.6  フルスケール誤差
          7. 12.1.1.1.7  オフセット誤差
          8. 12.1.1.1.8  ゼロ・コード誤差
          9. 12.1.1.1.9  ゲイン誤差
          10. 12.1.1.1.10 フルスケール誤差ドリフト
          11. 12.1.1.1.11 オフセット誤差ドリフト
          12. 12.1.1.1.12 ゼロ・コード誤差ドリフト
          13. 12.1.1.1.13 ゲイン温度係数
          14. 12.1.1.1.14 電源除去率(PSRR)
          15. 12.1.1.1.15 単調性
        2. 12.1.1.2 動的特性
          1. 12.1.1.2.1  スルー・レート
          2. 12.1.1.2.2  出力電圧のセトリング時間
          3. 12.1.1.2.3  コード変化/デジタル-アナログ・グリッチ・エネルギー
          4. 12.1.1.2.4  デジタル・フィードスルー
          5. 12.1.1.2.5  チャネル間DCクロストーク
          6. 12.1.1.2.6  チャネル間ACクロストーク
          7. 12.1.1.2.7  信号対雑音比(SNR)
          8. 12.1.1.2.8  全高調波歪み(THD)
          9. 12.1.1.2.9  スプリアスフリー・ダイナミック・レンジ(SFDR)
          10. 12.1.1.2.10 信号対雑音比+歪み(SINAD)
          11. 12.1.1.2.11 DAC出力ノイズ密度
          12. 12.1.1.2.12 DAC出力ノイズ
          13. 12.1.1.2.13 フルスケール範囲(FSR)
    2. 12.2 関連リンク
    3. 12.3 ドキュメントの更新通知を受け取る方法
    4. 12.4 コミュニティ・リソース
    5. 12.5 商標
    6. 12.6 静電気放電に関する注意事項
    7. 12.7 Glossary
  13. 13メカニカル、パッケージ、および注文情報

Serial Interface

The DAC7568, DAC8168, and DAC8568 have a 3-wire serial interface (SYNC, SCLK, and DIN; see the Pin Configurations) compatible with SPI, QSPI, and Microwire interface standards, as well as most DSPs. See the Serial Write Operation timing diagram (Figure 1) for an example of a typical write sequence.

The DAC7568, DAC8168, and DAC8568 input shift register is 32-bits wide, consisting of four prefix bits (DB31 to DB28), four control bits (DB27 to DB24), 16 data bits (DB23 to DB4), and four feature bits. The 16 data bits comprise the 16-, 14-, or 12-bit input code. When writing to the DAC register (data transfer), bits DB0 to DB3 (for 16-bit operation), DB0 to DB5 (for 14-bit operation), and DB0 to DB7 (for 12-bit operation) are ignored by the DAC and should be treated as don't care bits (see Table 1 to Table 3). All 32 bits of data are loaded into the DAC under the control of the serial clock input, SCLK.

DB31 (MSB) is the first bit that is loaded into the DAC shift register and must be always set to '0'. It is followed by the rest of the 32-bit word pattern, left-aligned. This configuration means that the first 32 bits of data are latched into the shift register and any further clocking of data is ignored. When the DAC registers are being written to, the DAC7568, DAC8168, and DAC8568 receive all 32 bits of data, ignore DB31 to DB28, and decode the second set of four bits (DB27 to DB24) in order to determine the DAC operating/control mode (see ). Bits DB23 to DB20 are used to address selected DAC channels. The next 16/14/12 bits of data that follow are decoded by the DAC to determine the equivalent analog output. The last four data bits (DB0 to DB3 for DAC8568), last data six bits (DB0 to DB5 for DAC8168), or last eight data bits (DB0 to DB7 for DAC7568) are ignored in this case. For more details on these and other commands (such as write to LDAC register, power down DACs, etc.), see Table 1.

The data format is straight binary with all '0's corresponding to 0V output and all '1's corresponding to full-scale output. For all documentation purposes, the data format and representation used here is a true 16-bit pattern (that is, FFFFh for data word for full-scale) that the DAC7568, DAC8168, and DAC8568 require.

The write sequence begins by bringing the SYNC line low. Data from the DIN line are clocked into the 32-bit shift register on each falling edge of SCLK. The serial clock frequency can be as high as 50MHz, making the DAC7568, DAC8168, and DAC8568 compatible with high-speed DSPs. On the 32nd falling edge of the serial clock, the last data bit is clocked into the shift register and the shift register locks. Further clocking does not change the shift register data. After receiving the 32nd falling clock edge, the DAC7568, DAC8168, and DAC8568 decode the four control bits and four address bits and 16/14/12 data bits to perform the required function, without waiting for a SYNC rising edge. A new write sequence starts at the next falling edge of SYNC. A rising edge of SYNC before the 31st-bit sequence is complete resets the SPI interface; no data transfer occurs. After the 32nd falling edge of SCLK is received, the SYNC line may be kept low or brought high. In either case, the minimum delay time from the 32nd falling SCLK edge to the next falling SYNC edge must be met in order to properly begin the next cycle; see the Serial Write Operation timing diagram (Figure 1). To assure the lowest power consumption of the device, care should be taken that the levels are as close to each rail as possible. Refer to the 5.5V, 3.6V, and 2.7V Typical Characteristics sections for the Power-Supply Current vs Logic Input Voltage graphs (Figure 43, Figure 44, Figure 70, Figure 72, Figure 102, and Figure 103).