SLASEL0B October   2019  – June 2020 DAC11001A , DAC81001 , DAC91001

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Functional Block Diagram
      2.      High-Precision, Control-Loop Circuit
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1      Absolute Maximum Ratings
    2. 7.2      ESD Ratings
    3. 7.3      Recommended Operating Conditions
    4. 7.4      Thermal Information Package
    5. 7.5      Electrical Characteristics
    6. Table 1. Timing Requirements: Write, 4.5 V ≤ DVDD ≤ 5.5 V
    7. Table 2. Timing Requirements: Write, 2.7 V ≤ DVDD < 4.5 V
    8. Table 3. Timing Requirements: Read and Daisy-Chain Write, 4.5 V ≤ DVDD ≤ 5.5 V
    9. Table 4. Timing Requirements: Read and Daisy-Chain Write, 2.7 V ≤ DVDD < 4.5 V
    10. 7.6      Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Digital-to-Analog Converter Architecture
      2. 8.3.2 External Reference
      3. 8.3.3 Output Buffers
      4. 8.3.4 Internal Power-On Reset (POR)
      5. 8.3.5 Temperature Drift and Calibration
      6. 8.3.6 DAC Output Deglitch Circuit
    4. 8.4 Device Functional Modes
      1. 8.4.1 Fast-Settling Mode and THD
      2. 8.4.2 DAC Update Rate Mode
    5. 8.5 Programming
      1. 8.5.1 Daisy-Chain Operation
      2. 8.5.2 CLR Pin Functionality and Software Clear
      3. 8.5.3 Output Update (Synchronous and Asynchronous)
        1. 8.5.3.1 Synchronous Update
        2. 8.5.3.2 Asynchronous Update
      4. 8.5.4 Software Reset Mode
    6. 8.6 Register Map
      1. 8.6.1 NOP Register (address = 00h) [reset = 0x000000h]
        1. Table 9. NOP Register Field Descriptions
      2. 8.6.2 DAC-DATA Register (address = 01h) [reset = 0x000000h]
        1. Table 10. DAC-DATA Register Field Descriptions
      3. 8.6.3 CONFIG1 Register (address = 02h) [reset = 004C80h for bits [23:0]]
        1. Table 11. CONFIG1 Register Field Descriptions
      4. 8.6.4 DAC-CLEAR-DATA Register (address = 03h) [reset = 000000h for bits [23:0]]
        1. Table 12. DAC-CLEAR-DATA Register Field Descriptions
      5. 8.6.5 TRIGGER Register (address = 04h) [reset = 000000h for bits [23:0]]
        1. Table 13. TRIGGER Register Field Descriptions
      6. 8.6.6 STATUS Register (address = 05h) [reset = 000000h for bits [23:0]]
        1. Table 14. STATUS Register Field Descriptions
      7. 8.6.7 CONFIG2 Register (address = 06h) [reset = 000040h for bits [23:0]]
        1. Table 15. CONFIG2 Register Field Descriptions
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Source Measure Unit (SMU)
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Battery Test Equipment (BTE)
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 High-Precision Control Loop
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curves
      4. 9.2.4 Arbitrary Waveform Generation (AWG)
        1. 9.2.4.1 Design Requirements
        2. 9.2.4.2 Detailed Design Procedure
        3. 9.2.4.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 Interfacing to a Processor
      2. 9.3.2 Interfacing to a Low-Jitter LDAC Source
      3. 9.3.3 Embedded Resistor Configurations
        1. 9.3.3.1 Minimizing Bias Current Mismatch
        2. 9.3.3.2 2x Gain configuration
        3. 9.3.3.3 Generating Negative Reference
    4. 9.4 What to Do and What Not to Do
      1. 9.4.1 What to Do
      2. 9.4.2 What Not to Do
    5. 9.5 Initialization Set Up
  10. 10Power Supply Recommendations
    1. 10.1 Power-Supply Sequencing
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Related Links
    4. 12.4 Receiving Notification of Documentation Updates
    5. 12.5 Support Resources
    6. 12.6 Trademarks
    7. 12.7 Electrostatic Discharge Caution
    8. 12.8 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

9.2.1.2 Detailed Design Procedure

The DAC11001A is an excellent choice for this application to meet the 20-bit resolution requirement. Switch SW is used to toggle between force-voltage and force-current modes, as shown in Figure 56. The OPA828 is a high-precision amplifier that provides a good balance between dc and ac performance, and can supply ±30-mA output current. The INA188 is a zero-drift instrumentation amplifier with gain selected with an external resistor. The external resistor is not shown in the drawing for simplicity. The gain resistor is not required for a gain of 1. Equation 2 shows the calculation of the voltage gain when switch SW is in position 1.

Equation 2. DAC11001A DAC91001 DAC81001 dac11001-smu-voltage-gain-eq.gif

Precision reference sources are available at 5 V or less. Use a ±5-V reference with a 2x gain configuration to get an output of ±10 V. The DAC output amplifier sets the gain at 2, assuming GV = 1, as shown in Equation 3. R1 and R2 are 1-kΩ each. Equation 3 shows the calculation for the current gain when the switch is in the position 2.

Equation 3. DAC11001A DAC91001 DAC81001 dac11001-smu-current-gain-eq.gif

In order to get ±20-mA output current range with R1 = R2, RSENSEx GI must be 500. Choose GI as 50 so that RSENSE can be 10-Ω. For a ±20-mA output current, the voltage drop across RSENSE is ±200-mV. In case the design requires a lower voltage headroom, choose a higher value for GI and a smaller resistance value for RSENSE.

There is no equation to select C1 and C2. The values of C1 and C2 depend on the stability criteria of the reference buffers when driving the reference inputs of DACx1001. The values are obtained through simulation. For the OPA828, use C1 = C2 = 100 pF. The 1-MΩ resistors in the circuit are used for making sure the amplifiers are not left in an open-loop state.