SNAS279F April   2005  – July 2016 ADC084S021


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Transfer Function
      2. 8.3.2 Analog Inputs
      3. 8.3.3 Digital Inputs and Outputs
    4. 8.4 Device Functional Modes
      1. 8.4.1 Track Mode
      2. 8.4.2 Hold Mode
    5. 8.5 Register Maps
      1. 8.5.1 Register Description
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
    1. 10.1 Power Management
    2. 10.2 Noise Considerations
  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 Device Nomenclature
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9 Application and Implementation


Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

9.1 Application Information

Figure 49 shows a typical application of the ADC084S021. Power is provided, in this example, by the Texas Instruments LP2950 low-dropout voltage regulator, available in a variety of fixed and adjustable output voltages. The power supply pin is bypassed with a capacitor network located close to the ADC084S021.

Because the reference for the ADC084S021 is the supply voltage, any noise on the supply degrades device noise performance. Use a dedicated linear regulator for this device, or provide sufficient decoupling from other circuitry to keep noise off the ADC084S021 supply pin. Because of the low power requirements of the ADC084S021, it is also possible to use a precision reference as a power supply to maximize performance. The four-wire interface is also shown connected to a microprocessor or DSP.

9.2 Typical Application

ADC084S021 20124513.gif Figure 49. Typical Application Circuit

9.2.1 Design Requirements

In this application, the power consumption of the ADC084S021 must not exceed 1 mW and the throughput may range from 50 ksps to 200 ksps.

9.2.2 Detailed Design Procedure

The two largest factors that impact the power consumption of the ADC084S021 are the supply voltage and the throughput. According to Figure 50, a supply voltage of 3 V allows a throughput of up to 200 ksps at less than
1-mW power consumption. If a supply voltage of 5 V is chosen then the maximum throughput achievable is about 40 ksps, which does not meet the design requirements. Select a supply voltage of 3 V with a FCLK of
3.2 MHz to meet all of the design requirements.

9.2.3 Application Curve

ADC084S021 20124561.png Figure 50. Power Consumption vs Throughput