SLPS814 November   2025 RES21A-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  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 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 DC Measurement Configurations
    2. 6.2 AC Measurement Configurations
    3. 6.3 Error Notation and Units
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Ratiometric Matching for Low Gain Error
        1. 7.3.1.1 Absolute and Ratiometric Tolerances
      2. 7.3.2 Ratiometric Drift
      3. 7.3.3 Long-Term Stability
      4. 7.3.4 Humidity Resilience
      5. 7.3.5 Ultra-Low Noise
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Amplifier Feedback Circuit
        1. 8.1.1.1 Amplifier Feedback Circuit Example
      2. 8.1.2 Voltage Divider Circuit
        1. 8.1.2.1 Voltage Divider Circuit Example
        2. 8.1.2.2 Voltage-Divider Circuit Drift
      3. 8.1.3 Discrete Difference Amplifier
        1. 8.1.3.1 Difference-Amplifier Common-Mode Rejection Analysis
        2. 8.1.3.2 Difference-Amplifier Gain Error Analysis
      4. 8.1.4 Discrete Instrumentation Amplifiers
      5. 8.1.5 Fully Differential Amplifier
      6. 8.1.6 Unconventional Circuits
        1. 8.1.6.1 Single-Channel Voltage Divider
        2. 8.1.6.2 Single-Channel Amplifier Gain
          1. 8.1.6.2.1 Gain Scaling the RES60A-Q1 With the RES21A-Q1
        3. 8.1.6.3 Unconventional Instrumentation Amplifiers
    2. 8.2 Typical Application
      1. 8.2.1 Common-Mode Shifting Input Stage
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Examples
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
        1. 9.1.1.1 PSpice® for TI
        2. 9.1.1.2 TINA-TI™ Simulation Software (Free Download)
        3. 9.1.1.3 TI Reference Designs
        4. 9.1.1.4 Analog Filter Designer
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

3 Description

The RES21A-Q1 is a matched pair of resistive dividers, implemented in thin-film SiCr with Texas Instruments' modern, high-performance, analog CMOS process. The device has a nominal input resistance of 10kΩ, supporting higher divider voltages than the RES11A-Q1, and is available in several nominal ratios to meet a wide array of system needs. Use the RES21A-Q1 in an inverse gain configuration by simply rotating the device placement by 180°. This feature supports layout reuse and increases flexibility for applications such as discrete instrumentation or difference amplifier implementations.

The RES21A-Q1 series features high ratio-matching precision, with the measured ratio of each divider within ±0.05% (±500ppm) of the nominal. This precision is maintained over the temperature range, with a maximum ratio drift of only ±2ppm/°C. Additionally, the biased long-term stability of the device has been proven through thorough characterization.

The RES21A-Q1 is automotive qualified under AEC-Q200 temperature grade 1. The temperature range is specified from –40°C to +125°C. The device is offered in an 8‑pin, SOT‑23-THIN package, with a body size of 2.9mm × 1.6mm (body size is a nominal value and does not include pins).

Package Information
PART NUMBERPACKAGE(1)PACKAGE SIZE(2)
RES21A-Q1DDF (SOT-23-THIN, 8) 2.9mm × 2.8mm
(1) For more information, see Section 11.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.
Device Information
PART NUMBER NOMINAL RATIO
RES21A10-Q1 1:1
RES21A15-Q1(1) 1:1.5
RES21A16-Q1 1:1.667
RES21A20-Q1(1) 1:2
RES21A25-Q1 1:2.5
RES21A30-Q1(1) 1:3
RES21A40-Q1 1:4
RES21A50-Q1(1) 1:5
RES21A90-Q1 1:9
RES21A00-Q1 1:10
(1) Preview information (not Advanced Information).

 

RES21A-Q1 Functional Block DiagramFunctional Block Diagram
RES21A-Q1 Excellent Ratio Matching for Best CMRRExcellent Ratio Matching for Best CMRR