SBOS092B June   1998  – January 2025 XTR106

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 Recommended Operating Conditions
    3. 5.3 Thermal Information
    4. 5.4 Electrical Characteristics
    5. 5.5 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Linearization
      2. 6.3.2 Reverse-Voltage Protection
      3. 6.3.3 Overvoltage Surge Protection
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 External Transistor
      2. 7.1.2 Loop Power Supply
      3. 7.1.3 Bridge Balance
      4. 7.1.4 Underscale Current
      5. 7.1.5 Low-Impedance Bridges
      6. 7.1.6 Other Sensor Types
      7. 7.1.7 Radio Frequency Interference
      8. 7.1.8 Error Analysis
    2. 7.2 Typical Applications
    3. 7.3 Layout
    4. 7.4 Layout Guidelines
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
    2. 8.2 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.1.8 Error Analysis

Table 7-1 shows how to calculate the effect various error sources have on circuit accuracy. A sample error calculation for a typical bridge sensor measurement circuit (5kΩ bridge, VREF = 5V, VFS = 50mV) is provided. The results reveal the XTR106 excellent accuracy, in this case 1.2% unadjusted. Adjusting gain and offset errors improves circuit accuracy to 0.33%. These are worst-case errors; maximum values were used in the calculations and all errors were assumed to be positive (additive). The XTR106 achieves performance that is difficult to obtain with discrete circuitry and requires less board space.

Table 7-1 Error Calculation
SAMPLE ERROR CALCULATION(1)
Bridge Impedance (RB) 5kΩ Full Scale Input (VFS) 50mV
Ambient Temperature Range (ΔTA) 20°C Excitation Voltage (VREF) 5V
Supply Voltage Change (ΔV+) 5V Common-Mode Voltage Change (ΔCM) 25mV (= VFS/2)
ERROR SOURCE SAMPLE ERROR EQUATION ERROR CALCULATION ERROR (ppm of Full Scale)
UNADJ ADJUST
INPUT
Input offset voltage VOS/VFS · 106 200μV/50mV · 106 2000 0
vs common-mode CMRR · ΔCM/VFS · 106 50μV/V · 0.025V/50mV · 106 25 25
vs power supply (VOS vs V+) · (ΔV+)/VFS · 106 3μV/V · 5V/50mV · 106 300 300
Input bias current CMRR · IB · (RB/2)/VFS · 106 50μV/V · 25nA · 2.5kΩ/50mV · 106 0.1 0
Input offset current IOS · RB/VFS · 106 3nA · 5kΩ/50mV · 106 300 0
Total Input Error 2625 325
EXCITATION
Voltage reference accuracy VREF Accuracy (%)/100% · 106 0.25%/100% · 106 2500 0
vs supply (VREF vs V+) · (ΔV+) · (VFS/VREF) 20ppm/V · 5V (50mV/5V) 1 1
Total Excitation Error 2501 1
GAIN
Span Span Error (%)/100% · 106 0.2%/100% · 106 2000 0
Nonlinearity Nonlinearity (%)/100% · 106 0.01%/100% · 106 100 100
Total Gain Error 2100 100
OUTPUT
Zero output | IZERO – 4mA |/16000μΑ · 106 25μΑ/16000μΑ · 106 1563 0
vs supply (IZERO vs V+) · (ΔV+)/16000μΑ · 106 0.2μA/V · 5V/16000μΑ · 106 62.5 62.5
Total Output Error 1626 63
DRIFT (ΔT A = 20°C)
Input offset voltage Drift · ΔTA/(VFS) · 106 1.5μV/°C · 20°C/(50mV) · 106 600 600
Input offset current (typical) Drift · ΔTA· RB/(VFS) · 106 5pA/°C · 20°C · 5kΩ/(50mV) · 106 10 10
Voltage reference accuracy 35ppm/°C · 20°C 700 700
Span 225ppm/°C · 20°C 500 500
Zero output Drift · ΔΤΑ/16000μΑ · 106 0.9μA/°C · 20°C/16000μA · 106 1125 1125
Total Drift Error 2936 2936
NOISE (0.1Hz to 10Hz, typical)
Input offset voltage Vn(p-p)/VFS · 106 0.6μV/50mV · 106 12 12
Zero output IZERO Noise / 16000μΑ · 106 0.035μΑ/16000μΑ · 106 2.2 2.2
Thermal RB noise [√2· √(R B/2)/1kΩ · 4nV/√Hz · √10Hz]/VFS · 106 [√2 · √2.5kΩ/1kΩ· 4nV/√Hz · √10Hz]]/50mV · 106 0.6 0.6
Input current noise (in · 40.8 · √2 · RB/2)/VFS · 106 (200fA/√Hz · 40.8 · √2 · 2.5kΩ)/50mV· 106 0.6 0.6
Total Noise Error 15 15
TOTAL ERROR: 11803 3340
1.18% 0.33%
(1) All errors are minimum and maximum, and referred to input, unless otherwise stated.