SLVS610C August   2006  â€“ October 2024 TL2842B , TL2843B , TL2844B , TL2845B , TL3842B , TL3843B , TL3844B , TL3845B

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  Reference Section Electrical Characteristics
    6. 5.6  Oscillator Section Electrical Characteristics
    7. 5.7  Error-Amplifier Section Electrical Characteristics
    8. 5.8  Current-Sense Section Electrical Characteristics
    9. 5.9  Output Section Electrical Characteristics
    10. 5.10 Undervoltage-Lockout Section Electrical Characteristics
    11. 5.11 Pulse-Width Modulator Section Electrical Characteristics
    12. 5.12 Supply Voltage Electrical Characteristics
    13. 5.13 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Functional Block Diagram
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Shutdown Technique
    3. 7.3 Open-Loop Laboratory Test Fixture
    4. 7.4 Typical Application
      1. 7.4.1 Application Curves
  9. 8 Device and Documentation Support
    1. 8.1 Related Links
    2. 8.2 Trademarks
    3. 8.3 Electrostatic Discharge Caution
    4. 8.4 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.1 Application Information

The error-amplifier configuration circuit is shown in Figure 7-1.

TL284xB TL384xB Error-Amplifier Configuration
A. Error amplifier can source or sink up to 0.5 mA.
Figure 7-1 Error-Amplifier Configuration

The current-sense circuit is shown in Figure 7-2.

TL284xB TL384xB Current-Sense Circuit
A. Peak current (IS) is determined by the formula: IS(max) = 1 V/RS
B. A small RC filter formed by resistor Rf and capacitor Cf may be required to suppress switch transients.
Figure 7-2 Current-Sense Circuit

The oscillator frequency is set using the circuit shown in Figure 7-3. The frequency is calculated as:

f = 1 / RTCT

For RT > 5 kΩ:

f ≉ 1.72 / RTCT

TL284xB TL384xB Oscillator SectionFigure 7-3 Oscillator Section