SLVSA79A April   2010  – September 2016 TL1963A-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Adjustable Operation
      2. 7.3.2 Output Capacitance and Transient Response
      3. 7.3.3 Overload Recovery
      4. 7.3.4 Output Voltage Noise
      5. 7.3.5 Protection Features
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Output Capacitance and Transient Response
    2. 8.2 Typical Application
      1. 8.2.1 Adjustable Output Operation
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Fixed Operation
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Paralleling Regulators for Higher Output Current
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Calculating Junction Temperature
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

10 Layout

10.1 Layout Guidelines

For best performance, follow the guidelines below:

  • All traces must be as short as possible.
  • Use wide traces for IN, OUT, and GND to minimize the parasitic electrical effects.
  • A minimum output capacitor of 10 µF with an ESR of 3 Ω or less is recommended to prevent oscillations. X5R and X7R dielectrics are preferred.
  • Place the output capacitor as close as possible to the OUT pin of the device.
  • The exposed thermal pad of the KTT package must be connected to a wide ground plane for effective heat dissipation.

10.2 Layout Example

TL1963A-Q1 layoutexto263_slvsa79a.gif Figure 36. TO-263 (KTT) Layout Example

10.3 Calculating Junction Temperature

Given an output voltage of 3.3 V, an input voltage range of 4 V to 6 V, an output current range of 0 mA to 500 mA, and a maximum ambient temperature of 50°C, what is the maximum junction temperature?

The power dissipated by the device is equal to Equation 11.

Equation 11. IOUT(MAX)(VIN(MAX) – VOUT) + IGND(VIN(MAX))

where

  • IOUT(MAX) = 500 mA
  • VIN(MAX) = 6 V
  • IGND at (IOUT = 500 mA, VIN = 6 V) = 10 mA

So, P = 500 mA (6 V – 3.3 V) + 10 mA (6 V) = 1.41 W.

Using a KTT package, the thermal resistance is in the range of 23°C/W to 33°C/W, depending on the copper area. So the junction temperature rise above ambient is approximately equal to Equation 12.

Equation 12. 1.41 W × 28°C/W = 39.5°C

The maximum junction temperature is then be equal to the maximum junction-temperature rise above ambient plus the maximum ambient temperature or Equation 13.

Equation 13. TJMAX = 50°C + 39.5°C = 89.5°C