SLVSA02B September   2009  – January 2019 TPS60151

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Schematic
      2.      Efficiency vs Input Voltage
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 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 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Enable
      2. 8.3.2 Output Reverse Current Protection
      3. 8.3.3 Undervoltage Lockout
      4. 8.3.4 Thermal Shutdown Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Soft Start
      2. 8.4.2 Normal Mode and Skip Mode Operation
      3. 8.4.3 Over-current Protection and Short-Circuit Protection
  9. 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
        1. 9.2.2.1 Capacitor Selection
      3. 9.2.3 Application Curves
    3. 9.3 System Example
      1. 9.3.1 Circuit for Driving White LEDs
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2.1 Capacitor Selection

For minimum output voltage ripple, the output capacitor (COUT) should be a surface-mount ceramic capacitor. Tantalum capacitors generally have a higher effective series resistance (ESR) and may contribute to higher output voltage ripple. Leaded capacitors also increase ripple due to the higher inductance of the package itself. To achieve the best operation with low input voltage and high load current, the input and flying capacitors (CIN and CFLY, respectively) should also be surface-mount ceramic types.

TPS60151 caps_lvsa02.gifFigure 11. Capacitors

Generally, CFLY can be calculated by the following simple equation,

Equation 2. TPS60151 eq_qchg_lvs888.gif

Both equation should be same, TPS60151 eq_inline_lvs888.gif

Equation 3. TPS60151 eq_cfly_lvs888.gif

If ILOAD = 140 mA, f = 1.5 MHz, and ΔVCFLY = 100 mV, the minimum value of the flying capacitor should be 1 μF.

Output capacitance, COUT, is also strongly related to output ripple voltage and loop stability,

Equation 4. TPS60151 eq_ripple_lvs888.gif

The minimum output capacitance for all output levels is 2.2 μF due to control stability. Larger ceramic capacitors or low ESR capacitors can be used to lower the output ripple voltage.

Table 1. Suggested Capacitors (Input / Output / Flying Capacitor)

VALUE DIELECTRIC MATERIAL PACKAGE SIZE RATED VOLTAGE
4.7 μF X5R or X7R 0603 10 V
2.2 μF X5R or X7R 0603 10 V

The efficiency of the charge pump regulator varies with the output voltage, the applied input voltage and the load current.

The approximate efficiency in normal operating mode is given by:

Equation 5. TPS60151 eq_eff_lvs888.gif
Equation 6. TPS60151 eq_eff2_lvs888.gif