SLVSDD1E December   2017  – January 2019 TPS62800 , TPS62801 , TPS62802 , TPS62806 , TPS62807 , TPS62808

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
      2.      Efficiency vs. IOUT at 1.2VOUT
  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 Smart Enable and Shutdown (EN)
      2. 8.3.2 Softstart
      3. 8.3.3 VSEL/MODE Pin
        1. 8.3.3.1 Output Voltage Selection (R2D Converter)
        2. 8.3.3.2 Mode Selection: Power Save Mode / Forced PWM Operation
      4. 8.3.4 Undervoltage Lockout (UVLO)
      5. 8.3.5 Switch Current Limit / Short Circuit Protection
      6. 8.3.6 Thermal Shutdown
      7. 8.3.7 Output Voltage Discharge
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power Save Mode Operation
      2. 8.4.2 Forced PWM Mode Operation
      3. 8.4.3 100% Mode Operation
      4. 8.4.4 Optimized Transient Performance from PWM to PFM Mode Operation
  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 Custom Design With WEBENCH® Tools
        2. 9.2.2.2 Inductor Selection
        3. 9.2.2.3 Output Capacitor Selection
        4. 9.2.2.4 Input Capacitor Selection
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Custom Design With WEBENCH® Tools
    3. 12.3 Related Links
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2.2 Inductor Selection

The inductor value affects the peak-to-peak ripple current, the PWM-to-PFM transition point, the output voltage ripple and the efficiency. The selected inductor has to be rated for its DC resistance and saturation current. The inductor ripple current (ΔIL) decreases with higher inductance and increases with higher VIN or VOUT and can be estimated according to Equation 1.

Equation 2 calculates the maximum inductor current under static load conditions. The saturation current of the inductor should be rated higher than the maximum inductor current, as calculated with Equation 2. This is recommended because during a heavy load transient the inductor current rises above the calculated value. A more conservative way is to select the inductor saturation current according to the high side MOSFET switch current limit, ILIMF.

Equation 1. TPS62800 TPS62801 TPS62802 TPS62806 TPS62807 TPS62808 eq4_dil_lvs941.gif
Equation 2. TPS62800 TPS62801 TPS62802 TPS62806 TPS62807 TPS62808 eq5_ilmax_lvs941.gif

where

  • f = Switching Frequency
  • L = Inductor Value
  • ΔIL= Peak to Peak inductor ripple current
  • ILmax = Maximum Inductor current

Table 3 shows a list of possible inductors.

Table 3. List of Possible Inductors(1)

INDUCTANCE [µH] INDUCTOR SERIES SIZE IMPERIAL (METRIC) DIMENSIONS L x W X T SUPPLIER(1)
0.47 DFE18SAN_G0 0603 (1608) 1.6mm x 0.8mm x 1.0mm max Murata
0.47 HTEB16080F 0603 (1608) 1.6mm x 0.8mm x 0.6mm max. Cyntec
0.47 HTET1005FE 0402 (1005) 1.0mm x 0.5mm x 0.65mm max. Cyntec
0.47 TFM160808ALC 0603 (1608) 1.6mm x 0.8mm x 0.8mm max. TDK
1.0 DFE201610E 0806 (201610) 2.0mm x 1.6mm x 1.0mm max Murata