SLVSGU9 October   2024 TPS62810-EP , TPS62811-EP , TPS62812-EP , TPS62813-EP

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Parameter Measurement Information
    1. 7.1 Schematic
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Precise Enable
      2. 8.3.2 COMP/FSET
      3. 8.3.3 MODE/SYNC
      4. 8.3.4 Spread Spectrum Clocking (SSC)
      5. 8.3.5 Undervoltage Lockout (UVLO)
      6. 8.3.6 Power-Good Output (PG)
      7. 8.3.7 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Pulse Width Modulation (PWM) Operation
      2. 8.4.2 Power Save Mode Operation (PWM/PFM)
      3. 8.4.3 100% Duty-Cycle Operation
      4. 8.4.4 Current Limit and Short-Circuit Protection
      5. 8.4.5 Foldback Current Limit and Short-Circuit Protection
      6. 8.4.6 Output Discharge
      7. 8.4.7 Soft Start/Tracking (SS/TR)
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Programming the Output Voltage
      2. 9.1.2 Inductor Selection
      3. 9.1.3 Capacitor Selection
        1. 9.1.3.1 Input Capacitor
        2. 9.1.3.2 Output Capacitor
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 Voltage Tracking
      2. 9.3.2 Synchronizing to an External Clock
    4. 9.4 Power Supply Recommendations
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

9.1.2 Inductor Selection

The TPS6281x-EP device is designed for a nominal 0.47µH inductor with a typical switching frequency of 2.25MHz. Larger values can be used to achieve a lower inductor current ripple, but can have a negative impact on efficiency and transient response. Smaller values than 0.47µH cause a larger inductor current ripple, which causes larger negative inductor current in forced PWM mode at low or no output current. For a higher or lower nominal switching frequency, the inductance must be changed accordingly.

The inductor selection is affected by several effects like the following:

  • Inductor ripple current
  • Output ripple voltage
  • PWM-to-PFM transition point
  • Efficiency
In addition, the selected inductor must be rated for appropriate saturation current and DC resistance (DCR). Equation 8 calculates the maximum inductor current.

Equation 8. TPS62810-EP TPS62811-EP TPS62812-EP TPS62813-EP
Equation 9. TPS62810-EP TPS62811-EP TPS62812-EP TPS62813-EP

where

  • IL(max) is the maximum inductor current
  • ΔIL(max) is the peak-to-peak inductor ripple current
  • Lmin is the minimum inductance at the operating point
Table 9-1 Typical Inductors
TYPEINDUCTANCE [µH]CURRENT [A] (1)FOR DEVICENOMINAL SWITCHING FREQUENCYDIMENSIONS [L × B × H] mmMANUFACTURER(2)

OPERATION AT –55°C

ML433PYA601MLZ0.6µH, ±20%10.4TPS62810-EP, TPS62813-EP, TPS62812-EP2.25MHz4 × 4 × 2.1CoilcraftYes
ML433PYA401MLZ0.4µH, ±20%12.5TPS62810-EP, TPS62813-EP, TPS62812-EP2.25MHz4 × 4 × 2.1CoilcraftYes
XFL4015-471ME0.47µH, ±20%3.5TPS62813-EP, TPS62812-EP2.25MHz4 × 4 × 1.6CoilcraftNo
XEL4020-561ME0.56µH, ±20%9.9TPS62810-EP, TPS62813-EP, TPS62812-EP2.25MHz4 × 4 × 2.1CoilcraftNo
XEL4030-471ME0.47µH, ±20%12.3TPS62810-EP, TPS62813-EP, TPS62812-EP2.25MHz4 × 4 × 3.1CoilcraftNo
XEL3515-561ME0.56µH, ±20%4.5TPS62813-EP, TPS62812-EP2.25MHz3.5 × 3.2 × 1.5CoilcraftNo
XFL3012-331MEB0.33µH, ±20%2.6TPS62811-EP, TPS62812-EP≥ 3.5MHz3 × 3 × 1.3CoilcraftNo
XPL2010-681ML0.68µH, ±20%1.5TPS62811-EP2.25MHz2 × 1.9 × 1CoilcraftNo
DFE252012PD-R47M0.47µH, ±20%see data sheetTPS62811-EP, TPS62813-EP, TPS62812-EP2.25MHz2.5 × 2 × 1.2MurataNo
(1) Lower of IRMS at 20°C rise or ISAT at 20% drop.
(2) See the Third-party Products Disclaimer.

Calculating the maximum inductor current using the actual operating conditions gives the minimum saturation current of the inductor needed. TI recommends a margin of about 20% to add. A larger inductor value is also useful to get lower ripple current, but increases the transient response time and size as well.