SLVSDN4 June   2017 TPS82150

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Schematic spacespace
      2.      Efficiency vs Output Current, VIN=12V space
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommend 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 PWM and PSM Operation
      2. 7.3.2 Low Dropout Operation (100% Duty Cycle)
      3. 7.3.3 Switch Current Limit
      4. 7.3.4 Undervoltage Lockout
      5. 7.3.5 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Enable and Disable (EN)
      2. 7.4.2 Soft Startup (SS/TR)
      3. 7.4.3 Voltage Tracking (SS/TR)
      4. 7.4.4 Power Good Output (PG)
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 1.8-V Output Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design with WEBENCH® Tools
          2. 8.2.1.2.2 Setting the Output Voltage
          3. 8.2.1.2.3 Input and Output Capacitor Selection
          4. 8.2.1.2.4 Soft Startup Capacitor Selection
        3. 8.2.1.3 Application Performance Curves
    3. 8.3 System Examples
      1. 8.3.1 Inverting Power Supply
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Consideration
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
        1. 11.1.2.1 Custom Design With WEBENCH® Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Package Materials Information
      1. 12.1.1 Tape and Reel Information

Package Options

Mechanical Data (Package|Pins)
  • SIL|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.1 PWM and PSM Operation

The TPS82150 includes an on-time (tON) circuitry. This tON, in steady-state operation in PWM and PSM modes, is estimated as:

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Equation 1. TPS82150 TPS82130_EQ_ton.gif

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In PWM mode, the TPS82150 operates with pulse width modulation in continuous conduction mode (CCM) with a tON shown in Equation 1 at medium and heavy load currents. A PWM switching frequency of typically 2.0MHz is achieved by this tON circuitry. The device operates in PWM mode as long as the output current is higher than half the inductor's ripple current estimated by Equation 2.

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Equation 2. TPS82150 EQ_ILripple.gif

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To maintain high efficiency at light loads, the device enters Power Save Mode seamlessly when the load current decreases. This happens when the load current becomes smaller than half the inductor's ripple current. In PSM, the converter operates with reduced switching frequency and with a minimum quiescent current to maintain high efficiency. PSM is also based on the tON circuitry. The switching frequency in PSM is estimated as:

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Equation 3. TPS82150 EQ_FSWPSM.gif

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In PSM, the output voltage rises slightly above the nominal output voltage in PWM mode. This effect is reduced by increasing the output capacitance. The output voltage accuracy in PSM operation is reflected in the electrical specification table and given for a 22-µF output capacitor.

For very small output voltages, an absolute minimum on-time of about 80ns is kept to limit switching losses. The operating frequency is thereby reduced from its nominal value, which keeps efficiency high. Also the off-time can reach its minimum value at high duty cycles. The output voltage remains regulated in such cases.

When VIN decreases to typically 15% above VOUT, the TPS82150 can't enter Power Save Mode, regardless of the load current. The device maintains output regulation in PWM mode.