SLVSDT1C July   2017  – June 2020 TPSM82480

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application space
      2.      Efficiency vs Output Current space 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 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  Enable and Shutdown (EN)
      2. 7.3.2  Soft-Start (SS), Pre-biased Output
      3. 7.3.3  Tracking (TR)
      4. 7.3.4  Output Voltage Select (VSEL)
      5. 7.3.5  Forced PWM (MODE)
      6. 7.3.6  Power Good (PG)
      7. 7.3.7  Thermal Good (TG)
      8. 7.3.8  Active Output Discharge
      9. 7.3.9  Undervoltage Lockout (UVLO)
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Pulse Width Modulation (PWM) Operation
      2. 7.4.2 Power Save Mode (PSM) Operation
      3. 7.4.3 Minimum Duty Cycle and 100% Mode Operation
      4. 7.4.4 Phase Shifted Operation
      5. 7.4.5 Phase Add/Shed and Current Balancing
      6. 7.4.6 Current Limit and Short Circuit Protection
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Setting the Output Voltage
        2. 8.2.2.2 Setting VOUT2 Using the VSEL Feature
        3. 8.2.2.3 Feedforward Capacitance
        4. 8.2.2.4 Output Capacitor Selection
        5. 8.2.2.5 Input Capacitor Selection
        6. 8.2.2.6 Soft-Start Capacitor Selection
        7. 8.2.2.7 Tracking
        8. 8.2.2.8 Thermal Good
      3. 8.2.3 Application Curves
    3. 8.3 System Examples
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    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 Tape and Reel Information

Package Options

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

8.2.2.4 Output Capacitor Selection

The recommended minimum output capacitance is 4 x 22 µF, that can be ceramic capacitors exclusively. A larger value of output capacitance may be needed for VOUT ≤ 1.8 V, to improve transient response performance, as well as for VOUT > 3.3 V to compensate for voltage bias effects of the ceramic capacitors. The usage of an additional feed forward capacitor can help reducing amount of output capacitance that is needed to achieve a certain transient response target (see Table 3).

The TPSM82480 provides a wide output voltage range from 0.6 V to 5.5 V. While stability is a critical criteria for the output filter selection, the output capacitor value also determines transient response behavior, ripple and accuracy of VOUT. The internal compensation is designed for an output capacitance range from approxiimately 50 µF to 150 µF effectively. Because ceramic capacitors are used preferably, this translates into nominal values of 4 x 22 µF to 4 x 47 µF and mainly depends on the output voltage. The following table shows recommended capacitor combinations for different output voltage ranges. Combinations without checkmark may not be suitable for all applications:

Table 2. Recommended Output Capacitor Values (nominal)(1)

VOUT ≤ 1.0 V 1.0 V ≤ VOUT ≤ 3.3 V VOUT ≥ 3.3 V
2 × 22 µF
4 × 22 µF √
4 × 47 µF √ √ √
6 × 47 µF
(1) The values in the table are nominal values. The effective capacitance can differ significantly, depending on package size, voltage rating and dielectric material.

space

Beyond the recommendations in Table 2, other values can be chosen and might be suitable depending on VOUT and actual effective capacitance. In such case, stability needs to be checked within the actual environment.

Even if the output capacitance is sufficient for stability, a different value might be desirable to improve the transient response behavior. Table 3 can be used to determine capacitor values for specific transient response targets:

Table 3. Recommended Output Capacitor Values (nominal)

Output Voltage [V] Load Step [A] Output Capacitor Value(1) Feedforward Capacitor(1) Typical Transient Response Accuracy
±mV ±%
1.0 0 - 3 4 x 47 µF - 50 5
3 - 6 50 5
1.8 0 - 3 4 x 22 µF 36 pF 50 3
3 - 6 50 3
2.5 0 - 3 4 x 22 µF 36 pF 62 2.5
3 - 6 50 2
3.3 0 - 3 4 x 47 µF 36 pF 100 3
3 - 6 80 2.5
(1) The values in the table are nominal values. The effective capacitance can differ significantly, depending on package size, voltage rating and dielectric material.

space

The architecture of the TPSM82480 allows the use of tiny ceramic output capacitors with low equivalent series resistance (ESR). These capacitors provide low output voltage ripple and are recommended. To keep its low resistance up to high frequencies and to get narrow capacitance variation with temperature, it is recommended to use X5R or X7R dielectrics. Using even higher values than demanded for stability and transient response has further advantages like smaller voltage ripple and tighter dc output accuracy in Power Save Mode.