SLVSEC6D June   2019  – March 2020 TPS62840

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
      2.      Efficiency versus Load Current (VOUT = 1.8 V)
  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
      2. 8.3.2 Soft Start
      3. 8.3.3 Mode Selection: Power-Save Mode (PFM/PWM) or Forced PWM Operation (FPWM)
      4. 8.3.4 Output Voltage Selection (VSET)
      5. 8.3.5 Undervoltage Lockout UVLO
      6. 8.3.6 Switch Current Limit / Short Circuit Protection
      7. 8.3.7 Output Voltage Discharge
      8. 8.3.8 Thermal Shutdown
      9. 8.3.9 STOP Mode
    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
  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 Inductor Selection
        2. 9.2.2.2 Output Capacitor Selection
        3. 9.2.2.3 Input Capacitor Selection
      3. 9.2.3 Application Curves
    3. 9.3 System Example
  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 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

9.2.2.3 Input Capacitor Selection

Because the buck converter has a pulsating input current, a low-ESR input capacitor is required for best input voltage filtering to minimize input voltage spikes. For most applications, a 4.7-µF input capacitor is sufficient.

When operating from a high impedance source, a larger input buffer capacitor is recommended to avoid voltage drops during start-up and load transients.

The input capacitor can be increased without any limit for better input voltage filtering. The leakage current of the input capacitor adds to the overall quiescent current. Table 6 shows a selection of input and output capacitors.

Table 6. List of Possible Capacitors(1)

CAPACITOR VALUE [μF] CAPACITOR TYPE SIZE IMPERIAL (METRIC) SIZE [L x W x T] SUPPLIER
4.7 GRM155R61A475MEAAD 0402
(1005)		 [1mm x 0.5mm x 0.65mm max.] muRata
4.7 GRM31CR71H475MA12L 1206
(3216)		 [3.2mm x 1.6mm x 1.8mm max.] muRata
4.7 C1608X7S1A475M080AC 0603
(1608)		 [1.6mm x 0.8mm x 1.0mm max.] TDK
10 GRM155R60J106ME15D 0402
(1005)		 [1mm x 0.5mm x 0.65mm max.] muRata