SLVSCE3A June   2014  – June 2014 TPS82740A , TPS82740B

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1. 3.1 Typical Application
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
    2. Table 1. Output Voltage Setting TPS82740A
    3. Table 2. Output Voltage Setting TPS82740B
  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 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 DCS-Control
      2. 9.3.2 LOAD Switch
      3. 9.3.3 Output Voltage Selection (VSEL1, VSEL2, VSEL3)
      4. 9.3.4 Output Discharge Function (VOUT and LOAD)
      5. 9.3.5 Internal Current Limit
      6. 9.3.6 CTRL / DVS (Dynamic Voltage Scaling TPS62741)
    4. 9.4 Device Functional Modes
      1. 9.4.1 Enable / Shutdown
      2. 9.4.2 Soft Start
      3. 9.4.3 POWER GOOD OUTPUT (PG)
      4. 9.4.4 Automatic Transition into 100% Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Input Capacitor Selection
          1. 10.2.2.1.1 Input Buffer Capacitor Selection
        2. 10.2.2.2 Output Capacitor Selection
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
    3. 12.3 Surface Mount Information
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Links
    2. 13.2 Trademarks
    3. 13.3 Electrostatic Discharge Caution
    4. 13.4 Glossary
  14. 14Mechanical, Packaging, and Orderable Information
    1. 14.1 Tape and Reel Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • SIP|9
Thermal pad, mechanical data (Package|Pins)
Orderable Information

10.2.2.1.1 Input Buffer Capacitor Selection

In addition to the small ceramic input capacitor a larger buffer capacitor CBuf is recommended to reduce voltage drops and ripple voltage. When using battery chemistries like Li-SOCl2, Li-SO2, Li-MnO2, the impedance of the battery has to be considered. These battery types tend to increase their impedance depending on discharge status and often can support output currents of only a few mA. Therefore a buffer capacitor is recommended to stabilize the battery voltage during DC/DC operations e.g. for a RF transmission. A voltage drop on the input of the TPS82740 during DC/DC operation impacts the advantage of the step down conversion for system power reduction. Furthermore the voltage drops can fall below the minimum recommended operating voltage of the device and leads to an early system cut off. Both effects reduce the battery life time. To achieve best performance and to extract the most energy out of the battery a good procedure is to select the buffer capacitor value for an voltage drop below 50mVpp during DC/DC operation. The capacitor value strongly depends on the used battery type, as well the current consumption during a RF transmission as well the duration of the transmission.