SLVSD44A September   2017  – July 2018 TPS63710

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
      2.      Efficiency vs output current for VOUT = -1.8V
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1. Table 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 Low Noise Reference System
      2. 7.3.2 Duty Cycle
      3. 7.3.3 Enable
      4. 7.3.4 Undervoltage Lockout
      5. 7.3.5 Thermal Shutdown
      6. 7.3.6 Power Good Output
    4. 7.4 Device Functional Modes
      1. 7.4.1 Soft-Start
      2. 7.4.2 VOUT Discharge
      3. 7.4.3 Current Limit
      4. 7.4.4 CCP Capacitor Precharge
      5. 7.4.5 PWM Operation
  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 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Setting the Output Voltage
        3. 8.2.2.3 Inductor Selection
        4. 8.2.2.4 Capacitor Selection
          1. 8.2.2.4.1 CCP Capacitor
          2. 8.2.2.4.2 Input Capacitor
          3. 8.2.2.4.3 Output Capacitor
      3. 8.2.3 Application Curves
        1. 8.2.3.1 Parameter Measurement Information
    3. 8.3 System Examples
      1. 8.3.1 Typical Application for Powering the Negative Rail of a Gallium Nitride (GaN) Power Amplifier
      2. 8.3.2 Typical Application for Powering the Negative Rail of an ADC or DAC
      3. 8.3.3 Typical Application for Laser Diode Bias
  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 Device Support
      1. 11.1.1 Custom Design With WEBENCH® Tools
      2. 11.1.2 Third-Party Products Disclaimer
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.5 PWM Operation

The converter operates with a fixed-frequency, pulse-width-modulated control. In the OFF-time, the rectifier switch (RECT) and the high-side switch (HSD) are turned on to charge CCP to the input voltage. As well, the inductor current ramps down, continuing to charge the output capacitor. During the ON-time, the low-side switch (LSD) is closed and HSD and RECT are opened. CCP inverts the supply voltage onto SW, and the inductor current is ramped up. The LC output filter filters the SW voltage, just like in a step-down converter. Charging the CCP capacitor during the OFF-time limits the maximum duty cycle. The upper limit of the duty cycle is 70% to allow charging the CCP capacitor in the remaining 30%.

Lower negative voltages require higher positive supply voltages. For an output voltage of -1.8 V, a minimum input voltage of 4.5 V is sufficient while for an output voltage of -3.3 V, the input voltage has to be above 6 V. See Figure 36 to Figure 38 for the relation of input voltage, output voltage and temperature vs output current.

For high input voltages and, in absolute value, small output voltages, the device operates with its minimum on-time (ton,min) to generate the duty cycle required for this VIN and VOUT ratio. This means that, for such cases, the switching frequency is lower than fS.