SLVSDI8C october   2016  – august 2023 TPS568215

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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 Timing Requirements
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  PWM Operation and D-CAP3 Control Mode
      2. 7.3.2  Eco-mode Control
      3. 7.3.3  4.7 V LDO and External Bias
      4. 7.3.4  MODE Selection
      5. 7.3.5  Soft Start and Pre-biased Soft Start
      6. 7.3.6  Enable and Adjustable UVLO
      7. 7.3.7  Power Good
      8. 7.3.8  Overcurrent Protection and Undervoltage Protection
      9. 7.3.9  Out-of-Bounds Operation
      10. 7.3.10 UVLO Protection
      11. 7.3.11 Thermal Shutdown
      12. 7.3.12 Output Voltage Discharge
    4. 7.4 Device Functional Modes
      1. 7.4.1 Light Load Operation
      2. 7.4.2 Standby Operation
  9. 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 External Component Selection
          1. 8.2.2.1.1 Output Voltage Set Point
          2. 8.2.2.1.2 Switching Frequency and Mode Selection
          3. 8.2.2.1.3 Inductor Selection
          4. 8.2.2.1.4 Output Capacitor Selection
          5. 8.2.2.1.5 Input Capacitor Selection
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
      2. 9.1.2 Development Support
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.4 MODE Selection

TPS568215 has a MODE pin that can offer 12 different states of operation as a combination of Current Limit, Switching Frequency and Light Load operation. The device can operate at two different current limits ILIM-1 and ILIM to support an output continuous current of 6 A, 8 A respectively. The TPS568215 is designed to compare the valley current of the inductor against the current limit thresholds so understand that the output current is half the ripple current above the valley current. TPS568215 can operate at three different frequencies of 400 kHz, 800 kHz and 1200 kHz and also can choose between Eco-mode™ and FCCM mode. The device reads the voltage on the MODE pin during start-up and latches onto one of the MODE options listed below in table 3. The voltage on the MODE pin can be set by connecting this pin to the center tap of a resistor divider connected between VREG5 and AGND. A guideline for the top resistor (RM_H) and the bottom resistor (RM_L) as 5% resistors is shown in Table 3. It is important that the voltage for the MODE pin is derived from the VREG5 rail only must internally this voltage is referenced to detect the MODE option. The MODE pin setting can be reset only by a VIN power cycling.

Table 7-3 Mode Pin Resistor Settings
RM_L (kΩ) RM_H (kΩ) Light Load Operation Current Limit Frequency (kHz)
5.1300FCCMILIM-1400
10200FCCMILIM400
20160FCCMILIM-1800
20120FCCMILIM800
51200FCCMILIM-11200
51180FCCMILIM1200
51150DCMILIM-1400
51120DCMILIM400
5191DCMILIM-1800
5182DCMILIM800
5162DCMILIM-11200
5151DCMILIM1200

Figure 7-1 below shows the typical start-up sequence of the device after the enable signal crosses the EN turn-on threshold. After the voltage on VREG5 crosses the rising UVLO threshold it takes about 500 us to read the first mode setting and approximately 100 us from there to finish the last mode setting. The output voltage starts ramping after the mode reading is done.

GUID-7F0A7E6F-CA37-4D0B-BBBA-06D4CB89FF49-low.gifFigure 7-1 Power-Up Sequence