SLUSAR9D December   2011  – December 2021 TPS28225-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Switching Characteristics
    7. 6.7 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 Undervoltage Lockout (UVLO)
      2. 7.3.2 Output Active Low
      3. 7.3.3 Enable/Power Good
      4. 7.3.4 3-State Input
      5. 7.3.5 Bootstrap Diode
      6. 7.3.6 Upper and Lower Gate Drivers
      7. 7.3.7 Dead-Time Control
      8. 7.3.8 Thermal Shutdown
    4. 7.4 Device Functional Modes
  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 Switching the MOSFETs
      3. 8.2.3 Application Curves
  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 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.1 Design Requirements

The DC-DC converter in Figure 8-4 displays the schematic of the TPS28225 in a multiphase high-current step-down power supply (only one phase is shown). This example schematic uses a single high-side MOSFET and two low-side MOSFETs the latter connected in parallel. The TPS28225 is controlled by multiphase buck DC/DC controller like TPS40090-Q1. As TPS28225 has internal shoot-through protection, only one PWM control signal is required for each channel.

The VRM example schematic is capable of driving 35 A per phase. In this example it has a nominal input voltage of 12 V within a tolerance range of ±5%. The switching frequency is 500 kHz. The nominal duty cycle is 10%, therefore the low-side MOSFETs are conducting 90% of the time. By choosing lower RDS(on) the conduction losses of the switching elements are minimized. The TPS28225 is controlled by multiphase buck DC/DC controller like TPS40090-Q1.

Table 8-1 Design Parameters
DESIGN PARAMETER VALUE
Supply Voltage 12 V ± 5%
Output Voltage 0.83 V to 1.6 V
Frequency 500 kHz
Efficiency 87%
Peak-to-peak voltage on load current (0 A –90 A ) <160 mV
GUID-E5F16D16-0BA1-4B00-8BE3-78B609827B8F-low.gif
Additional information is available in What MOSFET Driver Can Do to Boost the Performance of VRM Design.
Figure 8-4 One of Four Phases Driven by TPS28225 Driver in 4-phase VRM Example Schematic for Efficiency Measurement