SLUSD62 December   2017 TPS40345

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 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 Voltage Reference
      2. 7.3.2 Enable Functionality, Start-Up Sequence and Timing
      3. 7.3.3 Soft-Start Time
      4. 7.3.4 Oscillator and Frequency Spread Spectrum (FSS)
      5. 7.3.5 Overcurrent Protection
      6. 7.3.6 Drivers
      7. 7.3.7 Prebias Start-Up
      8. 7.3.8 Power Good
      9. 7.3.9 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Modes of Operation
        1. 7.4.1.1 UVLO
        2. 7.4.1.2 Disable
        3. 7.4.1.3 Calibration
        4. 7.4.1.4 Converting
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Selecting the Switching Frequency
        2. 8.2.2.2  Inductor Selection (L1)
        3. 8.2.2.3  Output Capacitor Selection (C12)
        4. 8.2.2.4  Peak Current Rating of Inductor
        5. 8.2.2.5  Input Capacitor Selection (C8)
        6. 8.2.2.6  MOSFET Switch Selection (Q1 and Q2)
        7. 8.2.2.7  Bootstrap Capacitor (C6)
        8. 8.2.2.8  VDD Bypass Capacitor (C7)
        9. 8.2.2.9  BP Bypass Capacitor (C5)
        10. 8.2.2.10 Short-Circuit Protection (R11)
        11. 8.2.2.11 Feedback Divider (R4, R5)
        12. 8.2.2.12 Compensation: (C2, C3, C4, R3, R6)
      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 Device Support
      1. 11.1.1 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 Community 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

1 Features

  • Input Voltage Range From 3 V to 20 V
  • 600-kHz Switching Frequency
  • High- and Low-Side FET RDS(on) Current Sensing
  • Programmable Thermally Compensated OCP Levels
  • Programmable Soft-Start
  • 600-mV, 1.3% Reference Voltage
  • Voltage Feed-Forward Compensation
  • Supports Prebiased Output
  • Frequency Spread Spectrum
  • Thermal Shutdown Protection at 145°C
  • 10-Pin 3-mm × 3-mm VSON Package With Ground Connection to Thermal Pad

2 Applications

  • POL Modules
  • Printers
  • Digital TVs
  • Telecom

3 Description

The TPS40345 is a synchronous buck controller that operates from 3-V to 20-V input and which can be used in cost-optimized applications. The controller implements a voltage-mode control architecture with input-voltage feed-forward compensation that responds instantly to a change in input voltage. The switching frequency is fixed at 600 kHz.

The frequency spread spectrum (FSS) feature adds to the switching frequency, significantly reducing the peak EMI noise and making it much easier to comply with EMI standards.

The TPS40345 offers design with a variety of user-programmable functions, including soft-start, overcurrent protection (OCP) levels, and loop compensation.

OCP level may be programmed by a single external resistor connected from the LDRV pin to circuit ground. During initial power on, the TPS40345 enters a calibration cycle, measures the voltage at the LDRV pin, and sets an internal OCP voltage level. During operation, the programmed OCP voltage level is compared to the voltage drop across the low-side FET when it is on to determine whether there is an overcurrent condition. The TPS40345 then enters a shutdown and restart cycle until the fault is removed.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
TPS40345 VSON (10) 3.00 mm × 3.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Application Diagram

TPS40345 simpschem_lusd62.gif