TPS5431DDA

Part: Texas Instruments TPS5430 / TPS5431

Type: Synchronous Buck Converter

Description: 5.5–36 V input, 3 A continuous output synchronous buck converter with integrated MOSFET, up to 95% peak efficiency, and fixed 500 kHz switching frequency.

Operating Conditions:

• Supply voltage: 5.5–36 V (TPS5430), 5.5–23 V (TPS5431)
• Operating junction temperature: -40 to 125 °C
• Output voltage range: Adjustable down to 1.22 V
• Switching frequency: Fixed 500 kHz

Absolute Maximum Ratings:

• Max supply voltage (VIN): 40 V (for TPS5430), 25 V (for TPS5431)
• Max continuous current: 3 A
• Max storage temperature: 150 °C

Key Specs:

• Quiescent current (not switching): 3 mA (typ), 4.4 mA (max)
• Shutdown current: 18 µA (typ), 50 µA (max)
• Voltage reference accuracy: 1.196 V to 1.245 V (over 0-3A load)
• Internally set free-running frequency: 500 kHz (typ)
• High-side power MOSFET rDS(on): 110 mΩ (typ), 230 mΩ (max)
• Current limit: 4 A (min), 5 A (typ), 6 A (max)
• Internal slow-start time: 8 ms (typ)
• Thermal shutdown trip point: 162 °C (typ)

Features:

• Up to 3-A Continuous (4-A Peak) Output Current
• High Efficiency up to 95% Enabled by 110-mΩ Integrated MOSFET Switch
• Internal Compensation Minimizes External Parts Count
• Fixed 500 kHz Switching Frequency for Small Filter Size
• System Protected by Overcurrent Limiting, Overvoltage Protection and Thermal Shutdown

Applications:

• Consumer: Set-top Box, DVD, LCD Displays
• Industrial and Car Audio Power Supplies
• Battery Chargers, High Power LED Supply
• 12-V/24-V Distributed Power Systems

Package:

• Thermally Enhanced 8-Pin SOIC PowerPAD™ (DDA)

• Wide Input Voltage Range:
  • TPS5430: 5.5 V to 36 V TPS5431: 5.5 V to 23 V
• Up to 3-A Continuous (4-A Peak) Output Current
• High Efficiency up to 95% Enabled by 110-mΩ Integrated MOSFET Switch
• Wide Output Voltage Range: Adjustable Down to 1.22 V with 1.5% Initial Accuracy
• Internal Compensation Minimizes External Parts Count
• Fixed 500 kHz Switching Frequency for Small Filter Size
• Improved Line Regulation and Transient Response by Input Voltage Feed Forward
• System Protected by Overcurrent Limiting, Overvoltage Protection and Thermal
• -40°C to 125°C Operating Junction Temperature Range
• Available in Small Thermally Enhanced 8-Pin SOIC PowerPAD™ Package
• For SWIFT™ Documentation, Application Notes and Design Software, See the TI Website at www.ti.com/swift

APPLICATIONS

• Consumer: Set-top Box, DVD, LCD Displays
• Industrial and Car Audio Power Supplies
• Battery Chargers, High Power LED Supply
• 12-V/24-V Distributed Power Systems

DESCRIPTION

As a member of the SWIFT™ family of DC/DC regulators, the TPS5430/TPS5431 high-output-current PWM converter that integrates a low resistance high side N-channel MOSFET. Included on the substrate with the listed features are a high performance voltage error amplifier that provides tight voltage regulation accuracy under transient conditions; an undervoltage-lockout circuit to prevent start-up until the input voltage reaches 5.5 V; an internally set slow-start circuit to limit inrush currents; and a voltage feed-forward circuit to improve the transient response. Using the ENA pin, shutdown supply current is reduced to 18 μA typically. Other features include an active-high enable, overcurrent limiting, overvoltage protection and thermal shutdown. To reduce design complexity and external component count, TPS5430/TPS5431 feedback loop is internally compensated. The TPS5431 is intended to operate from power rails up to 23 V. The TPS5430 regulates a wide variety of power sources including 24-V bus.

The TPS5430/TPS5431 device is available in a thermally enhanced, easy to use 8-pin SOIC PowerPAD™ package. TI provides evaluation modules and the SWIFT™ Designer software tool to aid in quickly achieving high-performance power supply designs to meet aggressive equipment development cycles.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. SWIFT, PowerPAD are trademarks of Texas Instruments.

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.

ORDERING INFORMATION

• (1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com.
• (2) The DDA package is also available taped and reeled. Add an R suffix to the device type (i.e., TPS5430DDAR). See applications section of data sheet for PowerPAD™ drawing and layout information.

ABSOLUTE MAXIMUM RATINGS

over operating free-air temperature range (unless otherwise noted) (1)(2)

⁽¹⁾ Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

• Consumer: Set-top Box, DVD, LCD Displays
• Industrial and Car Audio Power Supplies
• Battery Chargers, High Power LED Supply
• 12-V/24-V Distributed Power Systems

T₁ = -40 °C to 125°C, VIN = 12.0 V (unless otherwise noted)

PIN ASSIGNMENTS

over operating free-air temperature range (unless otherwise noted) (1)(2)

⁽¹⁾ Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

T₁ = -40 °C to 125°C, VIN = 12.0 V (unless otherwise noted)

PIN ASSIGNMENTS

The TPS5430/TPS5431 protects itself from overheating with an internal thermal shutdown circuit. If the junction temperature exceeds the thermal shutdown trip point, the voltage reference is grounded and the high-side MOSFET is turned off. The part is restarted under control of the slow start circuit automatically when the junction temperature drops 14°C below the thermal shutdown trip point.

Figure 11 shows the schematic for a typical TPS5430 application. The TPS5430 can provide up to 3-A output current at a nominal output voltage of 5 V. For proper thermal performance, the exposed PowerPAD^{TM}underneath the device must be soldered down to the printed-circuit board.

Figure 11. Application Circuit, 12-V to 5.0-V

Design Procedure

The following design procedure can be used to select component values for the TPS5430. Alternately, the SWIFT™ Designer Software may be used to generate a complete design. The SWIFT™ Designer Software uses an iterative design procedure and accesses a comprehensive database of components when generating a design. This section presents a simplified discussion of the design process.

To begin the design process ^a few parameters must be decided upon. The designer needs to know the following:

• •Input voltage range
• •Output voltage
• •Input ripple voltage
• •Output ripple voltage
• Output current rating
• •Operating frequency