TPS5431

Part: TPS5430, TPS5431 — Texas Instruments

Type: Step-Down Converter

Description: 5.5 V to 36 V input, 3 A continuous (4 A peak) output current step-down PWM converter with an integrated 110 mΩ high-side MOSFET and up to 95% efficiency.

Operating Conditions:

• Supply voltage: 5.5 to 36 V (TPS5430), 5.5 to 23 V (TPS5431)
• Operating temperature: -40 to 125 °C (junction)

Absolute Maximum Ratings:

• Max junction/storage temperature: 150 °C

Key Specs:

• Maximum continuous output current: 3 A (4 A peak)
• High-side MOSFET on-resistance: 110 mΩ
• Switching frequency: 500 kHz (fixed)
• Reference / minimum output voltage: adjustable down to 1.22 V (1.5% initial accuracy)
• Undervoltage lockout start threshold: 5.5 V
• Shutdown supply current: 18 μA (typical, using ENA pin)
• Peak efficiency: up to 95%

Features:

• Integrated 110 mΩ high-side N-channel MOSFET
• Internal loop compensation to minimize external component count
• Voltage feedforward for improved line regulation and transient response
• System protection via overcurrent limiting, overvoltage protection, and thermal shutdown
• Internally set slow-start circuit to limit inrush current
• Active-high enable (stop switching below 0.5 V, float to enable)

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:

• 8-pin HSOP (SOIC PowerPAD, DDA package)

TPS5430, TPS5431

SLVS632F -JANUARY 2006-REVISED DECEMBER 2014

• 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

TJ = -40°C to 125°C, VIN = 12 V (unless otherwise noted)

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

• (1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

(2) Maximum power dissipation may be limited by overcurrent protection

(3) Power rating at a specific ambient temperature TA should be determined with a junction temperature of 125°C. This is the point where distortion starts to substantially increase. Thermal management of the final PCB should strive to keep the junction temperature at or below 125°C for best performance and long-term reliability. See Thermal Calculations in applications section of this data sheet for more information.

• (4) Test boards conditions:

1. (a) 3 in x 3 in, 2 layers, thickness: 0.062 inch.
2. (b) 2 oz. copper traces located on the top and bottom of the PCB.
3. (c) 6 thermal vias in the PowerPAD area under the device package.

• (5) Test board conditions:

1. (a) 3 in x 3 in, 4 layers, thickness: 0.062 inch.
2. (b) 2 oz. copper traces located on the top and bottom of the PCB.
3. (c) 2 oz. copper ground planes on the 2 internal layers.
4. (d) 6 thermal vias in the PowerPAD area under the device package.

The TPS543x is a 3-A, step down regulator with an integrated high side MOSFET. This device is typically used to convert a higher DC voltage to a lower DC voltage with a maximum available output current of 3 A. Example applications are: High Density Point-of-Load Regulators for Set-top Box, DVD, LCD and Plasma Displays, High Power LED Supply, Car Audio, Battery Chargers, and other 12-V and 24-V Distributed Power Systems. Use the following design procedure to select component values for the TPS543x. This procedure illustrates the design of a high frequency switching regulator. Alternatively, use the WEBENCH software to generate a complete design. The WEBENCH software uses an iterative design procedure and accesses a comprehensive database of components when generating a design.

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